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I am looking for some information in regards DDoS in the follow scenario: I have a server that is behind a Cisco Guard and it will be DDoS'ed, I only care about a set list of IPS that by not means are the attackers. Is it possible to null all other ips but this list to actually get any response to my server or in the long run no matter what I do if they have enough DDoS power I will just go down like a flie ? Is there any recommended company out there that can actually cope with a DDoS ? My server will mainly run several clients that will get connected to a external server and all it needs access to is my local MySQL the the private network so I can access it. There will be no other services runnings such as web or ftp etc at least not to the external ips of the server if i ever have to have any of these service they will be on the private network. The MySQL will be available externally only to 1 safe ip not known by anyone but me and internally at localhost + private network. Are there any solutions ?
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This is a about DoS and DDoS mitigation. I found a massive traffic spike on a website that I host today; I am getting thousands of connections a second and I see I'm using all 100Mbps of my available bandwidth. Nobody can access my site because all the requests time out, and I can't even log into the server because SSH times out too! This has happened a couple times before, and each time it's lasted a couple hours and gone away on its own. Occasionally, my website has another distinct but related problem: my server's load average (which is usually around .25) rockets up to 20 or more and nobody can access my site just the same as the other case. It also goes away after a few hours. Restarting my server doesn't help; what can I do to make my site accessible again, and what is happening? Relatedly, I found once that for a day or two, every time I started my service, it got a connection from a particular IP address and then crashed. As soon as I started it up again, this happened again and it crashed again. How is that similar, and what can I do about it?
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How does asymmetric crypto work? For example, if you use PGP in emails, you generate a private key that is known only to you and a public key, which is available to everyone. Is there a simple way to explain, why you need a private key and why no one can decrypt the message with just the public key? I think of an explanation like for example with prime numbers: If you multiply two large prime numbers, you get a huge non-prime number with only two (large) prime factors. Factoring that number is a non-trivial operation, and that fact is the source of a lot of Cryptographic algorithms. (See for more information.) The product of the two prime numbers can be used as a public key The primes themselves as a private key. So the private key is the knowledge of two very large prime numbers for easy understanding lets take the simple example (very large) prime numbers: 3 and 5: private key: the knowlege of 3 and 5 the public key is just those numbers multiplied: 15 you cannot find out 3 and 5, so the message encrypted with 15 is ... Here is a quite good explanation already, but it is not clear enough: Can you please add an example with those numbers?
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I've always been interested in encryption but I have never found a good explanation (beginners explanation) of how encryption with public key and decryption with private key works. How does it encrypt something with one key and decipher it with another key?
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I know this may sound strange but it does happen not every time the fridge turns off only some times the tv and fridge are on different circuits should I get a filter of some kind or trash the tv or fridge any suggestion would be a help
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I have my computer connected to my TV via HDMI. Every time something electrical happens (fridge turns on, stove sparks, etc), the image on the TV goes black for a second and then comes back on. And before anyone asks, trust me, I checked other options, it is perfectly in sync with the fridge/stove/etc and not some random coincidence Anyone have any ideas as to what is causing this or how I fix it? Or should I just get a new HDMI cable? The lights do not flicker or dim when this happens. Also, if it is on the same circuit, how do I figure that out? And will connecting the TV to a regular surge protector work, or do I need to put it on a voltage stabilizer?
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I have a String that contains method names with arguments.I wanna execute all methods.How can I do that.Consider following input - String s="second(first(\"string1\"))"; where first(String s) and second(String s) are two method in my class. Note that when I change Strings s=second(first("string1")); manually,its working fine, I'm looking for some dynamic approach to do same. (If possible then without reflection).
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What is reflection, and why is it useful? I'm particularly interested in Java, but I assume the principles are the same in any language.
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I just got a message when signing into a site that Open ID 2 with Google is ending: Will this affect me signing into the network with my Google Account?
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Apparently, for some reason, . I got this notice while logging in with Disqus, but not with Stack Exchange. So... is Stack Exchange going to be affected by this? Do I need, or want, to add extra login methods to my Stack Exchange account to ensure I can still log in come April?
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Let us assume that in all fonts you are using the transpose operator ⊤ has form similar to the Latin letter T in Computer Modern. How on earth do I move ⊤ to the left, and, if necessary, down, automatically? On the one hand, ⊤ could be moved slightly to the left in $W^{\top}T^{\top}M^{\top}$, but not too much. On the other hand, the vertical and horizontal spacing between the letter and the following ⊤ in $A^{\top} L^{\top} u^{\top} w^{\top}$ is horribly large: In other words, I need a universal macro, say, \transpose{stuff} that would automatically take care of placing the down tack symbol as a right superscript of stuff but not wasting space. Of course, "universal" is not well-defined; we just want that the macro does the right job for as many fonts and letters as possible. (An aside: the uses fixed horizontal length -1\mu and no vertical space change. This is not good enough for me.) My attempts to do horizontal and vertical spacing at the same time with LaTeX3 have no visible effect. In my example below, tl_case does not work as I expect, e.g., \transpose{u} is the same as u^{\top} (which should not be the case): \tl_new:N\l_tl_lastTokenOfList \NewDocumentCommand{\transpose}{m}{ \tl_set:Nn \l_tl_lastTokenOfList {\tl_item:nn {#1} {-1}} #1^{\tl_case:NnTF \l_tl_lastTokenOfList { {A}{\mkern-3mu\top} {L}{\mkern-3mu\top} {u}{\mkern-3mu\raisebox{-.1ex}{\top}} {w}{\mkern-3mu\raisebox{-.1ex}{\top}} } {} {\top} } }
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I would like that the transpose in the following has the same height in both examples, is there a possibility to make the transpose sign ignore the boxes above the charater? \documentclass{article} \usepackage{amsmath} \begin{document} \newcommand{\vect}[1]{\mathbf{#1}} \newcommand{\vA}{\vect{A}} \newcommand{\dvect}[1]{\vect{\dot{#1}}} \begin{align} {_\mathrm{K}}\dvect{\hat{\vA}}^\top \quad {_\mathrm{K}}\dvect{\vA}^\top \quad\quad {_\mathrm{K}}\vA^\top \end{align} \end{document} {_\mathrm{K}}\dvect{\vA}^\top \quad {_\mathrm{K}}\vA^\top \end{align} \end{document}
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Let $f=X^n-1$ and $g=X^m-1$ be two polynomials. Show that: $$\left(f,g\right)=X^{\left(n,m\right)}-1,$$ where $\left(a,b\right)=$ greatest common divisor of $a$ and $b$.
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For all $a, m, n \in \mathbb{Z}^+$, $$\gcd(a^n - 1, a^m - 1) = a^{\gcd(n, m)} - 1$$
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Referenced question: It has tags: symlink, vagrant, 'virtualbox,chef` As the title mentions, it's about symlink mainly, other tags are just assocation with the context of the question. If you see the view of the question, the question appears as if this is a virtualbox question. I am not sure of the algorithm it uses to pick a tag to show in the page, but I think there should be a way to pick primary tag, it could be as simple as respecting the order by which it was added in the question.
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As far as I know, if I have some tags in a question, system will choose the tag which has more questions as main tag (shows in title of page) But, sometimes this is not correct. For example, I have a question about PhoneGap which applies to both android and iOS. So my question is about PhoneGap, not Android. but system chooses Android as main tag... Is there any way to manually choose the main tag of a question? if not, Isn't it better to have a feature like this?
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I was using Euler's formula $ e^{ix} = \cos(x) + i \sin(x)$ with the case when $ x = 2\pi$. $$ e^{i2\pi} = \cos(2\pi) + i\sin(2\pi) = 1 + 0i $$ So I end up with the identity $ e^{i2\pi} = 1$. Now, if I apply $\ln$ it goes $$ \ln e^{i2\pi}=\ln1$$ $$ i2\pi = \ln1$$ How $\ln1=0$, Should be that $i2\pi=0$ its true, or not? The first implication I found its that you can divide any imaginary number by zero. $$ {ai\over 0} = {ai\over i2\pi} = {a\over 2\pi}$$ What don you think?
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I was trying to solve for $i^i$. I got distracted and did the following: $e^{i \theta} = \cos(\theta) + i\sin(\theta)$ $e^{i 2\pi} = cos(2\pi) + i\sin(2\pi) = 1$ ||| Take ln() of two sides of equation: $\ln(e^{i2\pi}) = \ln(1)$ $i2\pi = 0$ Clearly this is false. What did I do wrong?
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Is there a physics argument, based on scaling, that leads to the conclusion that an elephant and a human could jump about same height? Could this be extended to any two creatures with different masses?
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The following question was put on hold: It reminded me of an exercise (24a) on that exact topic in Arnold's "Mathematical Methods of Classical Mechanics". The solution he gives goes like that: For a jump of height h one needs energy proportional to $L^3h$, and the work accomplished by muscular strength $F$ is proportional to $FL$. The force $F$ is proportional to $L^2$ (since the strength of the bones is proportional to their section). Therefore, $L^3h$~$L^2L$, i.e. the height of a jump does not depend on the size of the animal. In fact, a jerboa and a kangaroo can jump to approximately the same height. The comments of the above question tended to dismiss that argument. What's wrong with it? Addendum: It seems obvious that not all animals jump exactly to the same height, given their different physiologies/shapes. Some of them can't jump at all. The question is to be understood in the following spirit: if we plotted jumping height vs animal size for a lot of different species, would there be a correlation? I don't mean there is no spread; I totally expect a big spread due to the other factors involved. Second addendum: Some interesting points have been raised in comments and answers. I will accept an answer that incorporates: the domain of validity of Arnold's argument (or explain why it is never valid), the effect of air drag on very small jumpers and the impossibility of very large animals. Bonus points for documenting the yet elusive jumping elephant and plotting jumping height vs size for different species ;)
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I am working on a game, creating a basic, Model-View-Controller, setup. I am trying to create three variables, a Model, a View which takes a pointer to model and a controller which takes a pointer to Model and View. However I am getting an error saying that the constructor for Views(Model*) has been declared implicitly and cannot be referenced as it has been deleted. I have attempted many things but have yet to find a solution to this. Any help would be greatly appreciated! Below is all the code in question, I can include anything else that is requested! From Game.h: #include "Controller.h" #include "Model.h" #include "Views.h" class Game { public: Game(); ~Game(); int launch(); Controller contrl; Model model; Views view; }; From Game.cpp Game::Game() { model = Model(); view = Views(&model); // <- gives error contrl = Controller(&model, &view); } Views.h: #include <SFML\Graphics.hpp> #include "Model.h" class Views { public: Views(); Views(Model*); ~Views(); int render(); sf::RenderWindow window; Model* model; }; Views.cpp: Views::Views() { } Views::Views(Model* m) { model = m; } Views::~Views() { }
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I often find myself in a situation where I am facing multiple compilation/linker errors in a C++ project due to some bad design decisions (made by someone else :) ) which lead to circular dependencies between C++ classes in different header files (can happen also in the same file). But fortunately(?) this doesn't happen often enough for me to remember the solution to this problem for the next time it happens again. So for the purposes of easy recall in the future I am going to post a representative problem and a solution along with it. Better solutions are of-course welcome. A.h class B; class A { int _val; B *_b; public: A(int val) :_val(val) { } void SetB(B *b) { _b = b; _b->Print(); // COMPILER ERROR: C2027: use of undefined type 'B' } void Print() { cout<<"Type:A val="<<_val<<endl; } }; B.h #include "A.h" class B { double _val; A* _a; public: B(double val) :_val(val) { } void SetA(A *a) { _a = a; _a->Print(); } void Print() { cout<<"Type:B val="<<_val<<endl; } }; main.cpp #include "B.h" #include <iostream> int main(int argc, char* argv[]) { A a(10); B b(3.14); a.Print(); a.SetB(&b); b.Print(); b.SetA(&a); return 0; }
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I am working on a custom carrier board using a TI microcontroller as the master and an ADC IC as the slave. It appears that sometimes SCL will stay high when it shouldn't, almost like the master releases it. We only get this fault condition on a reset of the MCU (or total system power cycle) but it does not happen every time, maybe one out of ten on average. Data transfer will be fine most of the time, until one of the unlucky resets causes the issues. You can see in the image below that after the address byte is sent SCL just goes high after a few clock pulses. Any ideas?
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I have a problem with an I2C communication and want you to ask whether there is a better solution than mine. I am programming an STM32F103 at the moment. There is one sensor (MPU6050) which is connected via I2C to the STM32. I recognized that if I reset the STM32 a few times, the STM32 gets stuck (or got an timeout error) during the initialization of the I2C. The timeout error was during the wait of the busy flag. So the I2C communication was "occupied". The MPU6050 is the only other I2C device (slave). In my opinion there is an error, because I was reading a register from the MPU6050 when I reset the STM32. So the MPU6050 never gets the stop condition. I do not know how to reset the I2C connection, when the bus is "occupied" (by the MPU6050). So my solution would be to do a hardware reset with a transmission gate of the MPU6050. Is there maybe a simpler software solution? Thanks for the help.
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How do I get stack traces in Perl?
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Is there a way I can access (for printout) a list of sub + module to arbitrary depth of sub-calls preceding a current position in a Perl script? I need to make changes to some Perl modules (.pm's). The workflow is initiated from a web-page thru a cgi-script, passing input through several modules/objects ending in the module where I need to use the data. Somewhere along the line the data got changed and I need to find out where.
