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$$S = 1 - \frac12 + \frac13 - \frac14 + \frac15 - \frac16 + \frac17 - \frac18 + \frac19 - \frac1{10} + \frac1{11} - \frac1{12}\ldots\text{(to infinity)}$$ Rearranged, this series looks like: $$S = \left(1 - \frac12\right) - \left(\frac14\right) + \left(\frac13 - \frac16\right) - \left(\frac18\right) + \left(\frac15 - \frac1{10}\right) - \left(\frac1{12}\right) + \left(\frac17 - \frac1{14}\right) \ldots\text{(to infinity)}\\ S = \left(\frac12\right) - \left(\frac14\right) + \left(\frac16\right) - \left(\frac18\right) + \left(\frac1{10}\right) - \left(\frac1{12}\right) + \left(\frac1{14}\right) \ldots\text{(to infinity)}$$ This rearranged infinite series contains every number that the original infinite series had. Further, $$ 2S = 1 - \frac12 + \frac13 - \frac14 + \frac15 - \frac16 + \frac17 - \frac18 + \frac19 - \frac1{10} + \frac1{11} - \frac1{12} \ldots\text{(to infinity)}$$ Thus: $2S = S$ $2 = 1$ Mathematics disproven. Sorry. Jokes aside, I know that infinite series can be calculated in different ways to get different results. My question is: Why? While it makes sense with Grandi's and similar series, it doesn't make sense to me for a series whose final term is $\frac1\infty = 0$. | I don't understand that why the terms of an absolutely convergent series can be rearranged in any order and all such rearranged series converge to the same sum. my textbook gives me an example that it is not so for conditionally convergent series $1-\frac12+\frac13-\frac14+\ldots=\ln2$ $1+\frac13-\frac12+\frac15+\frac17-\frac14+\frac19+\frac1{11}-\frac16...=\frac32\ln2$ which I also don't know how to prove |
I'm reading Hardy's wonderful book on theory of numbers. At some point he is proving that "almost all" integer numbers contain digit 9 (or any other sequence of digits, like "9345"). It's fairly obvious: number of integers up to $n$ digits is $a_n=10^n-1$. Number of integers up to $n$ digits with digit 9 missing is $b_n=9^n-1$. And because $\lim_{n\to\infty}{b_n}/{a_n}=0$ it means that $b_n \ll a_n$ for big enough $n$. In other words, the number of integers without digit 9 is "neglectable" (comparatively small). So far so good, but in the footnote Hardy mentiones an interesting consequence without proof. Let $n$ be any number that is missing decimal digit 9. The following "quasiharmonic" sum is convergent: $$\sum_{n=1}^{\infty}\frac 1n=\frac11+\frac12+\dots+\frac17+\frac18+\frac1{10}+\frac1{11}+\dots\frac1{18}+\frac1{20}+\frac1{21}+\dots$$ It also means that the sum of reciprocals of all numbers containing digit 9 must be divergent: $$\frac19+\frac1{19}+\frac1{29}\dots+\frac1{89}+\frac1{90}+\frac1{91}+\frac1{92}+\dots$$ Is there a simple proof for this? | I know that the harmonic series $1 + \frac12 + \frac13 + \frac14 + \cdots$ diverges. I also know that the sum of the inverse of prime numbers $\frac12 + \frac13 + \frac15 + \frac17 + \frac1{11} + \cdots$ diverges too, even if really slowly since it's $O(\log \log n)$. But I think I read that if we consider the numbers whose decimal representation does not have a certain digit (say, 7) and sum the inverse of these numbers, the sum is finite (usually between 19 and 20, it depends from the missing digit). Does anybody know the result, and some way to prove that the sum is finite? |
Given $p(x)$ is a polynomial with integer coefficients and that $p(a)=1$ for some integer $a$ prove that $p(x)$ has no more than two integral roots. I've attempted a proof by contradiction assuming $p(x)$ has three or more roots, but haven't gotten anywhere on this. Help would be appreciated! | The question that I am trying to answer is : Suppose is $p(x)$ is a polynomial with integer coefficients. Show that if $p(a) = 1$ for some integer a then $p(x)$ has at most two integer roots. I have no idea how to get started. Any help would be awesome! |
I have 6GB RAM and 10GB swap. Some applications dare to consume/allocate/use about 5GB to 6GB of RAM. When the memory completely fills out, the whole system hangs for 1 to 2 minutes to swap all inactive (and active) appplications, what is really troublesome because to access again some simple applications that consume less than 100MB, I have to wait about 10s to it be put on RAM again (well, all that is how I see it works out of my usage experience). So, my goal is: put that single application under leash, restrict it to keep the whole system fast and stable. | /proc/sys/vm/swappiness is nice, but I want a knob that is per process like /proc/$PID/oom_adj. So that I can make certain processes less likely than others to have any of their pages swapped out. Unlike memlock(), this doesn't prevent a program from being swapped out. And like nice, the user by default can't make their programs less likely, but only more likely to get swapped. I think I had to call this /proc/$PID/swappiness_adj. |
I have to use the same switch case repeatedly in different functions. In different functions, the switch case definition will be different. For example: int groupID = somenumber; private void FunctionA() { switch (groupID) { case 0: // Do Action A break; case 1: // Do Action B break; case 2: // Do Action C break; } } private void FunctionB() { switch (groupID) { case 0: // Do Action Z break; case 1: // Do Action X break; case 2: // Do Action Y break; } } Is that any method to use the same switch case once time but the definition can be different? | What are the ways to eliminate the use of switch in code? |
class vehicle{ ... }; class motorVehicle: virtual public vehicle{ ... }; class twoWheels: virtual public vehicle{ ... }; class motorcycle: public motorVehicle, public twoWheels, virtual vehicle{//(1) .... }; (1) Why does class motorcycle has to inherit class vehicle, when it is already contained in classes motorVehicle and twoWheels? In the explanation from the book it is written that class motorcycle has to inherit class vehicle in order to make sure that the constructor of the base class (vehicle) will be called. If this explanation is correct, I don't understand why it says "virtual vehicle"? What type of inheritance is this? | I want to know what a "virtual base class" is and what it means. Let me show an example: class Foo { public: void DoSomething() { /* ... */ } }; class Bar : public virtual Foo { public: void DoSpecific() { /* ... */ } }; |
I have an javscript object finalTitleList =[{"Title":"ffd","Iscompleted":"","Id":0}, {"Title":"fdfmdbk","Iscompleted":"","Id":1}, {"Title":"fdf,d","Iscompleted":"","Id":2}] Suppose i like to delete an 2nd item using delete finalTitleList[1], after deletion it delete the item but length is not updated(snapshot attached: contain only 2 item but showing length 3). So when i am adding that object in localstorage using localStorage.setItem("TaskTitleList16", JSON.stringify(finalTitleList)); On place of deleteditem it shows null. I want to completely remove that item, please help me. | What is the difference between using on the array element as opposed to using ? For example: myArray = ['a', 'b', 'c', 'd']; delete myArray[1]; // or myArray.splice (1, 1); Why even have the splice method if I can delete array elements like I can with objects? |
I would like two of my lemmas to be numbered additionally by letters, e.g. Lemma 2a. and Lemma 2b, while the all other lemmas (and theorems etc.) are numbered normally by numbers. \newtheorem{lemma}{Lemma} \begin{document} \begin{lemma} This should be Lemma 1. \end{lemma} \begin{lemma} This should be Lemma 2a. \end{lemma} \begin{lemma} This should be Lemma 2b. \end{lemma} \begin{lemma} This should be Lemma 3. \end{lemma} \end{document} Duplicate, I guess: tex.stackexchange.com/q/43346/4427 | I am trying to number my theorems as follows: Theorem 1.A. First part of a theorem. Theorem 1.B. Second part of the theorem. Theorem 2. A theorem with no parts. The following almost works: \newtheorem{theorem}{Theorem} \newtheorem{theorempart}{Theorem}[theorem] But it does not increment the theorem counter as I want, so that \begin{theorempart}First part of a theorem. \end{theorempart} \begin{theorempart}Second part of the theorem. \end{theorempart} \begin{theorem}A theorem with no parts. \end{theorem} gives: Theorem 0.1. First part of a theorem. Theorem 0.2. Second part of the theorem. Theorem 1. A theorem with no parts. Also, I don't know how to get the part-number to be a letter instead of a number. I am using MiKTeX. |
So I read a book back in school (2000s), didn't finish it for whatever reason, and have been unable to remember the name or anything outside of a few small details. Note, it's not Ender's Game or The Giver. The details I know are: Main characters are boys aged 8-17ish. They're raised in a school/facility of sorts where everything adheres to a strict schedule. They sleep in 'pods' and have very little freedom. The main boys (I forget but I think there are 2-3) want to escape or to at least see the outside world. When they try to do so, the 'teacher' of sorts (as well as a security team) go after them. The teacher is an ex-soldier or special force unit, as when he gets hit in the face and his nose is broken, he is able to mentally move the pain around. As in, concentrate and move it from his broken nose to another part of his body to 'deal with later', so he can continue to chase after the boys. That's all I have, but I would really appreciate any help! I've been looking for years. :( | I can't really remember how long ago it was, but I think the book was marketed towards children/teens. All I remember is the basic premise of the story. Some story about these unusual little blue electric critters that only certain people could see, and these kids took it upon themselves to go about destroying them since they fed off energy or something like that. Not sure whether they fed off people or off electricity... or both maybe? I think the dominant method of destroying them was an electric baton that was taken from law enforcement. I wanna call them buzz batons, but that's probably thanks to Artemis Fowl. |