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The knowledge of regional languages is necessary for bank officers because they are to understand what their customers say. I tried google for meaning/usage of the phrase they are to as used in above given sentence but couldn't find anything relevant, I doubt if any such phrase even exists. To my hears using have instead of are sounds better. Please tell if the phrase they are to used in above sentence is correct ? If yes, Does it imply the same meaning as using have instead of are ?
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Could anybody clear it to me whether these two sentence are grammatically equal? If not, what is the difference? 1) They must use some methods... 2) They are to use some methods...
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I'm doing a sample test question in C and can't explain the 'right answer'. The question is what is the output of: #include<stdio.h> #include<stdlib.h> struct st{ int a; char b; }; int main() { struct st *st_ptr; st_ptr = malloc(sizeof(struct st)); printf("%d\n",sizeof(struct st)); return 0; } And possible answers a) 8 b) 5 c) 0 d) none of the mentioned I figured the answer was B (4 bytes + 1 byte) but they say the right answer is A (8 bytes). Their explanation is: Maximum size of the data type is 4 byte(int) in the structure. Can someone perhaps explain the right answer better? Or is their right answer actually wrong.
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Why does the sizeof operator return a size larger for a structure than the total sizes of the structure's members?
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I have a list of empty lists as such: some_lists = [[]] * 3 [[], [], []] I want to append an integer to the first sublist: some_lists[0].append(1) But it appends the integer 1 to all the sublists and generates: [[1], [1], [1]] How do I append elements individually to the sublists?
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I needed to create a list of lists in Python, so I typed the following: my_list = [[1] * 4] * 3 The list looked like this: [[1, 1, 1, 1], [1, 1, 1, 1], [1, 1, 1, 1]] Then I changed one of the innermost values: my_list[0][0] = 5 Now my list looks like this: [[5, 1, 1, 1], [5, 1, 1, 1], [5, 1, 1, 1]] which is not what I wanted or expected. Can someone please explain what's going on, and how to get around it?
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I'm trying to use a getter for an object, in order to store the information of that object in another object. Yet, just by using the getter, it immediately returns a NullPointerException. This is the code of the class that has the object as a field (and the getter): public class NodoAnos implements Serializable { private int ano; private NodoAnos proximo; private ListaEquipos equipos; public NodoAnos(int año) { this.ano = año; this.proximo = null; this.equipos = new ListaEquipos(); } public int getAno() { return ano; } public void setAno(int año) { this.ano = año; } public ListaEquipos getEquipos() { return equipos; } Here are all the methods before the NullPointerException (exception in code sample 6): Code Sample 1: private void informacion() throws IOException, FileNotFoundException, ClassNotFoundException { int ano = elegirAnoPopup(); //SEE CODE SAMPLE NUMBER 2 NodoAnos nodAno = new NodoAnos(ano); nodAno = anos.buscarAños(nodAno); //SEE CODE SAMPLE NUMBER 5 datosComboBoxUniversidad(nodAno); //SEE CODE SAMPLE NUMBER 6 } Code Sample 2: private int elegirAnoPopup() throws IOException, FileNotFoundException, ClassNotFoundException { NodoAnos aux = new NodoAnos(1); List<String> choices = new ArrayList<>(); anos = anos.leerArchivo(anos); //SEE CODE SAMPLE NUMBER 3 while(aux != null) { aux = anos.llenarDialogo(aux); //SEE CODE SAMPLE NUMBER 4 if(aux != null) choices.add(Integer.toString(aux.getAno())); } ChoiceDialog<String> dialog = new ChoiceDialog<>("Elegir año",choices); dialog.setTitle("Consultar Informacion"); dialog.setHeaderText("Por favor, introduzca la informacion requerida"); dialog.setContentText("Introduzca el año a consultar:"); Optional<String> result = dialog.showAndWait(); return Integer.parseInt(result.get()); } Code Sample 3: public ListaAnos leerArchivo(ListaAnos anos) throws FileNotFoundException, IOException, ClassNotFoundException { ListaAnos lista = anos; try { FileInputStream fis = new FileInputStream("lista.DAT"); ObjectInputStream ois = new ObjectInputStream(fis); if(ois != null) { ListaAnos objeto = (ListaAnos) ois.readObject(); lista = objeto; ois.close(); } } catch(FileNotFoundException e) { System.out.println("No existe un archivo"); } return lista; } Code Sample 4: public NodoAnos llenarDialogo(NodoAnos aux) { if(aux.getAno() == 1) aux = cabeza; else aux = aux.getProximo(); return aux; } Code Sample 5: public NodoAnos buscarAños(NodoAnos nodAño) { NodoAnos aux = cabeza; while(aux != null) { if( nodAño.getAno() == aux.getAno() ) { return aux; } else { aux = aux.getProximo(); } } return null; } Code Sample Number 6: private void datosComboBoxUniversidad(NodoAnos nodAno) { ListaEquipos listaEquipo = new ListaEquipos(); NodoEquipos nodEquipo = new NodoEquipos(null, 0, 0); listaEquipo = nodAno.getEquipos(); //NULLPOINTEREXCEPTION while(nodEquipo != null) { nodEquipo = listaEquipo.buscarEquipos(nodEquipo); if(nodEquipo != null) { comboUniversidad.getItems().add(nodEquipo.getUniversidad()); } } } IMPORTANT NOTE: nodAno is not Null. Already made sure of it. it prints as follows: torneodetenis.NodoAnos@12539123
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What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them? What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?
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I have a 160 mm water pipe at 5 bar pressure.What is the flow in litres per sec? I want to fit a hydro turbine to the outlet.
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Anybody kindly help me to find how to calculate pressure in bar from flow rate. I have a pipe and from that I am transferring water at a constant flow rate of 5ml/min. At this flow rate, with a 0.5 cm diameter pipe, what will be the pressure generated by water?
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I want to align super and subscript in the display and inline equations It should be: Now: There are n-number of occurrences in my manuscript, is there any possibility to achieve by a single move. MWE: \documentclass{article} \begin{document} $${_{gij}^{bj}\textbf{\textit{R}}}$$ \end{document}
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I am trying to put two subscripts at the left and right of a character. For example, something like: _{t} p_{x} where p is in the middle. How do you do this?
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I made a simple C program to get a float as input from the user using scanf() function and dispay it using printf() function. But when the input number is quite large, the output deviates slightly. Why might that happen? For example: if I give input as 2345, out put will be as expected. But if I give the output as 1234567898, the output will be unexpected. #include <stdio.h> int main() { float number; scanf("%f", &number); printf("The number %f", number); return 0; }
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double r = 11.631; double theta = 21.4; In the debugger, these are shown as 11.631000000000000 and 21.399999618530273. How can I avoid this?
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I fixed the malformed line error in my sources list, and was able to run the sudo apt-get update and sudo apt-get upgrade. When I ran the update these errors came up: W: Failed to fetch http://dl.google.com/linux/chrome/deb/dists/stable/Release Unable to find expected entry 'main/binary-i386/Packages' in Release file (Wrong sources.list entry or malformed file) W: Failed to fetch http://archive.getdeb.net/ubuntu/dists/trusty-getdeb/apps/binary-amd64/Packages 403 Forbidden W: Failed to fetch http://archive.getdeb.net/ubuntu/dists/trusty-getdeb/apps/binary-i386/Packages 403 Forbidden E: Some index files failed to download. They have been ignored, or old ones used instead. What should I do? Then, when I ran the upgrade, these errors showed up: The following packages were automatically installed and are no longer required: account-plugin-windows-live libnvpair1 libupstart1 libuutil1 libzfs2 libzpool2 thunderbird-locale-en thunderbird-locale-en-gb thunderbird-locale-en-us Use 'apt-get autoremove' to remove them. The following packages have been kept back: cups-filters cups-filters-core-drivers grub-common grub-efi-amd64 grub-efi-amd64-bin grub-efi-amd64-signed grub2-common libldb1 liboxideqt-qmlplugin liboxideqtcore0 liboxideqtquick0 libsmbclient libwbclient0 linux-headers-generic linux-headers-lowlatency linux-image-lowlatency linux-lowlatency linux-signed-generic linux-signed-image-generic openjdk-7-jre openjdk-7-jre-headless oxideqt-codecs-extra python-cupshelpers python-ldb python-samba qpdf samba samba-common samba-common-bin samba-dsdb-modules samba-libs samba-vfs-modules shim shim-signed smbclient system-config-printer-gnome ubuntu-minimal winbind 0 upgraded, 0 newly installed, 0 to remove and 38 not upgraded. W: Duplicate sources.list entry http://dl.google.com/linux/chrome/deb/ stable/main amd64 Packages (/var/lib/apt/lists/dl.google.com_linux_chrome_deb_dists_stable_main_binary-amd64_Packages) W: Duplicate sources.list entry http://dl.google.com/linux/chrome/deb/ stable/main amd64 Packages (/var/lib/apt/lists/dl.google.com_linux_chrome_deb_dists_stable_main_binary-amd64_Packages) W: You may want to run apt-get update to correct these problems What should I do? Thanks!
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I'm trying to install programs/files from the getdeb repo but get a "check your internet connection" error. Programs than I've tried include Qbittorrent and Mozilla-Plugin-VLC. Through the terminal I get the following errors: Err http://archive.getdeb.net/ubuntu/ natty-getdeb/apps qbittorrent amd64 2.8.2-1~getdeb2 Could not connect to archive.getdeb.net:80 (209.105.191.78). - connect (113: No route to host) E: Failed to fetch http://archive.getdeb.net/ubuntu/pool/apps/q/qbittorrent/qbittorrent_2.8.2-1~getdeb2_amd64.deb: Could not connect to archive.getdeb.net:80 (209.105.191.78). - connect (113: No route to host) & Err http://archive.getdeb.net/ubuntu/ natty-getdeb/apps mozilla-plugin-vlc amd64 1.1.10-1~getdeb1 Could not connect to archive.getdeb.net:80 (209.105.191.78). - connect (113: No route to host) E: Failed to fetch http://archive.getdeb.net/ubuntu/pool/apps/v/vlc/mozilla-plugin-vlc_1.1.10-1~getdeb1_amd64.deb: Could not connect to archive.getdeb.net:80 (209.105.191.78). - connect (113: No route to host) I'm not having any problems adding/removing other programs/files from my machine. Is there a problem with GETDEB repo (and if so, is there any way to fix it on my end) or is there something wrong with my computer's configuration?
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I need to force any time related operations to GMT/UTC, regardless the timezone set on the machine. Any convenient way to so in code? To clarify, I'm using the DB server time for all operations, but it comes out formatted according to local timezone. Thanks!
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When I create a new Date object, it is initialized to the current time but in the local timezone. How can I get the current date and time in GMT?
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So I've been going in circles over the last few hours of this seemingly simple problem: "Let $(X,F,\mu)$ be a probability space. Let $A,B,C$ be sets contained in $F$, with $\mu(A \cap B) \ge \frac{1}{2}$, $\mu(A \cap C) \ge \frac{1}{2}$, $\mu(B \cap C) \ge \frac{1}{2}$. Show that $\frac{1}{4} \le \mu(A \cap B \cap C) \le \min\{\mu(A \cap B), \mu(A \cap C), \mu(B \cap C)\}$". Honestly, I'm plain simply stuck. I've been trying to see if I could get something useful out of De Morgan's identities as well as the distributive laws, but I seem to either be going in circles or end up with something not very useful due to unions I can not identify or the lack of information about $A$, $B$ and $C$. Same thing with the strongly additive property of a measure, which is only stated for the intersection of two sets in my book. I feel like this should be simple, but I'm staring myself blind at this problem. Can anyone offer some guidance?
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Let $\{X,\mathcal{A},\mu\}$ be a probability space. Let $A$, $B$, $C$ be sets in $\mathcal{A}$, which satisfy $$\mu (A\cap B)\geq \frac{1}{2}, \quad \mu (A\cap C)\geq \frac{1}{2}, \quad \mu (B\cap C)\geq \frac{1}{2}.$$ Show that $\frac{1}{4}\leq \mu(A\cap B \cap C)$. I've managed to show in a previous assignment that $$\mu(A\cap B \cap C)\leq \min\{\mu (A\cap B), \mu (A\cap C), \mu (B\cap C)\},$$ but now I'm stuck with the above inequality. I've tried to draw it, but still no luck. Any hints?
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I purchased a new VPS from bluehost they provided me old version of PHP that's not supporting my website and Its been 1 Week bluehost technical support team refused to do that they are making excuses. My ubuntu version is 12.04.5 LTS I want to update Apache,MySQL and PHP with their latest version and all dependencies and necessary extensions that are commonly used on website. I know that some people think that my Question is duplicate of other questions. I am asking that what I have to do for upgrading Apache, MySQL and PHP for example: I have to remove all these three before upgrading on server ? My problem is how can i upgrade Apache, MySQL and PHP??? Please explain step by step
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I am trying to update to install PHP 5.5, 5.6 or 7.0 in Ubuntu 12.04/14.04/16.04 LTS, and I can only get PHP 5.3.10 for Ubuntu 12.04, PHP 5.5.9 for Ubuntu 14.04 or PHP 7.0.4 for Ubuntu 16.04 using official repositories (using apt-get). I'm not really sure how to do a manual update – as I need: to play around with the new(est) PHP features to install older PHP version due support in the software
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If we can shield a charge from electrical forces by putting it inside a hollow conductor. Can we shield a body from gravitational influence of nearby matter by putting it inside a hollow sphere or by some other means ?