There are two dictionaries (d1 and d2) formed after combining list values. I have to subtract the values (d2-d1) and print the dictionary. d1 = {'Rash': '80000000', 'Kil': '80000020', 'Varsha': '80000020', 'sam': '80010000'} d2 = {'Varsha': '8000ffe0', 'sam': '80014000', 'Kil': '8000ffe0', 'Rash': '801fffff'} d3 = {key: d2[key] - d1.get(key, 0) for key in d2} print(d3) This is not working as it is giving type error: TypeError: unsupported operand type(s) for -: 'str' and 'str' | How do I convert a hex string to an int in Python? I may have it as "0xffff" or just "ffff". |
Long listings are only partially shown since the amount of lines remembered isn't too large. I'd like to cancel the limit of lines in a similar way to the following: only I'm running an Ubuntu Server 15.10 and I'd like to do it using CLI. I've also tried to use xrandr from the x11-xserver-utils package, but I keep getting Error: Can't open display: when running it, or when running xvidtune. I tried using a Terminal Multiplexer, but neither screen nor tmux did the trick (admit I'm not sure I took full advantage of tmux though), and setting the GRUB_CMDLINE_LINUX value did not change anything either. I've tried 1024k, 2048k etc, but nothing happend - the amount of lines remains limited. To do the above said, I've tried to use information from the following: , and , by following the links given by commentators and those who submitted their answers - I still haven't solved it, but thanks a bunch for that, guys. NOTICE 1 One thing that did happen, is after changing the lines value with the screen Terminal Multiplexer to a large value (65000) - the screen refreshed badly. I saw white lines whenever I typed something. So I guess it did affect RAM consuming, but the amount of lines did not change. NOTICE 2 I installed Ubuntu-Server 14.04.3 for reference - and most methods above work. I was able to send settings to the kernel through fbcon and set the "lines-history" file size to what ever I wanted, for example. Ideas? | I can see only limited lines on terminal by using shift+ pageup. in Ubuntu desktop version, there is option to make scroll-back lines unlimited. how to do it in Ubuntu server version. please suggest. |
In my course of algorithms we talk about time complexity with Big O Notation. And I am always confused when I try to calculate the Big O. I know for example when a function then it can be O(n) or O(n²). But I don't know the logical background and how to get this solution for each function. int func1(int n){ for (int i=1; i<n; i=i*2) printf("i = %d", i); return i; } int func2(int a, int b) { int result=1; while (b>0) { result = result*a; b = b-1; } return result; } void func3(int n) { for (int i=0; i<pow(2,n); i++) printf("%d", i); } | Most people with a degree in CS will certainly know what . It helps us to measure how well an algorithm scales. But I'm curious, how do you calculate or approximate the complexity of your algorithms? |
It's Linux and everything should be setup manually, but I'm new to this and need help in setting up my WiFi. here's what I did. I installed ubuntu, tried to connect the WiFi while installation it didn't got connected, I thought well it'll connect once it got installed but it still isn't connected. I think it should be pretty easy to solve, something I forgot to tick or something a thing to notice is that it says it's connecting for few seconds and doesn't get connected after that | My Panda USB wi-fi adapter works just fine on 16.10, but when I try to connect to my wi-fi router in 17.04, GNOME network manager reports "Connection failed." I did some tinkering, and noticed that my MAC address for my wifi adapter, according to GNOME, is DIFFERENT every time I make it forget my wifi settings and try to reconnect. Any leads on a possible fix or work-around? I'm running Ubuntu GNOME 17.04, kernel 4.10.0-19-generic, GNOME 3.24.0. |
Hi I am looking for a word or phrase that suggests there are three options, and maybe a word that means there are 4 options. Something that can be used in writing rather than conversation. | I was surprised to discover my dictionary had this entry for dilemma: a situation in which a difficult choice has to be made between two or more alternatives, esp. equally undesirable ones The notion of dilemma meaning two or more flies against what I was taught about the word. The very idea of a is specifically based on the number two. Has my dictionary merely updated its definition to encapsulate the many people who use dilemma for more than two equal choices? Or was someone in my youth being unnecessarily pedantic? |
In , the Mini View feature is introduced: I'm particularly interested in this feature, but I don't know how to get it to work. For example, in Groove music, I don't see an option for switching to mini view. So, how do I use this feature? Attribution: Image appears to be copied from | I have found several news sites that say that Windows 10 Anniversary update could bring PIP mode for Windows 10. Here is one article from which says the following (Published April 13, 2016) Microsoft could add a new feature called “Picture in Picture” for Windows 10. The update will most likely land with Windows 10 Anniversary Update and the tech company hinted at it in its official roadmap for Windows 10. This is an image that shows what PIP mode looks like Is this feature available yet and if so how can I use it? With Windows 10 built in features or using third party software, is there a way that I can get PIP mode in Windows 10? My overall goal is to watch instructional videos in a mini view while I do programming tasks or even play games on the same screen (I use a 55" TV). |
What's the recommended torque of the front caliper bolt for a carbon fork? The Fork is from a Felt F1. I don't want to damage the fork from over thightening. | I've recently got a new bike with a . This comes with deep-drop calliper brakes (Shimano R451 Dual Pivot). The first time out I bumped one of the brakes and it twisted around the single attachment bolt and rubbed on the rim. I managed to easily twist it back by hand and carry on, however I thought the bolt probably needs tightening. The question is: How tight can it be? As the fork is part carbon I've so far only dared to take it up to 4Nm, but it still seems possible to twist the whole calliper around with a bump of the hand. Maybe that's normal? Perhaps it's easier to bump around because of the longer deep-drop lever. Should I be aiming to get it really secure? I'm not sure whether the brake mount in the fork is all carbon, or some of it is alloy underneath, but either way I'd like to know what a sensible torque is. As far as I can see from the there is no such specification. How can I find this out? |
cubic equation: $$ax^3+bx^2+cx+d=0$$ Cube means 3. Quadratic equation: $$ax^2+bx+c=0$$ Quad means 4. But it is a power of two, should it be called bi... Equation. My question is: Is this a mistake in naming the quadratic equation? | Why is it called a quadratic if it only contains $x^2$, not $x^4$? Should it not be bidratic or didratic etc? |
I am trying to get the list of last 10 accounts viewed. The code seems to be working in sandbox and workbench but when I try deploying it in production, I get the error: No such column 'LastViewedDate' on entity 'Account'. SELECT Id, Name, LastModifiedDate FROM account WHERE LastModifiedDate !=null ORDER BY LastViewedDate DESC limit 10 <apiVersion>31.0</apiVersion> Attached the error messags | How how do I query recent account views and group by LastViewedDate SELECT Id, Name FROM Account ORDER BY Name DESC limit 10 FOR VIEW I used to have it like this, but my test case is keep failing SELECT SELECT Id, Name, LastModifiedDate FROM account WHERE LastModifiedDate !=null ORDER BY LastViewedDate DESC limit 10 static testmethod void testOppExt_TestMethod(){ Opportunity testOpp = new Opportunity(Name = 'TestOpp', StageName='Test', CloseDate = Date.today()); insert testOpp; Account testAcc = new Account(Name = 'Test Account'); insert testAcc; Contact con = new Contact(LastName='Test',AccountId=testAcc.id); insert con; Test.startTest(); OppExt testCon = new OppExt(); Contact conn = testCon.contact; Account Accn = testCon.acc; Test.stopTest(); } Error Message Component Errors API Name Type Line Column Error Message 0 0 , Details: Average test coverage across all Apex Classes and Triggers is 0%, at least 75% test coverage is required. 0 0 SiteRegisterControllerTest.null(), Details: line -1, column -1: Previous load of class failed: oppext null 0 0 SiteLoginControllerTest.null(), Details: line -1, column -1: Previous load of class failed: oppext null 0 0 SiteRegisterController.null(), Details: line -1, column -1: Previous load of class failed: oppext null 0 0 testnewOpportunityController.null(), Details: line -1, column -1: Previous load of class failed: oppext null 0 0 SiteLoginController.null(), Details: line -1, column -1: Previous load of class failed: oppext null 0 0 testOppExt.null(), Details: line -1, column -1: Previous load of class failed: oppext null 0 0 OppExt.null(), Details: line 32, column 17: No such column 'LastViewedDate' on entity 'Account'. If you are attempting to use a custom field, be sure to append the '__c' after the custom field name. Please reference your WSDL or the describe call for the appropriate names. null |
When heating oil sometimes I notice smoke comes out and this sets home smoke detector off. At this point I lower the fire or just add food. Does this mean that it's already hit the smoking point and the oil should no longer be used? If it hits smoking point and we lower the temperature is it still ok to use or is it only a problem with reuse? | Teflon toxicity and second degree burns aside, are there any health issues related to cooking with oil at or past its smoking point? Googling a bit I found one article that went so far as to say you should always "discard oil that's reached its smoke point, along with any food with which it had contact". Other searches showed pages suggesting cancer risks. I've never given it a thought before and I often use peanut oil at smoking point to brown meat. |