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Electromagnetic waves can be shielded by a perfect conductor. What about gravitational fields or waves?
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I'm trying to write a code to find a simple path between (0,0) and (n,n) of a matrix and I'm using stacks to keep previously visited x's and y's but I'm getting "java.lang.NullPointerException" at line 28 when I'm trying to push a Pair to the stack. I've tried using .add from vectors but it also didn't help import java.util.Arrays; import java.util.Random; import java.util.Stack; public class MatrixPathfinder { static class Pair { private int x; private int y; public Pair(int x, int y) { this.x = x; this.y = y; } public int getX() { return x; } public int getY() { return y; } } public static boolean hasPath(int[][] arr, int[][] visited, Stack<String> path, Stack<Pair> stack, int i, int j) { int rowLength = arr.length; int columnLength = arr[0].length; //if it's the last element, output the path if(i == rowLength - 1 && j == columnLength - 1) { System.out.println(path); return true; } stack.push(new Pair(i,j)); //Go right if path available if(i >= 0 && i < rowLength && j + 1 >= 0 && j + 1 < columnLength && arr[i][j+1] != 0 && visited[i][j + 1] != 1) { path.push("R"); visited[i][j + 1] = 1; hasPath(arr, visited, path, stack, i, j + 1); } //Go down if path available else if(i + 1 >= 0 && i + 1 < rowLength && j >= 0 && j < columnLength && arr[i+1][j] != 0 && visited[i + 1][j] != 1) { path.push("D"); visited[i + 1][j] = 1; hasPath(arr, visited, path, stack, i + 1, j); } //if non above satisfied, go back previous point to find another direction else { if(stack.size() == 0) return false; path.pop(); i = stack.peek().getX(); j = stack.peek().getY(); stack.pop(); hasPath(arr, visited, path, stack, i, j); } } public static void main(String[] args) { Stack<Pair> stack = null; Stack<String> path = null; Random random = new Random(); int[][] visited = new int [5][5]; int[][] arr = new int[5][5]; for (int[] row : visited) { Arrays.fill(row, -1); } for (int i = 0; i < 5; i++) { for (int j = 0; j < 5; j++) { arr[i][j] = random.nextInt(2); } } //making sure the starting and destination points are valid path points arr[0][0] = 1; arr[3][3] = 1; visited[0][0] = 1; if (hasPath(arr, visited,path, stack,0 ,0)) System.out.printf("Path found"); else System.out.println("Path not found"); } }
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What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them? What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?
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If $a, b>0$ and n is a positive integer, prove that: $(1+\frac{a}{b})^n+(1+\frac{b}{a})^n\ge 2^{n+1}$ I solved it in the following way: $(1+\frac{a}{b})^n+(1+\frac{b}{a})^n \ge (2\sqrt{\frac{a}{b}})^n+(2\sqrt{\frac{b}{a}})^n=2^n((\frac{a}{b})^n+(\frac{b}{a})^n)$ It is enough if $(\sqrt{\frac{a}{b}})^n+(\sqrt{\frac{b}{a}})^n\ge2$ If $n=1$: $\sqrt{\frac{a}{b}}+\sqrt{\frac{b}{a}}\ge2$ $\frac{a}{b}+\frac{b}{a}+2\ge 4$ which holds true. If it holds true for $n=k$: If $b\ge a$: $(\sqrt{\frac{a}{b}})^k+(\sqrt{\frac{b}{a}})^k$ $(\sqrt{\frac{a}{b}})^{k+1}+\sqrt{\frac{a}{b}}*(\sqrt{\frac{b}{a}})^k\ge 2$ $(\sqrt{\frac{a}{b}})^{k+1}+(\sqrt{\frac{b}{a}})^{k-1}\ge 2$ And since $b\ge a$ We have that the original proposition holds true for k+1. Similarly, we prove that it is true if $a\ge b$. Hence because of induction, it holds true. Could you please show some other methods of solving this question easier?
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Let $a$ and $b$ be positive real numbers and let $n$ be a natural number prove that $$\left({1+\frac ab}\right)^n+\left(1+\frac ba\right)^n\ge2^{n+1}.$$
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I'm following blog post to add this feature onto my app where I can take a picture then save the picture data as a Uri for further functions. But I'm getting an error when I try to open the camera intent. java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.XmlResourceParser android.content.pm.ProviderInfo.loadXmlMetaData(android.content.pm.PackageManager, java.lang.String)' on a null object reference I suspect there is something wrong with the file_paths.xml but I double checked there is nothing wrong. I've done some research on different ways of saving images through like FileProvider but most of it doesn't work for me either. Does anyone know what's wrong with my code? MainActivity private void openCameraIntent() { Intent pictureIntent = new Intent( MediaStore.ACTION_IMAGE_CAPTURE); if(pictureIntent.resolveActivity(getPackageManager()) != null){ //Create a file to store the image File photoFile = null; try { photoFile = createImageFile(); } catch (IOException ex) { // Error occurred while creating the File } if (photoFile != null) { Uri photoURI = FileProvider.getUriForFile(this, com.example.camerapplication.provider", photoFile); pictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI); startActivityForResult(pictureIntent, REQUEST_CAPTURE_IMAGE); } } } @Override protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) { if(requestCode == REQUEST_CAPTURE_IMAGE && resultCode == RESULT_OK){ Glide.with(this).load(imageFilePath).into(image); // TODO:Use Image Uri for further functions } } private File createImageFile() throws IOException{ String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss", Locale.getDefault()).format(new Date()); String imageFileName = "IMG_" + timeStamp + "_"; File storageDir = getExternalFilesDir(Environment.DIRECTORY_PICTURES); File image = File.createTempFile(imageFileName,".jpg",storageDir); imageFilePath = image.getAbsolutePath(); return image; } Manifest <uses-feature android:name="android.hardware.camera" android:required="true" /> // ... Other elements and then // Within application scope <provider android:name="androidx.core.content.FileProvider" android:authorities="${applicationId}.provider" android:exported="false" android:grantUriPermissions="true"> <meta-data android:name="android.support.FILE_PROVIDER_PATHS" android:resource="@xml/file_paths"> </meta-data> </provider> file_paths.xml <?xml version="1.0" encoding="utf-8"?> <paths xmlns:android="http://schemas.android.com/apk/res/android"> <external-path name="my_images" path="Android/data/com.example.cameraapplication/files/Pictures" /> </paths> EDITED changed to proper path="Android/data/com.example.cameraapplication/files/Pictures"
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What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them? What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?
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During customization I want to add an image as the terminal background.
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Is there a way to give terminal specific background image and make it 50% transparent at the same time?
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Are there any different in using camera in manual mode vs aperture mode plus exposure compensation? This the same according to dynamic range or maybe something other difference?
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I'm wondering what are the most compelling reasons to switch to manual mode on my DSLR. I mostly just use aperture priority mode so I have good control over the depth of field combined with an awareness of the shutter speed that goes with it. My photography is mostly done wandering about with camera in hand, or occasionally on a tripod. I don't do studio photography and I just use the natural light. I did learn how to take photos manually (with an Olympus OM-1) so I know how to do it, but I enjoy the extra convenience of aperture mode, particularly being able to take the photo quickly and capturing the moment rather than fiddling with dials and missing the shot. So what would be some key advantages of using manual mode for my sort of photography that are worth the (small amount of) extra hassle involved? And do you have any tips to minimise the downside (other than practicing to be quick)?
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How prove that for every convex polygon there exist three consecutive vertices which their circumcircle include all poligon?
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Given a convex $n$-gon. The circumcircle is constructed for every triple of consecutive vertices of the polygon. We get the $n$ circles. Select the circle with the largest radius. Prove that the circle contains the polygon. My work so far: $n=3 -$ triangle - obviously. $n=4 -$ If $\angle B = \max \left\{A,B,C,D \right\}$ then $ABCD \in \omega_{ABC}$ $n\ge 5$. I need help here.
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I'm not sure how this happened, but my /tmp directory is on a separate partition called "overflow" with only 1.1M allocated to it, which is 100%. This is preventing me from doing almost anything, including installing packages. The server is Ubuntu 14.04 running on EC2. I recently increased the size of it's disk from 20G to 200G and rebooted the instance, and now df -H shows: Filesystem Size Used Avail Use% Mounted on udev 2.1G 8.2k 2.1G 1% /dev tmpfs 415M 390k 415M 1% /run /dev/xvda1 529G 39G 469G 8% / none 4.1k 0 4.1k 0% /sys/fs/cgroup none 5.3M 0 5.3M 0% /run/lock none 2.1G 0 2.1G 0% /run/shm none 105M 0 105M 0% /run/user overflow 1.1M 1.1M 0 100% /tmp What is this "overflow" filesystem and how do I get /tmp off of it?
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I'm not able to run update manager as I get an error saying that there is not enough free space in the /tmp directory. I've practically cleaned out the tmp directory but the error persists. here's df-h /dev/loop0 13G 11G 952M 92% / udev 2.0G 4.0K 2.0G 1% /dev tmpfs 785M 920K 784M 1% /run none 5.0M 0 5.0M 0% /run/lock none 2.0G 584K 2.0G 1% /run/shm /dev/sda6 20G 14G 6.4G 68% /host overflow 1.0M 16K 1008K 2% /tmp
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I know this is a big question. But as a graduate student, my research is somehow related to nonequilibrium thermodynamics/statistical mechanics. TBH, I hate how some research treat this subject like a mystery and use some theories carelessly. So I want to learn the subject at my own pace. I have finished Fermi Enrico's "thermodynamics" for a start. And I'm reading Terrell Hill's "introduction to statistical thermodynamics." Although I am pretty satisfied with the content of these two books, I have no idea where should I go from here. Because I expect my future research will still be based on nonequilibrium thermo/stat mech, I need a booklist to guide me from "knowing something" to "knowing something advanced." In the meantime, I hope I can equip myself with advanced mathematics by going through the booklist. Can anyone provide some ideas on this? Thanks for the reminder from Endulum. To be more precise, my research interests include the particle diffusion in crystal materials and phase transition. And I also expect to do some research in the future about the transport of heat and charged species in the liquid or solid phase. P.S., I am not looking for working understanding of this subject. A solid but accessible booklist would be perfect.
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What is a good textbook on statistical field theory, with an emphasis on applications to non-equilibrium phenomena? I am a final-year undergraduate, have already taken introductory classes in statistical physics and quantum mechanics but do not know a lot of quantum field theory yet. I would like to better understand nonequilibrium phenomena, phase transitions and spontaneous symmetry breaking in condensed matter systems.
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I'm trying to figure out how to calculate the power series for exp(exp(x)) using exp(x) and then to write down the first few terms. I have the answer for the terms but I don't know how they arrived at it Thanks in advance For the first few terms we have: exp(exp(x)) = e(1 + x + x^2 + . . .)
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I need to find terms up to degree $5$ of $e^{e^{z}}$ at $z=0$. I tried letting $\omega = e^{z} \approx 1+z+\frac{z^{2}}{2!}+\frac{z^{3}}{3!}+\cdots$, and then substituting these first few terms into the Taylor series expansion for $e^{z}$ as follows: $e^{\omega} = \sum_{n=0}^{\infty}\frac{\omega^{n}}{n!} = 1 + \omega + \frac{\omega^{2}}{2!}+\frac{\omega^{3}}{3!}+\cdots = 1 + (1+z+\frac{z^{2}}{2!}+\frac{z^{3}}{3!}+\frac{z^{4}}{4!}+\cdots) + \frac{1}{2}\left(1+z+\frac{z^{2}}{2!}+\frac{z^{3}}{3!}+\frac{z^{4}}{4!}+\cdots \right)^{2}+ \frac{1}{3!}\left( 1+z+\frac{z^{2}}{2!}+\frac{z^{3}}{3!}+\frac{z^{4}}{4!}+\cdots\right)^{3}+\cdots$ But, then when I try to multiply this all out (using Maple), I find that going even further out than I have here, the terms of degree $\leq 5$ do not terminate. So, then I tried putting the command into Maple, and it came out to be something long and horrible with $e$ coefficients for each term. I must be missing something here. Could somebody please tell me how to finish this problem? I would ask for a complete solution, not hints or leading questions. I've been working on this for hours and am beyond frustrated. The most edifying thing for me at this point would be to see the correct, full way it's supposed to be done, work backwards, take it apart, and then be able to apply it to other situations. Thank you.
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I need to find out the last update time (or last changed time) of a table in the database (i.e. the last time when data in a specific table is updated, deleted or inserted) for deciding whether a backup is needed or not. As per the MySQL/MariaDB manual, I have used the following SQL statement to get the last modified time of a table in the database: SELECT update_time FROM information_schema.tables WHERE table_schema='my_db' and table_name='my_table'; -- For table named 'my_table' in database 'my_db' Here's the problem: The value of the resultant update_time field is always returned NULL even though changes are made in the specified table. What's more unanticipated is that when I manually browse the tables table in the information_schema database, there are no entry of my_db and my_table in table_schema and table_name fields respectively, meaning that the activities are not logged. Can someone please help me solve this problem and explain me the reason behind it? EDIT: This question is not a duplicate as the question also asks about the fields of information_schema.tables being NULL rather than just asking how to get last update time.