I am trying to print from an Illustrator file and my items with gradients/shadows look fine on screen but when printed I get a faint white box. What setting am I missing?? | I apologize in advance if this has been asked, but I've searched for a few phrases and I'm not sure how else to ask it. Using InDesign I've created a vector "ribbon" and given it a drop shadow. I've also placed a PSD file with a transparent background on the document. On screen, the exported PDF and the InDesign screen preview look perfect (View > Overprint Preview is enabled). Here is a screenshot of the exported PDF (v1.5): When printed on my HP LaserJet 2600n, however, I get these god-awful blocks around the shadow of the ribbon object and the placed PSD file. Here is a photo of the printed page (the camera on my phone washed out the image - it is accurately reproducing the colours): I've tried converting Spot colours to Process in case the printer was experiencing some issue with the Pantone colours, but the colours are actually printing fine, it seems to be the placed file and the shadow causing issues. I'd love to learn how to fix this, and more importantly - what causes the issue! |
I'm trying to install skype using but after it installs it just opens up a blank skype application and the playonlinux wizard keeps loading (Says please wait) forever. Anyone have any idea what could be the problem ? :) | I want to install Skype, but I can't locate it in Software Center or by using Synaptic Package Manager. Can anyone help me? |
I m using the latest Parrot OS. I would like to install the Ubuntu Software Center, so that I can install/uninstall my packages easily. Is it possible to install the Ubuntu Software Center on Parrot OS? | I followed the instructions for installing kali linux and put these commands into the terminal: apt-get update apt-get install software-center I also added: deb http://http.kali.org/ /kali main contrib non-free deb http://http.kali.org/ /wheezy main contrib non-free to my sources list. When I start up the software center a tab appears in the tool bar menu titled "starting software center" a seconds later it just closes. No window comes up or anything the tab just closes. This appears in terminal when I type sudo software-center: root@MattJones:~# sudo software-center Traceback (most recent call last): File "/usr/bin/software-center", line 131, in <module> from softwarecenter.ui.gtk3.app import SoftwareCenterAppGtk3 File "/usr/share/software-center/softwarecenter/ui/gtk3/app.py", line 49, in <module> from softwarecenter.db.application import Application File "/usr/share/software-center/softwarecenter/db/application.py", line 27, in <module> from softwarecenter.backend.channel import is_channel_available File "/usr/share/software-center/softwarecenter/backend/channel.py", line 25, in <module> from softwarecenter.distro import get_distro File "/usr/share/software-center/softwarecenter/distro/__init__.py", line 179, in <module> distro_instance=_get_distro() File "/usr/share/software-center/softwarecenter/distro/__init__.py", line 162, in _get_distro module = __import__(distro_id, globals(), locals(), [], -1) ImportError: No module named Kali Does anyone know what the problem might be? |
In a MCMC implementation of hierarchical models, with normal random effects and a Wishart prior for their covariance matrix, Gibbs sampling is typically used. However, if we change the distribution of the random effects (e.g., to Student's-t or another one), the conjugacy is lost. In this case, what would be a suitable (i.e., easily tunable) proposal distribution for the covariance matrix of the random effects in a Metropolis-Hastings algorithm, and what should be the target acceptance rate, again 0.234? Thanks in advance for any pointers. | In a MCMC implementation of hierarchical models, with normal random effects and a Wishart prior for their covariance matrix, Gibbs sampling is typically used. However, if we change the distribution of the random effects (e.g., to Student's-t or another one), the conjugacy is lost. In this case, what would be a suitable (i.e., easily tunable) proposal distribution for the covariance matrix of the random effects in a Metropolis-Hastings algorithm, and what should be the target acceptance rate, again 0.234? Thanks in advance for any pointers. |
I am trying to make a simple linked list, and I came across a LNK2019 when I started to add code to my main function. It was compiling before, but when I added code to my main, I got several errors. I have all my header files included in my main CPP file, and I checked for circular includes. I haven't used C++ in a while, so sorry if this seems obvious. I went with the precompiled headers option when I made the project, if that means anything. What am I messing up? Errors: 1>RandomCPP.obj : error LNK2019: unresolved external symbol "public: __thiscall List<int>::List<int>(void)" (??0?$List@H@@QAE@XZ) referenced in function _wmain 1>RandomCPP.obj : error LNK2019: unresolved external symbol "public: __thiscall List<int>::~List<int>(void)" (??1?$List@H@@QAE@XZ) referenced in function _wmain 1>RandomCPP.obj : error LNK2019: unresolved external symbol "public: void __thiscall List<int>::add(int const &)" (?add@?$List@H@@QAEXABH@Z) referenced in function _wmain 1>RandomCPP.obj : error LNK2019: unresolved external symbol "public: int * __thiscall List<int>::get(int)const " (?get@?