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In the footer of my page, I would like to add something like "last updated the xx/xx/200x" with this date being the last time a certain mySQL table has been updated. What is the best way to do that? Is there a function to retrieve the last updated date? Should I access to the database every time I need this value?
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I analyse an interview transcript and would like to add plenty of notes in the margin. Sometimes these margin notes will not fit on the current page, and thus I would like them to flow to the next page. The marginfix package is supposed to fix this, but obviosly I have too many marginpars and LaTeX runs out of memory ("LaTeX Error: Too many unprocessed floats."). I have now searched StackExchange (and Google) in vain; thus I ask the masterminds of LaTeX if a solution is possible?
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I want to create a problem booklet consisting of some questions and images on the marginpar. How to make sure the images properly float on the marginpar? If you carefully see the left image below, you will notice that the most bottom image gets cropped as it is not properly floated. \documentclass[twoside,12pt]{book} \usepackage[ a4paper, vmargin=2cm, outermargin=9cm, innermargin=2cm, marginparwidth=7cm, marginparsep=20pt ]{geometry} \usepackage{graphicx} \usepackage{marginnote} \usepackage{caption} \usepackage{lipsum} \newcommand\MarginFig[1]{% \marginpar{\includegraphics[width=\marginparwidth]{example-image-a} \captionof{figure}{#1} \label{#1}}} \begin{document} \chapter{Higgs Boson} \lipsum[1-3] \begin{enumerate} \item \MarginFig{1} \MarginFig{2} \MarginFig{3} \lipsum[1-2] \item \MarginFig{4} \MarginFig{5} \MarginFig{6} \lipsum[1-2] \item \MarginFig{7} \MarginFig{8} \MarginFig{9} \lipsum[1-2] \end{enumerate} \end{document} This question is a continuation of . Edit 3 Bonus questions (without prizes): Among the permutation of \MarginFig{n}, \MarginFig{n+1}, \MarginFig{n+2}, and \lipsum[1-2], which one will produce the best floating?
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I have a Power Supply of 24 volts and 2.5A. I need something like that: I need a power supply of 24V and almost 1500mA and another of around 8 volts and 500mA (to suplpy an Arduino). It is possible with this connection? Or I nees something like How much the resistors would be? Thanks!
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When would you use a voltage regulator vs a resistor voltage divider? Are there any uses for which a resistor divider is particularly bad?
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recently I switched from zorin os to deepin 20 for it's outstanding UI and eases of use for daily operations. it's almost OK but if I need some newer packages which are not listed in official deepin repositories, I have to use some community installer scripts that rely on this command to obtain the correct linux LSB version : lsb_release -c the problem is : the return value is "n/a" that consequently, breaks down the installation process. how can I fix this ?
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I am trying to create a script that requires me to print the debian codename so that I may echo it into the sources.list file. I am trying to make this script work across any version of Debian, so I had hoped to set a bash variable of the release codename. This would be simple to do (with lsb_release -c), however our deployment images do not contain lsb_release by default - and with this script being required to fix the sources.list, installing lsb-release with apt-get would not be an option. I have found numerous ways to get the release number and other info about the system, but cannot find a reliable place to get the codename. Any ideas would be greatly appreciated! (OS I am testing this with is Debian Squeeze)
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I have a question. I must prove with induction that $$\displaystyle 2^{2n+1} - 9n^{2} + 3n - 2$$ is divisible by $54$. My attempt was that if I plug in $n = 0$, I get result of $0$. Then I want to show this sentence for $n + 1$: $2^{2(n+1) + 1} - 9(n + 1)^2 + 3(n + 1) - 2 = 2^{2n + 3} - 9n^2 - 18n - 9 + 3n + 3 - 2 = (2^{2n + 1} \cdot 4 - 9n^2 + 3n - 2 ) - 18n - 6 = (3 \cdot 2^{2n + 1} - 18n - 6) + \left(2^{2n + 1} - 9n^{2} + 3n - 2\right)$. Here I stopped, because I don't know how to manipulate the prove. Can anyone help me?
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What I get is $4 \cdot 54k + 27(n(n-1)) - 2$. I understand first two terms but $-2$ is giving me a headache. I suppose to be true every term should be divisible by $54$. Or did I make wrong conclusion? P. S: Is there mathjax tutorial?
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Automator Shell Script echo $PATH eval /usr/libexec/path_helper -s echo $PATH Results: after the first echo $PATH: /usr/bin:/bin:/usr/sbin:/sbin after the second echo $PATH: /usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin As ImageMagick is installed in /usr/local/bin it means that it fails unless I mess with the PATH first anyone know where Automator (Java is the same) gets its path from and how to permanently add the missing paths
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I'm making an Automator workflow that uses the shell script action to process a selection of images with the imagemagick composite command. Only I'm having issues getting it going. According to the results I get when I run the workflow, everything is working however, I know it's not due to the fact that the changes I'd expect to see in the folder of images are not present. I know that the imagemagick command I'm using is correct as it works correctly from the console. (I echoed the composite command to the output & copied it into a Terminal session. Ran like a charm). BTW: The workflow's for processing a fade in on a stop motion movie I made. Yes I know I could use video tools to achieve the same thing, but the ones I have access to screw up the image quality on output. Here's the script imagesCount=$# rate=$(echo "scale=2; 100/$imagesCount"|bc) percentage=$rate for f in "$@"; do fileName=${f%.*} composite -blend "$percentage" -size 1280x720 "$f" xc:black -alpha Set "$fileName-1.jpg" percentage=$(echo "scale=2; $percentage+$rate"|bc) done At first I thought at the cause of the problem might be spaces in the paths, but I removed this possibility by shifting the files to a path without spaces, but that had no effect. I'm almost certain the issue is related to something in the bash command but I don't know bash at all, this is my first time writing any bash command scripts, but I am very knowledgeable in Windows console scripting and would have no trouble getting this to work there. If the error in the script isn't obvious enough to catch, would someone propose a method to debug this so I can figure out why the images are not getting processed even though the script runs without error?
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I've encrypted my sd csrd on my old phone. This has since broken and wont turn on. I upgraded to a samsung s9 and put my sd card in. It wont let me decrypt the sd cre through any password or pin an tells me to decrypt it on my old phone first before being able to use it on my new phone. Help please
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I have a Samsung Galaxy S5 duos with stock Android Marshmallow, and I'm considering encrypting my SD card to prevent access to its contents in case I lose my phone. The main reason of not doing this is that I'm not sure if there's a way to mount an encrypted SD card on Windows (or other desktop OS's) When I encrypt the SD card on my Samsung Galaxy S5, is it using a known implementation of encryption, or is it something that only works on Android (or perhaps Samsung) phones? I do not want to use USB connection to my phone to access my SD card, it's terrible. Mounting the SD card is much easier and faster and less annoying. EDIT: just to clarify, I am NOT talking about adoptable storage. I want a portable encrypted SD card that can both be read on PCs and Android phones (i.e. I want to be able to remove the SD card from my phone, plug it into my PC, provide a password to decrypt and read/write it like any other SD card)
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I am trying to solve the following problem: Show that the trace functional on $n \times n$ matrices is unique in the following sense. If $W$ is the space of $n \times n$ matrices over the field $F$ and if $f$ is a linear functional on $W$ such that $f(AB)=f(BA)$ for each $A$ and $B$ in $W$, then $f$ is a scalar multiple of the trace function. I know that one way to prove this is to show that the null space of $f$ equals the null space of the trace function, but I found this solution rather complicated; any other suggestions?
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We know that the trace of a matrix is a linear map for all square matrices and that $\operatorname{trace}(AB)=\operatorname{trace}(BA)$ when the multiplication makes sense. On the , under properties, it says that these properties characterize the trace completely in the following sense: If $f$ is a linear function on the space of square matrices satisfying $f(xy)=f(yx)$, then $f$ and $\operatorname{tr}$ are proportional. A of the page gives the justification, but I do not understand the logic of it. Thanks
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When I go into camera view, part of my scene gets cut off automatically. The render tab and shading tab also has part of my scene not visible but the scene is fine in all other modes.
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I have created a simple model here When rendering it the end of it is cut off How can I get the camera to render a longer distance?
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Possible to construct a disjoint sequence of infinite subsets of $\mathbb{N}$ whose union is not $\mathbb{N}$? I am thinking this must be possible. I've considered trying to define each sequence as the range of some function. I have to find a way to hop over natural numbers in some way to leave infinitely many left for each subsequent subset of $\mathbb{N}$. Thinking about just leaving out $1$ so then the union isn't $\mathbb{N}$. I haven't tried to do anything like this before. Any possible hints on how this can be done and I can think a little more to see if I can come up with something? If not I may just ask for an answer heh. Thanks much for your time and input I appreciate it very much.
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The title says it. I thought of the following: we want $$\Bbb N = \dot {\bigcup_{n \geq 1} }A_n$$ We pick multiples of primes. I'll add $1$ in the first subset. For each set, we take multiples of some prime, that hasn't appeared in any other set before. Then $$\begin{align} A_1 &= \{1, 2, 4, 6, 8, \cdots \} \\ A_2 &= \{3, 9, 15, 21, 27, \cdots \} \\ A_3 &= \{5, 25, 35, 55, \cdots \} \\ A_4 &= \{7, 49, 77, \cdots \} \\ &\vdots \end{align} $$ I'm heavily using the fact that there are infinite primes. I think these sets will do the job. Can someone check if this is really ok? Also, it would be nice to know how I could express my idea better, instead of that hand-waving. Alternate solutions are also welcome. Thank you! Edit: the subsets must be also infinite.
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given the next code: class A { // ... }; class B : public A { // ... }; And: A a; B b; A& ab = b; ab = a; Will be a slicing in the last line of this code? Why?
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Someone mentioned it in the IRC as the slicing problem.
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I'm trying to test some data for the best distribution fit, and am looking to try the t-dist (all theoretically, no R computations) I think the best way to do this is to assume the distribution is true, use MLE or MoM to estimate parameters and then conduct a goodness-of-fit test. Firstly, is this an appropriate way to do it? Secondly, what is the theoretical derivation for the parameters of the t-dist (using MLE or Mom) And thirdly, how do you estimate the degrees of freedom for a t-test? Thanks
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What are the maximum-likelihood estimators for the parameters of Student's t-distribution? Do they exist in closed form? A quick Google search didn't give me any results. Today I am interested in the univariate case, but probably I will have to extend the model to multiple dimensions. EDIT: I am actually mostly interested in the location and scale parameters. For now I can assume that the degrees of freedom parameter is fixed, and possibly use some numeric scheme to find the optimal value later.
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I have the following task: Prove that if $ f : I \rightarrow \mathbb{R} $ is continuous ($ I $ is a range) and $$ \forall {x,y \in I} \qquad f\left(\frac{x+y}{2}\right) \leq \frac{f(x) + f(y)}{2} $$ then $f$ is a convex function. Can somebody give a hint what can I use to prove this? This is a homework assignment, so I'd like to try solve it myself.
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Given that $$f\left(\frac{x+y}{2}\right)\leqslant \frac{f(x)+f(y)}{2}~,$$ how can I show that $f$ is convex. Thanks. Edit: I'm sorry for all the confusion. $f$ is assumed to be continuous on an interval $(a,b)$.
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I'm not a mathematician just an ordinary person, I would like to know, what is the mathematical chance for this to happen: A computer randomly chose 1 number out of 1024, how many times you need to try to find the number? After each unsuccessful try the computer will randomly chose another number out of 1024 which you have to guess and so on until you find the right number. Thanks
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Is there anything that can be said about how many attempts it will take to correctly guess a random number out of 1000 numbers? If the number wouldn't change the probability would just increase every guess, giving in the end a probability of 1. If the number changes every guess tough, you just have a 1/1000th chance everytime. Can it be calculated how many attempts it would probably take, on average? (I'm sorry, i'm not very skilled in probability maths)
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In the literature on point particles in 2+1 gravity, I often see the identity $$d^2 \phi = 2\pi \delta^{(2)}(r)dx\wedge dy$$ being used. Here, the particle is a puncture located at the origin and $(r,\phi)$ are polar coordinates around this puncture. One example is in (unfortunately it's behind a paywall), where in equation 3.4 the author uses the above identity to show that the torsion and curvature are both described by delta distributions. For example, for the curvature, since the connection is given in equation 3.3b by $\omega=M d\phi$, the curvature is $$F=d\omega=Md^2\phi=2\pi M \delta^{(2)}(r)dx\wedge dy.$$ Other papers seem to be using this result as well, and cite the above paper. One example is , equations 4.6-4.7. I know that $d^2$ is supposed to be always zero because the partial derivatives commute, so this has to fail somehow for the identity to be satisfied, but I don't know how that would happen in this case.
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So I know Stokes theorem for integrating exact differential forms over a chain: $$\int_cd\omega=\int_{\partial c}\omega.$$ But what if there are holes? More precisely, consider the following famous example: Consider the punctured plane $U=\Bbb R^2\setminus\{(0,0)\}$ and the differential form $$\omega=\frac{1}{x^2+y^2}(-ydx+xdy)$$ on $U$. It is known that line integral of $\omega$ along a circle $c:[0,1]\to U, c(t)=(\cos 2\pi t,\sin 2\pi t)$, is $2\pi$. Stokes theorem does not really apply here because neither is $\omega$ exact nor is $c$ the boundary of another chain. But it is possible to "define" the following (I saw similar things from physics textbook and notes):$$d\omega=2\pi\delta(x,y)dx\wedge dy$$where $\delta$ is the Dirac delta function, giving infinity when $x=y=0$, and $0$ otherwise, such that the integral of $\delta(x,y)dx\wedge dy$ over a subset $S$ of $\Bbb R^2$ is $1$ if the origin is an interior point of $S$. Regard $c$ as the boundary of the unit disk $D$ at the origin and Stokes theorem can be "applied" just fine, by$$\int_Dd\omega=\int_{c}\omega.$$ Is there a way to formalise these ideas? If possible, I would like to see some reference to formal definitions of such generalised exterior derivative and proofs of such generalised Stokes theorem. I know some complex analysis (Cauchy's integral formula), the definition of a , and the definition of de Rham cohomology if it will help.
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I'm currently learning about hyperbolic trig functions, and i don't really get the point. At first, I found it really weird that the input is the area divided by 2, and just wondered what was the point of it anyways? So, are there any real world applications for this kind of stuff?
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I covered hyperbolic trigonometric functions in a recent maths course. However I was never presented with any reasons as to why (or even if) they are useful. Is there any good examples of their uses outside academia?
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less and more seem to have very similar functionality in that they both page through text a screen at a time. What reasons are there to use one over the other?
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When I do more filename and less filename, it would seem that the resulting terminals are quite similar. I can navigate and search through my files identically (j, Space, /pattern, etc.). I find it hard to believe that less is more and vice versa. Are there any differences between the two?
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Does there exist an integer $x$ satisfying the following congruence: $10x=1\mod 21$ $5x=1\mod 6$ $4x=1\mod 7$ My try: Using Chinese Remainder Theorem: $n=n_1*n_2*n_3=21*6*7=882$ . Then consider $n_1^{'}=42,n_2^{'}=147,n_3^{'}=126$. Consider $n_1^{'}x \equiv 1\mod n_1$,$n_2^{'}x \equiv 1\mod n_2$,$n_3^{'}x \equiv 1\mod n_3$ . Substituting we get $42x\equiv 1\mod(21)$,$147x\equiv 1\mod(6)$,$126x\equiv 1\mod(7)$ But $42x\equiv 1\mod(21)$, is never true as $21*2=42$ Thus no such solution exists. Is this true?
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Does there exist an integer $x$ satisfying the following congruences? $$10x = 1 \pmod {21} \\ 5x = 2 \pmod 6 \\ 4x = 1 \pmod 7$$ I was trying to do this by following way but failed to get an answer:- At first rewrite the equation as: $$\begin{align}10x = 1 \pmod 3 \tag{1} \\ 10x = 1 \pmod 7 \tag{2} \\ 5x = 2 \pmod 2 \tag{3} \\ 5x = 2 \pmod 3 \tag{4} \\ 4x = 1 \pmod 7 \tag{5}\end{align}$$ But equation $(1)$ and $(4)$, and $(2)$ and $(5)$ are same. So it becomes as: $$10x = 1 \pmod 3 \\ 10x = 1 \pmod 7 \\ 5x = 2 \pmod 2$$ and now try to solve this by Chinese Remainder Theorem. But the answer does not satisfy. Is my process wrong?
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Is there a Stack Exchange site for book-specific questions (e.g., how does Harry Potter open the snitch in the 7th book)? Is/Should there be a community for this?
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Is there any Stack Exchange site where the main topic is literature? I have tried the English Language site, but it seems that it is not the appropriate site. Perhaps the writers site would work? But, then again, the main point is different than the one I am searching for.
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Most modern motorized vehicles are capable of both forward and reverse motion. In the Star Trek universe, can an unmodified warp drive also be used to move backwards? I realize that pretty much every ship we've seen has its navigational deflector (that is, the force field generator that pushes space dust and small debris away from the path of the ship) installed at the front of the vessel. But ; it doesn't make it impossible. Safety issues aside, is there any technical or engineering reason why warp drives cannot operate in reverse? If not, have we ever observed a ship warping backwards, perhaps to escape from a dire emergency? Or have we perhaps observed ships with an extra navigational deflector mounted on the rear? I'm interested primarily in the canonical TNG-era continuity (including the DS9 and Voyager series), with preference given to evidence from the shows and movies themselves, or alternatively to reliable print sources such as the show's Writers'/Directors' Guide and the Technical Manual. If this issue is absolutely never discussed in those sources, then an answer based on other Trek series/movies/continuities/canons would be acceptable.
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I've seen them maneuver. They definitely can go backwards. How fast can they go in reverse? Is warp speed possible, or is reverse limited to impulse power? If it is limited to impulse power, can they travel backwards under impulse power as fast as they travel forwards under impulse power?
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How can I get the mount point "3.1T" under the column " Avail" (using grep or cut)? Filesystem Size Used Avail Use% Mounted on vstorage://cluster07 4.0T 907G 3.1T 23% /vstorage/cluster07
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With the command of df, I can get something like: Filesystem 1K-blocks Used Available Use% Mounted on /dev/root 197844228 15578648 180242500 8% / devtmpfs 4101368 0 4101368 0% /dev tmpfs 820648 292 820356 1% /run tmpfs 5120 0 5120 0% /run/lock tmpfs 1693720 4 1693716 1% /run/shm What if I just want to keep the 180242500 number recorded of / and store it in a file (like disk-space-available.txt) If I use df >> disk-space-available.txt it will store all the content while I just want the raw number in that file. For example if there is something like this then it's working: df -OUTPUT=raw-available-number 180242500 What can I do?
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So this here questions got me stuck for a bit: Determine whether S is a subspace of V, if yes find a basis and its dimension. Let $S$ be the set of all 3x3 symmetric matrices in $V = M_{3x3}$ And here's why: I checked the appropriate axioms and it turns out S is in fact a subspace of V, but my main problem is that before this exercise, to find a basis, I'd find the augmented matrix and solve it (RREF) and then determine the solution, but here I'm not sure if I can. So I have an approach but not sure which if it works: If I say for e.g. Assume the matrix $A=\begin{pmatrix} a & b & c\\ b & d & e\\ c & e & f\\ \end{pmatrix}$ if det(A) $\neq 0$ => linearly independent => the basis exists. $k_1\begin{pmatrix} a\\ b\\ c\\ \end{pmatrix}$ + $k_2\begin{pmatrix} b\\ d\\ e\\ \end{pmatrix}$ + $k_3\begin{pmatrix} c\\ e\\ f\\ \end{pmatrix} = 0; dim(S) = 3$ Please let me know how to go about this. Thank you.
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Find a basis for the vector space of symmetric matrices with an order of $n \times n$ This is my thought: by definition of symmetry, $a_{i,j}=a_{j,i}$. Therefore, the basis should consist ${n^2-n} \over 2$ matrices to determine each symmetric pair. In addition, it should also consist $n$ matrices to determine each term in the diagonal. Therefore, the dimension of the vector space is ${n^2+n} \over 2$. It's not hard to write down the above mathematically (in case it's true). Two questions: Am I right? Is that the desired basis? Is there a more efficent alternative to reprsent the basis? Thanks!
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I don't remember the author or title, but the story is set down south. One day there was a flood and a new woman showed up. She got involved with the matriarch's son. Turns out she is a creature that came with the flood and her enemies start to disappear. I hope this may sound familiar to someone. I read it in the late 80's, the cover had an eye on it with the town flooded in the background. There were at least 6 books in the series. Thanks
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I have been searching for so long for a certain series of novels. The only things I remember about the series is that the covers had an eye and a house partly submerged under water. It was a series of 6 books, each with a different colour. The plot concerns a woman who mysteriously appears after a flood in a southern town ruled by the matriarch of a family. The mysterious woman ends up marrying this matriarch's son and then the fun begins: disappearances and good fortune to those who deserve it. If this sounds at all familiar, please help.
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I am using a string which contains a regex expression to validate an email, the email is validating properly,unless a "+" symbol is included in the email. if someone has a email id suppose like this "[email protected]", so at this point my regex is not working itz giving me a invalid username message,for else email id itz working fine here is my regex string strPattern = "^([0-9a-zA-Z]([-.\\w]*[0-9a-zA-Z])*@([0-9a-zA-Z][-\\w]*[0-9a-zA-Z]\\.)+[a-zA-Z]{2,9})$"; I tried using other regex which validates for special symbols but still i have the same error. string strPattern = "^[a-zA-Z0-9]+([a-zA-Z0-9_.\\$&-]+)*@[a-zA-Z0-9]+([a-zA-Z0-9_.\\$&-]+)*\\.([a-zA-Z0-9]{2,4})$"; if anyone can help out,it will be usefull,thanx
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Over the years I have slowly developed a that validates MOST email addresses correctly, assuming they don't use an IP address as the server part. I use it in several PHP programs, and it works most of the time. However, from time to time I get contacted by someone that is having trouble with a site that uses it, and I end up having to make some adjustment (most recently I realized that I wasn't allowing 4-character TLDs). What is the best regular expression you have or have seen for validating emails? I've seen several solutions that use functions that use several shorter expressions, but I'd rather have one long complex expression in a simple function instead of several short expression in a more complex function.
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In of phone cameras I came across one data point that intrigued me: They appear to write the sensor size as a fraction, in this example 1/5.8". What exactly does that mean? My hypothesis was that it was (1/5.8)" = 0.1724" = 0.4379cm, is this correct? And if so, why would you write it as a fraction?
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I'm wondering how sensor sizes are calculated. The Sony RX100 reportedly has a sensor size of 1" which is 13.2 x 8.8 mm according to the press release and various sites. How does that work? That's a pretty small inch. The Wikipedia page on has this chart: which doesn't really help. (The 1" format is labelled Nikon CX. Chart by Moxfyre under the CC-BY-SA license.) If full frame/35 mm refers to the horizontal size, what does 1" refer to?
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My cousin UK visit visa was refused with her one year old son and husband. The reason for her refusal is that she said they are traveling to visit her uncle and they will be spending 21 days. The Eco said she mentioned that she said she will spend 21 days and that spends 50,000 naira monthly on living expenses that they noticed that she spent more than 50000 in some month her bank statement. That her statement is inconsistent. Eco also said she said she will spend 1300 pound for her visit and her husband will support her with 200 pounds. Since her husband has been refused they are not convinced if she will get the 200 pounds. Her son was refused due to his parents refusal. She wants to reapply, but how soon can she do that. And how can she change her personal circumstances
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The UK Visas and Immigration Directorate publishes that provides helpful tips that can result in successful visa applications. Section 2 of this guidance opens is entitled "other documents you may want to provide" (emphasis mine). Section 2: other documents you may want to provide – all visitors This section provides guidance on the types of documents that you may want to provide to help us consider your application against the Immigration Rules. Previous travel documents/passports, which show previous travel. Financial documents showing that you have sufficient funds available. These must clearly show that you have access to the funds, such as: bank statements building society book proof of earnings such as a letter from employer confirming employment details (start date of employment, salary, role, company contact details) where a third party (who is either in the UK or will be legally in the UK at the time of your visit) is providing financial support to you e.g. a business, a friend or a relative, documents to show that they have sufficient resources to support you in addition to themselves and any dependant family should be provided The first item is "bank statements" and this ties in with the , which says... evidence that you can support yourself during your trip, eg bank statements or payslips from the last 6 months (Note 'eg' is a Latin abbreviation meaning "for example"; this appears to be optional rather than a fixed requirement.) Question: How should someone interpret this such that the chances of success are maximized? How many statements should I submit? What are they looking for and what do my bank statements tell about me?
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I have inatalled ubuntu 14.04LTS dual boot with windows 10. Problem is that ubuntu and windows 10 is in the same drive. Please help me to uninstall ubuntu without loosing my windows.
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Possible Duplicate: I have dual boot laptop having two os windows 7 and Ubuntu. I want to remove ubuntu and merge space with windows.
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If the Tesseract was in Asgard after the Avengers (Thor took it along with Loki) how come Von Strucker had it at the end of Captain America: The Winter Soldier? Even more at the end of Thor: The Dark World they said that they took the Aether to the Collector since they already had the Tesseract in Asgard. And didn’t want to Infinity Stones be together.
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The last time saw Loki's scepter (before it was shown in the post-credits scene of Winter Soldier), all the Avengers were standing around a defeated Loki and Black Widow was holding it. Is it implied that because HYDRA infiltrated S.H.I.E.L.D., they got hold of Loki's scepter?
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I have the Looting 3 enchantment on my iron sword and hit a few fireballs back at a ghast. Eventually, a fireball collided with the ghast, killing it, and I picked up the three ghast tears it dropped. Three seemed like an awful lot, as I'm used to one, or occasionally two, but three is new for me. Seeing as I had Looting 3 on my sword, did that effect how many ghast tears I got from killing the ghast, even though the ghasts' own fireball killed it?