$List@H@@QBEPAHH@Z) referenced in function _wmain List.h: #pragma once #include "ListNode.h" template<class T> class ListNode; template<class T> class List { public: List<T>(); ~List<T>(); void add(const T&); void insert(int, const T&); void clear(); bool isEmpty() const; T* get(const int) const; int getLength() const; void foreach(void(*foo)(T)) const; T* operator[](const int index) const; private: ListNode<T>* firstElement; ListNode<T>* lastElement; //Utility ListNode<T>* getNewNode(const T&); ListNode<T>* getNode(int index) const; }; ListNode.h: #pragma once template<class T> class List; template <class T> class ListNode { friend class List < T > ; public: ListNode(const T& data); ~ListNode(); T getData() const; private: T data; ListNode<T> *nextPtr; }; RandomCPP.cpp (Main File): #include "stdafx.h" #include "List.h" #include "ListNode.h" using namespace std; int _tmain(int argc, _TCHAR* argv[]) { List<int> values = List<int>(); values.add(0); values.add(1); values.add(2); values.add(3); values.add(4); cout << values.get(0) << endl << values.get(1) << endl << values.get(2) << endl << values.get(3) << endl << values.get(4) << endl << endl; system("pause"); return 0; } stdafx.h: #pragma once #include "targetver.h" #include <stdio.h> #include <tchar.h> #include <iostream> I have a List.cpp file and a ListNode.cpp file, each of which contain the definitions of the class declared in the corresponding .h file, and nothing else. The stdafx.cpp file is empty except an include of stdafx.h. | 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.) |
I was trying to make a presentation using beamer, when suddenly I got the following error message: I don't know why it does this, because I've never had to use sansmathaccent before. I tried running old files that used to be fine, however they get the same error message now as well. Even the most simple of files: \documentclass{beamer} \begin{document} \frame{Hello $A$} \end{document} gets the error message. What is/could be going on? N.B. I recently (two days ago) ran an update for all my packages. Could this have something to do with it? Edit: By now I've installed both sansmathaccent and filehook because the error message said so. Now it shows this error: !pdfTeX error: pdflatex.exe (file mathkerncmssi8): Font mathkerncmssi8 at 450 n ot found ==> Fatal error occurred, no output PDF file produced! as soon as you include any maths to the document. Note If i type Hello $\mu$ everything is fine. Ordinairy letters are causing trouble. | I get the following error when I try to typeset a beamer document. kpathsea: Running mktexpk --mfmode / --bdpi 600 --mag 0+525/600 --dpi 525 mathkerncmssi8 gsftopk: fatal: map file `cid-base.map' not found. mktexpk: don't know how to create bitmap font for mathkerncmssi8. mktexpk: perhaps mathkerncmssi8 is missing from the map file. kpathsea: Appending font creation commands to missfont.log. ) !pdfTeX error: pdflatex (file mathkerncmssi8): Font mathkerncmssi8 at 525 not found ==> Fatal error occurred, no output PDF file produced! But if I remove sansmathaccent.sty from the TeX Live tree, the document typesets fine. Here is a minimal working example. \documentclass[10pt]{beamer} \begin{document} \begin{frame}{A very short beamer document} $e^{i\pi}+1=0$ \end{frame} \end{document} |
Though I am new to Blender, I am not new to modeling. Still there is one thing I am not finding in Blender 2.8 beta, and it's frustrating the hell out of me. How the heck do I change the properties of a primitive during creation. In Blender 2.79 I see the option to do this, during creation, in the bottom left corner of the screen, but I do not see it in 2.8. For example, with the selector icon chosen, which seems to be the default upon opening, I go to Add > Mesh > Cylinder. The cylinder shows up on the screen, but I cannot find the properties to change the number of vertices/facets, the radius, the height, etc. Am I doing something wrong? Thank you, Jim | The tutorial I read is based on 2.79. So I'm not sure if it's still the same name in 2.8. But I can't find anything providing similar functionalities. |
As we know, the integral of function $f:[a,b]\to \mathbb{C}$ is defined $$ \int\limits_a^bf(t)\,\mathrm{d}t=\int\limits_a^b\operatorname{Re}[f(t)]\,\mathrm{d}t\,+\,i \int\limits_a^b\operatorname{Im}[f(t)]\,\mathrm{d}t$$ But, I am curious to know how we defined this integral in this way? Why? As integral of any function $g:[a,b]\to \mathbb{R}$ measures area. But I also want to know what the integral of $f$ measures? | In normal line integration, from what I understand, you are measuring the area underneath $f(x,y)$ along a curve in the $x\text{-}y$ plane from point $a$ to point $b$. But what is being measured with complex line integration, when you go from a point $z_1$ to a point $z_2$ in the complex plane? With regular line integration I can see $f(x,y)$ maps $(x,y)$ to a point on the $z$ axis directly above above/below $(x,y)$. But in the complex case, when you map from the domain $Z$ to the image $W$, you are mapping from $\mathbb{R^2}$ to $\mathbb{R^2}$ ...it is not mapping a point to 'directly above/below'...so I don't have any intuition of what is happening with complex line integration. |