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I got 2 ghast tears after I thought I deflected a fireball back at the ghast (with my looting 3 sword). But I was pretty close, so I might have just hit it. I'm not sure. If I deflect a fireball with a looting sword and it kills the ghast, do I still get the looting bonus?
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I have two sets which returns a specific value. I would like to carry out an operation on set apple. if length of this this set is greater than 0, i woulf like to calculate the elapsed time. If the time passed more than 10 sec, i would like to reset time to zero. Any suggestion to deal this? apple = set([1,5,9,13]) orange = set([2,4,6,8,10]) def fruit(apple,orange): if len(apple)>0: time_now = time.time() if time_now >10: apple.clear() time_now == 0 return apple, orange
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I would like to know how to put a time delay in a Python script.
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I know questions similar to these have been asked before. However, I could not deduce the answer to this question, because they only did tell me what I should do, but not why I should do that. I have a laptop which needs 19V DC power, but I do not know whether I have the original adapter. I have some old adapters which seem to fit, but, you could've already guessed it, they give different output voltages. Now I have multiple options: I plug an adapter with 17 V / 1200 mA into the device. I plug an adapter with 18 V / 1250 mA into the device. I buy a new adapter which outputs 19 V, and plug that into the device. Now I have the following questions: What will (most likely) happen with the laptop if I plug in abovementioned adapters? Is it okay, is it bad, does it harm the device? Does Amp. matter? This might be basic physics; can anyone post a link where this is perfectly explained?
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I have a laptop that says it needs a 19V 3.42A power supply. I have a Dell 20V 4.51A power supply. Can I use this power supply with my laptop, or will it destroy the machine?
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After running the following code in a directory (actually a sub-directory of my pictures folder, if that helps) consisting of nothing other than about 60 png images: for i in *; do mv "${i}" Surv${53+count}.`echo "${i}" | awk -F. '{print $2}'`; ((++count)); done I found that all but the last of these pngs images had vanished. Is there any way to restore them? At the time I thought that I had them backed up, but I am sad to discover that I have in fact not.
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Are there any tools, methods, incantations to recover recently deleted files on Ubuntu? If it makes any difference, I want to recover a 2.x database file. But would be better to have a method/tool that works on any kind of file.
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We are staying at a resort in Basye this summer and want to know the easiest way to take a couple of day trips into DC. I'm thinking that we would drive most of the way in, then use a park and ride and take the metro to the National Mall. I'm assuming that traffic and parking in DC would be difficult.
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I plan to drive to Washington, DC, but my understanding is that the Metro is far better than driving for actually getting around downtown DC. First of all, is that assumption correct? Assuming the Metro is indeed the way I should ultimately get to my downtown destination, how close should I drive before finding a Metro station? Should I stop at the first one on the outskirts in Maryland, or should I keep going into the city a bit? I'm primarily concerned with avoiding traffic if possible as well as generally shortening my travel time. The travel will be occurring during a weekend (4th of July weekend) in case that is relevant. My destination in DC is off the Navy Yard station of the Metro Green Line. Follow-up: I might have found a last-minute hotel deal downtown. Can I park overnight at the Metro stations that are being suggested?
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This question isn't answered here: That question asks about what happens when the following word begins with a consonant in general. This one is asking about the various possibilities for an intervocalic tap if a following word is an unstressed function word beginning with /t/. It's also asking whether there's any possibility for regressive assimilation here. I read this in American accent book. I quote the text exactly how it is written in the book: The suffix -ed is not pronounced precisely when it is linked to another consonant. For example, mailed the sounds very much like mail the in the following sentences: I already mailed the letter. I will mail the letter. The suffix -ed is not heard at all when it is linked to /t/ or /d/. For example talked to sounds identical to talk to in the following sentences: I talked to her yesterday. I talk to her every day. Okay but then my question is, how do Americans distinguish between these two sentences: I try to call you. I tried to call you. In the first sentence the /t/ will be realised by a voiced tap because it occurs between two vowels. In the second will we get a regular [t] and then a voiced tap? Will we get a double tap or a double length tap? Or will we just get a single tap? Or maybe here we will just get two regular /t/s? Do native speakers differentiate between "I tried to call you" and "I try to call you" from the context?
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How can we distinguish, for example, these two sentences just by listening to the pronunciation? They first kill the trees. They first killed the trees. When pronouncing kill the trees, we have one [d] that is for the. When pronouncing killed the trees, we have two [d] that is for killed and the. Native speakers pronounce both sentences so that we just hear one [d], so we don't know the tense by pronunciation in these cases. Am I right? Is there any special stress or extension of a sound that signals the difference between them?
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Is there any way to find the java version from a compiled java .class file ?
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Do any of you know of a tool that will search for .class files and then display their compiled versions? I know you can look at them individually in a hex editor but I have a lot of class files to look over (something in my giant application is compiling to Java6 for some reason).
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I understand that the basic premise of bootstrapping a dataset with N data points is: Sample with replacement from N a number of draws, D, equal to N; Repeat step 1 K times - that is, as much as you can stand computationally (slash when the estimated parameters/distribution is relatively normal and stable with minimal gain from increasing k, etc.) Why does the number of draws D equal N? I can understand intuitively that it wouldn't be great to select fewer draws than N, since fewer draws will limit your ability to correctly estimate the mean. I also saw suggesting that there are cases when it might be permissible to draw a D smaller than N. But since you're sampling with replacement, what is stopping you from drawing a D twice as large as N? Or three times? Is it because it would "over-weight" more data points with more frequent representation in the dataset relative to rarer datapoints? Thank you for your help!
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I want to predict future returns over a 20 days horizon using an ARMA-GARCH model fitted to my data. The goal is to estimate different risk measures like VaR or CVar. In particular say I use AR(1) GARCH(1,1). The smaple I use for estimation has 500 observation of daily logreturns. That's what I usually do: Estimate AR, ARCH and GARCH coefficients Calculate standardized residual by dividing residuals by estimated conditional variances The standardized residuals constitute my INVARIANTS that is the i.i.d. series from which I extract bootstrap samples to generate scenarios. The bootstrap samples are extracted by simulating a uniform between 1 and the sample size (500 in this case) and then taking the value corresponding to that position in the vector of the standardized residuals. The problem is that I have only 500 standardized residuals and I think 500 is the maximum size of bootstrap samples I can extract. My colleague instead extracts 100000 observations out of the original sample of $N=500$ observations. I feel that this is somehow incorrect conceptually. Simulating only one step forward would produce exactly the same scenario as the initial one, but with repeted values that add no information. My colleague claims that if he wants to project over a longer period, e.g. 20 days horizon, the 100000 extractions from the original sample of N=500 obs. would produce many different scenarios at the final horizon, providing a CDF that is smooth. Actually thit is true because, although the values are simply repeated in the first step, after that they can sum up in many different ways. That being said I don't feel this is right. I proposed an alternative that is: From the standardized residuals create a smoothed empirical CDF, say kernel Exctract uniforms between 0 and 1 and feed it to the empirical smoothed CDF, i.e. inverse transform. This way I feel more confortable to say that I can generate a bootstrab sample of size greater than the original one, but still I am not sure. I am studying bootstrap theory on a book from Efron Efron, Tibshirani - An Introduction to the Bootstrap - Springer US (1993) but there are many concepts that I don't understand yet. My question are: Would you give your opinion on the problem I just showed below? Would you suggest any valid matherial for studying bootstrap other than the book I mentioned? I think that this application of bootstrap is somehow different to the one explained in Efron's bookm, that is evaluating confidence intervals for estimated paramenters. What do you think about it? Any comment would be much appreciated I apologize for the length of the post but I tried to be as much concise as I could. Thank you
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Is there any hope to bring back Unity on Ubuntu 17.10? Personally, I (still) don't like Gnome. The main reason I like Unity is for the top bar integration (and the Alt suggestions). I just couldn't find any good extensions for Gnome to do that. I upgraded from 16.10 to 17.04 and then 17.10 (which came with Gnome). Everything went fine, but I just want Unity back... How to do that? I already tried: ionicabizau@notebook:~$ sudo apt install unity [sudo] password for ionicabizau: Reading package lists... Done Building dependency tree Reading state information... Done unity is already the newest version (7.5.0+17.10.20171010-0ubuntu1). 0 upgraded, 0 newly installed, 0 to remove and 15 not upgraded.
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Now, that Ubuntu 17.10 is out, and Unity 7 is replaced with Gnome 3, is there a way to install and use Unity7? I know Unity is still in the repositories, so it should be possible, right?
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These were stored in their canisters for over 60 years. I have copied all of them. What is the best way to store them? Should I straighten them out and put them in protective sleeves? Or should I leave them as-is, since they are getting brittle to straighten?
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I bought 35mm dedicated film scanner (Nikon CoolScan III) and I'm planning to digitize old negatives and slides I found at home. How should I store and preserve these slides and films after I cut them and scan? How to choose best negative pages/sleeves, binders etc. and what to avoid?
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I am a student currently using java and I am having a hard time programming a high and low guessing game. I cannot use looping or "while" code. Any thoughts? This is what I have as of now: public class FinalProject1 { public static void main(String [] args) { System.out.println("Number Guessing Game 1-1000\nGuess a number"); guess(); } public static int random() { int x = (int)(1000*Math.random() + 1); return x; } public static void guess() { int num = random(); int tries = 0; Scanner keyboard = new Scanner(System.in); String inputString = keyboard.nextLine(); int input = Integer.parseInt(inputString); if (input > num) { System.out.println("Guess a higher number"); inputString = keyboard.nextLine(); } else if (input < num) { System.out.println("Guess a lower number"); inputString = keyboard.nextLine(); } else if (num == input) { System.out.println("You Win"); } } }
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Can anybody suggest programming examples that illustrate recursive functions? There are the usual old horses such as Fibonacci series and Towers of Hanoi, but anything besides them would be fun.
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Given a sequence $(s_n)$ in $\mathbb R$ such that $$\lim \limits_{n \to \infty}( s_{n+1}-s_n)=0,$$ I am asked to prove $(s_n)$ converges. I know all Cauchy sequences converge in $\mathbb R^k$. So I want to prove that $(s_n)$ is Cauchy. I am stuck as to how to show the given sequence is a Cauchy. Thank you.
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Let $a_n$ be an infinite sequence. The limit of the difference of two consecutive members is equal to $0$. Can we conclude that the sequence itself has a limit? My attempt: We have $$ \lim_{n\rightarrow\infty}{a_n} - \lim_{n\rightarrow\infty}{a_{n-1}} = 0 $$ since as $n$ approaches infinity $a_{n-1}$ gets arbitrarily close to $a_n$ the sequence cannot diverge or be bounded but have no limit. Is my proof correct and how would I be able to formalize the last sentence? Thanks
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I am stuck finding a way to prove/disprove this limit of a sequence. Assuming that $\lim\limits_{n\to\infty}(a_{n} - a_{n-2})=0$ for the sequence $a_n$, prove or disprove that $$\lim\limits_{n\to\infty}\frac{a_{n} - a_{n-1}}{n}=0.$$ An explanation on how to work this through would be very appreciated.
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If the sequence satisfies the property lim$_{n\to \infty}(a_n-a_{n-2})=0$, prove that lim$_{n\to \infty}\frac{a_n-a_{n-1}}{n}=0$. I am experiencing difficulty showing this rather obvious result. By definition, we know that for any $\epsilon \gt 0$, there is some $N$ such that if $n \gt N$ then $|a_n-a_{n-2}|\lt \epsilon$ My guess is that I need to write $|a_n-a_{n-1}|$ as sums of $|a_n-a_{n-2}|$ from $n$ to $N$. However, I am stuck with forming an inequality here. I would appreciate any solutions or suggestions.
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First of all, I have gone through . But I am not satisfied, and I do agree with "Reviewing is important to keep the quality of questions and answers high". My question is, why that notification is there even after I ran out of the daily limit. I mean can't they disable that if user has reached the limit? What is the point of having such a notification on the top-bar if we have nothing to do? Is there any option to disable that?
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Now that I've reached 2k on Stack Overflow, I get access to the "Suggested Edits" review queue. Although I only have 20 edits per day, the "suggested edit awaiting" icon in the top bar is always there and it bothers me a lot! My suggestion is to apply one of three solutions: Remove the suggested edits icon when we reach the maximum (50) edits Remove the Highlight (orange) on the suggested edits Remove the suggested edits part when we click on it What do you think?
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Is it possible to find the implicit parallel curve of $f(x) = x^2$? If so what would it be and how does one find it?
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I have a simple parabola in the form $y = a + bx^2$. I would like to find the formula for a curve which is parallel to this curve by distance $c$. By parallel I mean that there is an equal distance along a line perpendicular to the tangent to my curve at all points. I've established that the curve isn't in the form $y = a + c + dx^2$, whilst I can make this satisfy for $x=0$ and $x$ equal to one other number is isn't valid across the range. Any help much appreciated. Rob
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Following is my function to send mail using codeigniter. There is issue related to using link only, I have tested all other things. If I remove link or use of domain name mail goes to inbox. public function send_notification() { $body = "<div style='width:100%; margin:0 auto;'> <table style='background-color:#ffffff;padding:0 10px; width:100%;box-shadow: 0px 0px 4px #263b91;'> <tr> <td style='text-align:center;'> <a href='https://example.com'><b>Click Here</b></a> </td> </tr> <!-- mail body --> <tr> <td> <p style='width:100%;'> <h4>Message</h4> </p> </td> </tr> </table> <!-- footer --> <table style='width:100%;background-color:#8dc440;box-shadow: 0px 2px 3px 0px #000;'> <tr> <td> <p style='font-size:14px; text-align:center;'> <small>&copy; 2017 All Rights Reserved</small> </p> </td> </tr> </table> </div>"; $subject = "Notification from Example"; $config['protocol'] = $this->config->item('protocol'); // 'smtp' $config['smtp_host'] = $this->config->item('smtp_host'); //mail.example.com $config['smtp_port'] = $this->config->item('smtp_port'); //25 $config['smtp_timeout'] = $this->config->item('smtp_timeout'); //7 $config['smtp_user'] = $this->config->item('smtp_user'); [email protected] $config['smtp_pass'] = $this->config->item('smtp_pass'); $config['charset'] = $this->config->item('charset'); utf-8 $config['newline'] = $this->config->item('newline'); \n\r $config['mailtype'] = 'html'; // or text $config['validation'] = TRUE; // bool whether to validate email or not $this->email->initialize($config); $this->email->from('[email protected]','Exaple'); $this->email->to('[email protected]'); $this->email->subject($subject); $this->email->message($body); $this->email->send(); }
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This is a tricky one and I've always relied on techniques, such as permission-based emails (i.e. only sending to people you have permission to send to) and not using blatantly spamish terminology. Of late, some of the emails I send out programmatically have started being shuffled into people's spam folder automatically and I'm wondering what I can do about it. This is despite the fact that these particular emails are not ones that humans would mark as spam, specifically, they are emails that contain license keys that people have paid good money for, so I don't think they're going to consider them spam I figure this is a big topic in which I am essentially an ignorant simpleton.
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I have some problem now with converting the c++ class into python code using swig. This is my header file: template<typename T> class Dictionary { private: int size; T *array; public: Dictionary(int s); void set(int elem, T val); void get(); ~Dictionary(); }; This is my cpp file: template<typename T> Dictionary<T>::Dictionary(int s) { this->size = s; this->array = new T[s]; } template<typename T> void Dictionary<T>::set(int elem, T val) { array[elem] = val; } template<typename T> void Dictionary<T>::get() { for(int i=0; i<this->size; i++) { cout << i << array[i] << typeid(array[i]).name() << endl; } } template<typename T> Dictionary<T>::~Dictionary() { } And my interface file: %module Dictionary %{ #include "Dictionary.h" %} %include <std_string.i> %include <std_vector.i> %include "stl.i" %template(_string_list) std::vector< std::string >; %include "Dictionary.h" %template(dictint) Dictionary<int>; The problem is that I always get an error like undefined symbols for architecture Undefined symbols for architecture x86_64: "Dictionary<int>::get()", referenced from: _wrap_dictint_get(_object*, _object*) in Dictionary_wrap.o "Dictionary<int>::set(int, int)", referenced from: _wrap_dictint_set(_object*, _object*) in Dictionary_wrap.o "Dictionary<int>::Dictionary(int)", referenced from: _wrap_new_DictionaryD(_object*, _object*) in Dictionary_wrap.o "Dictionary<int>::~Dictionary()", referenced from: _wrap_delete_dictint(_object*, _object*) in Dictionary_wrap.o ld: symbol(s) not found for architecture x86_64 clang: error: linker command failed with exit code 1 (use -v to see invocation) I wrote this command: At first swig -c++ -python -py3 Dictionary.i The second one is: g++ -g -ggdb -c -std=c++0x -I/usr/local/Cellar/python/3.7.0/Frameworks/Python.framework/Versions/3.7/include/python3.7m Dictionary.cpp Dictionary_wrap.cxx And the third: gcc -dynamiclib -o _Dictionary.so *.o -L/usr/local/Cellar/python/3.7.0/Frameworks/Python.framework/Versions/3.7/lib/ -lpython3.7 -flat_namespace And on the third line, it crashed. Please help me
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Quote from : The only portable way of using templates at the moment is to implement them in header files by using inline functions. Why is this? (Clarification: header files are not the only portable solution. But they are the most convenient portable solution.)
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I recently ran two tests in R - one using glm() and one using lm() with the goal being to test the relationship between a binary response and binary predictor. I ran glm() first and got an estimate of -0.68 for the predictor coefficient which I thought was pretty good. P<.05 and AIC of 653. When I ran lm() however I got an estimate of -.14, a multiple r-squared of .008, P<.05. My understanding is that linear regression is usually a poor choice for a categorical response compared with logistic regression, but when is this not the case? I noticed in this post that the author states there's middle ground where it does make sense to use linear regression. Are there any common rules (or rules of thumb you personally use) that determine when to try out linear regression on a categorical response? Do any of these differ from the author's cases?
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What is the difference between linear regression and logistic regression? When would you use each?
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Assuming you're parents that see your young son doing something you don't like, and you want to avoid him to do it. What's of these following ways more natural? Don't do it! or Don't do that!
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Is this sentence correct? I did it yesterday, but I’m not going to do it again. I’m not sure about it. Should I replace “it” with “that”? I did it yesterday, but I’m not going to do it again. I did it yesterday, but I’m not going to do that again. I did that yesterday, but I’m not going to do it again. I did that yesterday, but I’m not going to do that again. Are all versions correct?
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How to reinstall windows 7 if I have win7 x32 installed and I want to replace it with win7 x64?(I don't want to format my hard drive)
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My friend installed Windows 7 on his computer (upgrading from XP). He wasn't sure if his processor supported x64 or not, so he installed the x86 version, just to be on the safe side. After I looked it up, it turns out his processor does support x64, and now we want to upgrade. The question is: is it possible to upgrade without completely re-installing the OS? Can I? Or do I have to format the C: partition again?
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Find a point on the plane of a triangle such that the sum of its distances from three vertices is minimum. I am guessing that it is the centroid but I can't prove that.
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Given a triangle in a plane with vertices A, B, C, find the point T that minimizes the sum of distances between A-T, B-T, and C-T. I can experimentally determine this point by sampling the space and finding the minimum via an attractive, interactive web page: Drag any vertex to see the gradient of value sums change and the point T be updated. I find it interesting to note that moving any vertex towards or away from T does not affect T, until the point where the vertex touches T and causes it to move along with it. However, an experimental determination is neither efficient nor accurate, and prevents me from graphing other interesting properties such as the arcs of the vertices when a fixed sum is required. Please help me find the equation for T (preferably in terms of vectors, as the answer should be the same in 2D or 3D). Edit: Based on the answer, I've created an updated interactive using the calculated point and showing the construction:
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Recently, I’ve received a couple of spam event invitations in Calendar on my Mac. The most recent had only Chinese text, and recurred at 5:46am every day. I am able to decline these by clicking on the invitations button in the toolbar (that only appears when an invitation comes in). However, ideally I’d like to not receive these spam invitations at all. As I’ve never received a genuine invitation through Calendar, I thought I might be able to turn off the invitation feature. However, I can’t see any controls for this in Calendar preferences or the Internet Account system preferences. Through what mechanism do these invitation arrive? If I understood what mechanism it was, I might be able to turn it off. I have two Calendar accounts enabled: iCloud, and Facebook. I can’t see anything in my e-mail, so I presume they’re not regular e-mail spam. Since first writing this question, I’ve had a similar invitation come through in Reminders:
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Today I've suddenly received spam calendar invitation for $19.99 Ray Ban sunglasses (never subscribed, checked, searched or visited any related site, so clearly spam) and it has other visible email accounts within the invitation. I'm wondering if I should be worried whether my accounts been compromised or a simple email from anywhere just plops this in my calendar without review. Questions to be answered: What should I check/setup in order to make sure my iCloud account is safe? How can I delete this invitation without sending a notification to the sender, so as to prevent them from knowing my email address is live? How can I prevent these notifications in the future? Here's an image:
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In a football game, the sides in the soccer field are determined on the basis of a single coin flip by the referee and the team which correctly guesses the flip result gets its desired side. What is the probability that a team will have to wait until its 8th game to get its desired side? I am stuck with this question, any help would be much appreciated! I thought, $\frac{1}{2}^8$ but it is wrong.
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I am stuck with this question, I thought $(\frac{1}{2})^7$ but it is wrong. Any help would be much appreciated. In a football game, the sides in the soccer field are determined on the basis of a single coin flip by the referee and the team which correctly guesses the flip result gets its desired side. a) What is the probability that a team will have to wait until its 7th game to get its desired side?
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How do I forward X when switching users? I can ssh -X [email protected] and open GUIs just fine. However, then when I sudo su to root, the X11 forwarding seems to stop because the windows never seem to launch. ssh access is disabled for root, otherwise I would just connect directly.
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Following are other questions which I think I need to know: From a non X Session? (meaning root isn't logged into X) If multiple people were logged in on X, could I auto-detect who was on which screen, and thus programmatically detect which screen I need to launch the app on? Can I launch the app as the user? ( ok I'm 99.999% sure this is a yes ) Can I detect if users of group X are logged in to X?
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Hey guys but I'm not sure if it's for my micro 4/3 camera:
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When looking at a lens name, there are a lot acronyms describing its features (often specific to the manufacturer). Examples, Nikon: Nikon AF-S DX 16-85mm VR f/3.5-5.6G IF-ED Nikon AF-I 600mm f/4D IF-ED Nikon AF-S VR Micro-NIKKOR 105mm f/2.8G IF-ED Examples, Canon: Canon EF 85mm f1.2L USM Mark II Canon 70-300mm f/4.5-f/5.6 DO IS Examples, Sigma: Sigma 150mm F2.8 EX APO DG HSM Macro Sigma 70-200mm F2.8 EX DG OS HSM Sigma 50-150mm F2.8 EX DC APO HSM II How do I decipher these lens codes from different manufacturers?
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I'm quite new to game development, so would like to get a consensus on methods of doing this. My game features a 2D character that is able to pick up and drop objects, for example, a stick. My question is: is it advisable / possible to manipulate the image of the character and image of the stick to make it look like the character is now carrying a stick; or is it best to have a separate sprite sheet for the character with the stick and the character without? EDIT: To be clear - I have a lot of characters, with a few items (4 separate items and over 20 characters)
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I want to create a 2D game but I'd like to have the character to wear tons of different equipments on different combinations, like a RPG or something. So let's say the user changes his/her shoulders and pants, this must be shown to the player and all these different equipments must follow the different characters action (hitting, being hit, spelling magic, etc.). I see a few problems that I'd like to know the best approach/algorithm/architecture to solve. 1 - Sprites or Animations Should I create different sprites for each equipment in each action animation? Is it better to just have the equipment sprite and animate it directly on code like rotating and translating (using something like tween on Flash)? Is there any other better option? (I really don't like the ideas above) 2 - Positions Let's say during one of the character's move he starts looking directly in front to the player's view but ends his movement showing his right side to the player (like if he swings his sword from one side to the other). If we consider one part of the user, like his head for example, it starts in front and then turns left. It means at least 3 different positions for each head equipment (helmet, cap, whatever). This surely influence the answer of #1 question. How is the best way to achieve that? 3 - Layers Let's consider a character move where he spins 360 degrees with his arms open. At the beginning of the animation, his right hand is close to the user's view and then, at the middle of the movement, this is probably behind the character's body on the animation. Whatever is the option on #1 question, you surely needs to use some kind of layer model to make this sprite or animation to starts closer to the player's view and later change to far away from player's view. Is there any good way to do that? I know the question is quite long and difficult to understand. Let me know if you think it's better to have some drawings to try to explain which one and I'll try to do that.
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What I am trying to do is add an array to an arraylist. I've looked at other examples that tell me to do what I am doing, but I get nonsense output when I run the program. I would also like to access certain elements of an array within the arraylist, and I have no idea how to do that. static int elements = 10; //Or whatever number you'd like public static void main(String[] args) { int[] person = new int[4]; ArrayList personID = new ArrayList(); experiment(personID, person); } private static void experiment(ArrayList personID, int[] person) { for(int i = 0; i < elements; i++) { person[0] = i; person[1] = i; person[2] = i; person[3] = i; personID.add(person); } System.out.print(personID); } Output: [[I@e1cba87, [I@e1cba87, [I@e1cba87, [I@e1cba87, [I@e1cba87, [I@e1cba87, [I@e1cba87, [I@e1cba87, [I@e1cba87, [I@e1cba87] Not that much of an explanation is needed, but I declare the array and arraylist, pass them to a function which keeps giving the array's elements different values and then, supposedly, adding the array itself to the arraylist for each iteration. The output, though, it nothing like what I am looking for. I could do another loop to print each array element for each spot along the array list, but I don't know how to do that. I figured System.out.print(personID.get(i[0]); Or System.out.print(personID.get(i)[0]; But it doesn't work and I'm lost... Thank you for dealing with me!
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In Java, arrays don't override toString(), so if you try to print one directly, you get the className + '@' + the hex of the of the array, as defined by Object.toString(): int[] intArray = new int[] {1, 2, 3, 4, 5}; System.out.println(intArray); // prints something like '[I@3343c8b3' But usually, we'd actually want something more like [1, 2, 3, 4, 5]. What's the simplest way of doing that? Here are some example inputs and outputs: // Array of primitives: int[] intArray = new int[] {1, 2, 3, 4, 5}; //output: [1, 2, 3, 4, 5] // Array of object references: String[] strArray = new String[] {"John", "Mary", "Bob"}; //output: [John, Mary, Bob]
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print(*cmath.polar(cnum), sep ='\n') I just came across this line while solving a complex number problem. What is the use of * before cmath?