NB The following is a community-generated list of websites that republish Stack Exchange content without attributing it properly. It is no longer being maintained, because the procedure for reporting such sites has changed; see the duplicate for more information. There are a number of license-violating clones of Stack Exchange sites popping up that use Stack Exchange's data without following our Creative Commons attribution terms. Those terms are , and are also included as a .txt file in every data dump we produce. Google now has in search results. Also, you can : The option to block a site appears when you click a search result and then navigate back to the search results page. Click the "Block" link next to that result to block all pages within the site's entire domain. This post was created as an attempt to organize information originally posted . You may also be looking for . | of Stack Overflow, all content posted on Stack Exchange sites by their users (i.e. you wonderful people) has been provided to the whole universe under . For my fellow non-lawyers, that license basically means: Anyone can use any Stack Exchange posts at any time without having to ask for permission Making money off of the copied content is permitted You don't even have to copy stuff from here verbatim; you can just use it as a starting point and make whatever edits you want There are just two rules you have to follow: You have to provide . Simple links to the original post and author info are just fine. You have to and allow other people to use your content, as long as they follow these very same rules. How meta! (If you ever forget any of that, and want to refresh your memory, the license info is linked to in the footer of every page.) There are, in fact, a lot of people who republish varying amounts of our content for assorted reasons. Unfortunately, there are some Stack Content Republishers Attributing Poorly and/or Excelling at Ranking (SCRAPERs, for short). In this context, "attributing poorly" means any use that doesn't follow our attribution rules or make any other reasonable attempt at give credit. This can get pretty egregious; I've seen SCRAPERs that not only don't link back to SE originals, but also use fake author info and post dates to make it harder to find originals. By "excelling at ranking," I'm referring to copycat sites that end up higher in Google results than the original SE sites do for the same content. That's not necessarily wrong, but in some cases, it indicates inappropriate SEO hackery. So, the question is: what can you do if you spot a SCRAPER? |
I'm trying to print how many time a substring occurs. When I try to print this I get the error- Counter is undefined. s = str("eewd") substring = "e" def count_substring(s,substring): len1 = len(s) len2 = len(substring) i =0 counter = 0 while(i < len1): if(s[i] == substring[0]): if(s[i:i+len2] == substring): counter += 1 i += 1 return counter if __name__ == "__main__": print(counter) Also is if __name__ == "__main__": needed in python 3? | What exactly are the Python scoping rules? If I have some code: code1 class Foo: code2 def spam..... code3 for code4..: code5 x() Where is x found? Some possible choices include the list below: In the enclosing source file In the class namespace In the function definition In the for loop index variable Inside the for loop Also there is the context during execution, when the function spam is passed somewhere else. And maybe pass a bit differently? There must be a simple reference or algorithm somewhere. It's a confusing world for intermediate Python programmers. |
I was wondering if it is possible to install and play Steam games like Skyrim off a Linux or Unix-base Operating System (OS), such as FreeBSD or OpenSUSE? Update: Apart from installing through Wine, which is an emulator and would hence defeat the purpose, because it would cancel out any performance increase you might get over running through Windows. In short (as far as I am aware), running through Wine would give even less performance than running through Windows. | Ok, I was kind of surprised that this hadn't been asked here before, but maybe it's too technical for this site. You guys decide. I've heard lots of different stories about setting up Wine on Ubuntu, WineTricks, PlayOnLinux etc., but never a 'This is the best way to do it for Steam and Steam games' thread. So has anyone had any real success getting their Steam games to run on Ubuntu through Wine or something similar? If so, could we get some specific steps? |
Currently, to switch from a main site to its meta (and vice versa), one needs to search for the other site in the side bar. I think we can make the process more convenient of the switch button is included in the drop down on the question lists. | Currently, the only way I know of to visit a site's meta via the Android app (1.0.16) is to pin its meta to my sites in the sidebar. It's a really good thing I can do this for the metas I visit frequently, and I don't want to see it go, but it's also inconvenient if it's the only way to reach a meta. Could we have a sidebar item that takes us to the meta site for whatever SE site we currently have open? (Or, if we're already in their meta, to their main site) To illustrate my point, here's a before & after: |