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In the following method definitions, what does the * and ** do for param2? def foo(param1, *param2): def bar(param1, **param2):
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Let $\phi(x)=m$, where $\phi(x)$ is Euler’s phi function, And $x=\prod_{i=1}^{n}p_i^{a_i}$ Thus: $$\phi(x)=\phi\left(\prod_{i=1}^{n}p_i^{a_i}\right)= \prod_{i=1}^{n}p_i^{a_i}-p_i^{a_i-1} =m$$ $$\iff m= \prod_{i=1}^{n}p_i^{a_i-1}\left(p_i-1\right) $$ Now let $d_i=p_i-1$: $$m =\prod_{i=1}^{n}p_i^{a_i-1}d_i= \prod_{i=1}^{n}\frac{p_i^{a_i}}{p_i}d_i= \prod_{i=1}^{n}p_i^{a_i}\frac{d_i}{p_i} $$ $$\iff m=x \prod_{i=1}^{n} \frac{d_i}{p_i} \iff x= \frac{m}{\prod_{i=1}^{n}d_i}\prod_{i=1}^{n}p_i$$ I think that this is the solution to the equation $\phi(x)=m$, but how can i use this result to solve it?
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I am having trouble with understading how inverse totient function works. I know it can have multiple solutions but I don't understand how to find all of them for bigger numbers. For example how would one approach to problem of solving this equation: ϕ(n) = 180 I do understand that one should represent ϕ(n) by product rule and somehow conclude numbers by combining product rule expression for ϕ(n) to get all numbers n. But it seems as very long process that I don't understand. My question is how I should think when looking at prime numbers expression for ϕ(n) and how should I eliminate some results? I was trying searching other similiar question and I still can't find some general algorithm for solving this problem. Thanks! EDIT: I would like to know how to calculate this problem by hand
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I have looked at and while it is very similar to the question I'm asking I ran into the same issue after implementing its syntax. I feel like I'm still missing something related to how to implement the correct syntax for the below. where_query = '"field_name" <= ' "{0}.format(year_range)" I'm trying to make what into a geoprocessing tool that can be reused in ArcMap, but I'm receiving the following error. It looks like an issue with the way that I'm formatting the where_query variable, but I can't seem to get it right. Traceback (most recent call last): File "C:\ArcPy\mean_center_drift.py", line 19, in <module> arcpy.Select_analysis(in_feature, year_out_name, where_query) File "c:\program files (x86)\arcgis\desktop10.3\arcpy\arcpy\analysis.py", line 84, in Select raise e ExecuteError: ERROR 000358: Invalid expression 1 Failed to execute (Select). and here is the code in its current form. import os import arcpy in_feature = arcpy.GetParameterAsText(0) out_features = arcpy.GetParameterAsText(1) origin_year = arcpy.GetParameterAsText(2) field_name = arcpy.GetParameterAsText(3) for x in range(10, 140, 10): year_range = int(origin_year) + x where_query = '"field_name" <= ' "{0}.format(year_range)" year_out_name = os.path.join(out_features, "Years_{0}".format(x)) mean_out_name = os.path.join(out_features, "Mean_{0}".format(x)) arcpy.Select_analysis(in_feature, year_out_name, where_query) arcpy.MeanCenter_stats(year_out_name, mean_out_name, "#", "#", "#")
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I am trying to loop through a shapefile, selecting each feature in turn and copying it to a temporary shapefile to by included in a union analysis. I'm using a cursor to find the ID name for each feature which I'm setting to a varible 'Name'. Whenever I try to use this variable as part of the where clause in arcpy.Select_analysis I get an error: ExecuteError: ERROR 999999: Error executing function. An invalid SQL statement was used. An invalid SQL statement was used. Failed to execute (Select). The code I'm using is: Name = 101 where = "\'\"StudyID\" = \\'"+str(Name)+"\\'\'" arcpy.Select_analysis("C:\\input.shp", "C:\\output.shp", where) If I type it out without using the variables: arcpy.Select_analysis("C:\\input.shp", "C:\\output.shp", '"StudyID" = \'101\'') it works fine What to I need to do to fit the variable into the sql statement?
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I am trying to show that $|a+b|\geq||a|-|b||$. I considered doing an exhaustive process, that is, $a+b \geq 0$, $a+b \leq 0$, and $a+b=0$, and then for each of those considering $|a|-|b| \geq 0$, $|a|-|b| \leq 0$, and $|a|-|b|=0$ (9 combinations) After doing the first of these ($a+b \geq 0$, $|a|-|b| \geq 0$), I came to the following: $$a+b \geq |a|-|b|$$ and attempting to show this was true. However, I am unable to show that this is the case. Additionally, going through such an exhaustive process simply strikes me as wrong or unnecessarily cumbersome. Any suggestions are appreciated.
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I've seen the full proof of the Triangle Inequality \begin{equation*} |x+y|\le|x|+|y|. \end{equation*} However, I haven't seen the proof of the reverse triangle inequality: \begin{equation*} ||x|-|y||\le|x-y|. \end{equation*} Would you please prove this using only the Triangle Inequality above? Thank you very much.
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Can I install Ubuntu 16.04.1 desktop amd64 on a laptop with Intel(R) Core(TM)2 Duo CPU T7100 @ 1.80 GHz and 2 Gb of RAM? I already have Windows 7 and it runs on 32 bit. I want to install Ubuntu along Windows 7 and using pictures, videos and books with both systems. Is it possible?
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I'm thinking about installing Ubuntu Desktop, but I don't know what flavor is the best for my system. What are the minimum and recommended hardware requirements? What kind of CPU? How much memory? Should I have Hardware Acceleration? What flavor should I use? This is an attempt of a canonical answer. My answers have the "official requirements", the recommended are a mix of official sources and opinion based (along with the answer it's told the source). You can comment or edit if you feel that the information is obsolete or incomplete. It is a good rule of thumb that any system capable of running Windows Vista, 7, 8, x86 (Intel) OS X will almost always be a lot faster with any Ubuntu flavor even if they are lower-spec than described below.
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I am trying to uninstall Ubuntu on a Windows 10 dual boot. I understand that I must delete the partitions holding Linux and the Linux swap, but do not know how to proceed to get rid of boot entry and GRUB. I have read that I can use efibootmgr on a live version of Ubuntu to delete the Ubuntu entry, but I have also read that I can delete the Ubuntu folder in the EFI directory through Windows. Are these two methods the same or do I have to use both of them to completely erase traces of Ubuntu? Thank you for your help.
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I have dual booted Ubuntu with Windows 7. I wanted to uninstall Ubuntu. So as per an answer for one of the related questions on this site I did the following: Deleted the Ubuntu Partition through Windows. As per the answer now I was supposed to boot Windows from USB & then do "repair startup". But Windows could not find any problem hence nothing was done. So when my laptop booted normally (i.e. from HDD) it was showing some error like GRUB:/ unknown file system. I dont remember the exact words but it was something like this. Thus I couldn't boot windows neither Ubuntu. So again I had to install Ubuntu. But now my question is how do I remove Ubuntu so that my laptop returns to the previous state of installing Ubuntu? UPDATE: Seems that it wasnt on this site. My mistake :P .Here is the link
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The tag doesn't hide: Spoiler Quote Look, not hidden!
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Tags in spoilers are always visible, even if you don't put your mouse on the spoiler (on for example). See the screenshot: Looks a bit strange on this site too: that needs !
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I have joined a few different Stack Exchange communities and I have noticed that when I join a new one, like this, my reputation points go to 1, even though I have more reputation on other Stack Exchange sub domains. I am joining or logging into Stack Exchange via my Google account, and thought because I used the same Google account when logging in, my reputation points would transfer over. I am not a reputation hog or overly concerned about fake internet points, but when browsing other Stack Exchanges and clicking other people's user names, I noticed (or thought I noticed) reputation from other sub domains seemed to transfer to the all sub domains. For instance, a guy in the DIY Stack Exchange has 2k reputation earned from the WordPress Stack Exchange (just an example). So I guess my question is two parts: Is reputation on Stack Exchange websites cross domain? If so, how does one link their Stack Exchange logins?
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On Stack Exchange, users may gain a certain level of reputation. What does reputation do? How can a user gain or lose reputation? See also in the Help Center - Maximum amount of votes a user can use in a day and reputation requirements to vote. - How to get an exact overview of the actions that got you your reputation. - A full list of all privileges granted at each reputation level on all sites.
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Downloaded different versions and from different places, still cannot get it work on 14.04. I could get it to run successfully on OS X and Ubuntu 12.04. drwxrwxrwx 5 root root 4096 Sep 5 17:14 ./ drwxr-xr-x 10 root root 4096 Aug 19 17:39 ../ drwxr-xr-x 3 root root 4096 Aug 26 20:51 opt/ drwxrwxr-x 4 achippa achippa 4096 Aug 26 20:50 sublime_text_3/ -rw-r--r-- 1 achippa achippa 7557246 Sep 5 17:14 sublime_text_3_build_3065_x64.tar.bz2 -rw-r--r-- 1 achippa achippa 6369566 Sep 5 16:53 sublime-text_build-3065_i386.deb drwxr-xr-x 4 root root 4096 Aug 26 20:51 usr/ achippa@ubuntu:/usr/local/src$ cd sublime_text_3/ achippa@ubuntu:/usr/local/src/sublime_text_3$ ./sublime_text -bash: ./sublime_text: cannot execute binary file: Exec format error achippa@ubuntu:/usr/local/src/sublime_text_3$ /usr/local/bin/subl Unable to load libgdk-x11-2.0.so Unable to load gdk_cairo_create from libgdk-x11-2.0.so Unable to load gdk_cursor_new_for_display from libgdk-x11-2.0.so Unable to load gdk_cursor_unref from libgdk-x11-2.0.so ... With i386.deb I see a bunch of unable to load... errors. With x64_tar.bz2, I see an Exec format error. Which is the right file to download for 64-bit Ubuntu 14.04.
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I installed Sublime Text 2 on 12.04 as per this . However I don't have adequate permissions when launching the program from the Unity launcher. For example I cannot install packages, or if I add a folder to the sidebar when I close Sublime and reopen, the folder is no longer listed. If I run sudo sublime in the terminal all changes remain after closing. I've tried chown-ing the Sublime Text 2 folder in usr/lib sudo chown -R mylogin:mylogin /usr/lib/"Sublime Text 2" but this seemed to have no effect.
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If $X$ has a binomial distribution with parameters $n$ and $p$, show that \begin{align*} \textbf{E}\left(\frac{1}{1+X}\right) = \frac{1-(1-p)^{n+1}}{(n+1)p} \end{align*} MY ATTEMPT Since $X\sim\text{Binomial}(n,p)$, we have \begin{align*} \textbf{E}\left(\frac{1}{1+X}\right) & = \sum_{x=0}^{n}{n\choose x}\frac{p^{x}(1-p)^{n-x}}{1+x} = (1-p)^{n}\sum_{x=0}^{n}{n\choose x}\frac{1}{1+x}\left(\frac{p}{1-p}\right)^{x}\\\\ & = \frac{(1-p)^{n+1}}{p}\sum_{x=0}^{n}{n\choose x}\frac{1}{1+x}\left(\frac{p}{1-p}\right)^{x+1} \end{align*} This is as far as I can get. Could someone help me out? Thanks in advance!
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The problem: X is a binomial random variable, find $E[\frac{1}{X+1}]$ n and p are not given PDF for a binomial distribution is $\binom{n}{k}p^k(1-p)^{n-k}$ Expected value is $\sum{x_ip(x_i)}$ But this is where I get stuck, I'm really rusty on my statistics and I'm not sure exactly how to structure it in the next step? I think I want to get the form of the following out of the summation $\sum _{k=0}^{n} \binom{n}{k}p^k(1-p)^{n-k} = (p + 1 - p)^n = 1$ But I'm not sure if it should look like $\sum \frac{1}{xp(x)+1} $ and if it should where to go from here?
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I have just upgraded my system but it boots to Low Graphics mode by default. I have seen questions on how to solve this problem and they all suggest to run a couple of commands from a command-line interface. But there isn't any command-line console by default in Low Graphics mode and hence, I cannot run those commands. And, the answers I saw to solve the problem doesn't explain this situation either. How to switch to a command-line console in order to run the commands in Low Graphics mode?
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Note: This is an attempt to create a canonical question that covers all instances of "low-graphics mode" error that occurs to a user, including but not limited to installation of wrong drivers, incorrect or invalid lightdm greeters, low disk space, incorrect installation of graphics card like ATI and Nvidia, incorrect configuration of xorg.conf file while setting up multiple monitors among others. If you are experiencing the "low-graphics mode" error when trying to login but none of the following answers work for you, please do ask a new question and then update the answers of this canonical question as and when your new question gets answered. When I try to boot into my computer, I am getting this error: The system is running in low-graphics mode Your screen, graphics cards, and input device settings could not be detected correctly. You will need to configure these yourself. How do I fix the failsafe X mode and login into my computer? Answer index:
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