I heard on the internet that defragmenting an SSD is quite harmful. I was wondering if it is true, and if so, why? I've already done it a few times and it didn't seems to be broken at all. | I keep hearing that this is a huge no-no. Why is this? I run Ubuntu mostly so it doesn't affect me, but I was just wondering. |
I am trying to install Windows 7 Pro x86 patch kb4012212 / 5 for Ransomware security But not able to install ,errors occurs of "The Update is not applicable to your Computer". So Please help me to install this patch file to my system. or Is their any other patch file require before this installation. | Running Windows 7 Professional. It appears that the proper patch/update for me to protect against the wannacrypt virus is KB4012215. I reviewed my Windows Update history and see that I tried to install that update on 3/18/17 but the installation "failed." I right-clicked on it and the Error Code is 80070020. Questions: Is KB4012215 the proper update to guard against wannacrypt? If not, please tell me the proper update and where and how to download and install it. If so, please tell me where and how to download and install it. Thank you. |
Why we define the variance of a random variable $X$ as $\text{var}[X]=\text{E}[(X-\mu)^2]$ instead of $\text{var}[X]=\text{E}[\left|X-\mu\right|]$. Normally we understand the standard deviation $\sigma=\sqrt{\text{var}[X]}$ as a measure of the average distance of a sample from the mean. If this is the case, isn't it more reasonable to use the absolute value instead of squaring as a measure of distance? Then this way we don't have to square afterwards to obtain $\sigma$. | Let's take the numbers 0-10. Their mean is 5, and the individual deviations from 5 are -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5 And so the average (magnitude of) deviation from the mean is $30/11 \approx 2.72$. However, this is not the standard deviation. The standard deviation is $\sqrt{10} \approx 3.16$. The first mean-deviation is a simpler and by far more intuitive definition of the "standard-deviation", so I'm sure it's the first definition statisticians worked with. However, for some reason they decided to adopt the second definition instead. What is the reasoning behind that decision? |
Hello i trying to select result date from mysql mytable: id_room | check_in | check_out The problem is when i want to check reserved data betwwan date 1 to date 2. for example my room data: id_room : 1 ; check_in : 2014/11/01 ; check_out : 2014/11/08 So i want to check my booking in, 2014/11/03 and 2014/11/04. In system its will be not resulted thats mean no booking in that date, but in actual life 2014/11/03 and 2014/11/04 must have been booked. Because im check_in in 2014/11/01 and check_out in 2014/11/08. I'm using SELECT * FROM tabel WHERE cek_in BETWEEN '2014/11/03' AND '2014/11/04' OR cek_out BETWEEN 2014/11/03' AND '2014/11/04' So if there any clue or other logic, please please tell me :D Thanks | Given two date ranges, what is the simplest or most efficient way to determine whether the two date ranges overlap? As an example, suppose we have ranges denoted by DateTime variables StartDate1 to EndDate1 and StartDate2 to EndDate2. |
I asked a similar question yesterday about well ordered sets, now I am having troubles with equivalence relations. Could someone suggest an injection from a well known set of cardinality $2^{\aleph_{0}}$ to the set of all equivalence relations of $\mathbb{N}$? Many thanks in advance! | I came across this long proof on this site: But I would like to know whether my direction can work. Say we want to find the cardinality of all equivalence relations in $\mathbb{N}$. Since it is a subset of all relations in $\mathbb{N}$, I conclude it has a cardinality smaller or equal to $\aleph$. Now, define an injective function from $P(\mathbb{N})$ to the set of equivalence relations by matching each subset of $\mathbb{N}$ with the identity relation (which is an equivalence relation in $\mathbb{N}$. Therefore the cardinality of all equivalence relations in $\mathbb{N}$ is greater or equal to $\aleph$ and using CSB we get the desired result. Seems legit? |
I have Ubuntu desktop. How do I install LAMP to run on it or can I? | I set up a new VPS instance of Ubuntu and am wondering what the easiest way is to get up and running with a basic LAMP stack (i.e. which packages are required, which configuration options need to be tweaked, if any, etc.). |
Can I tab multiple lines of code in stack overflow? When I copy and paste code into the code sample part, the alignment throughout the code is usually always off. | Possible Duplicate: When writing code in SO, I always press Tab to indent my code. It doesn't work. Instead, I lose focus on the question text area. To actually indent, I use Spacebar, but doing this to many lines of code is annoying. What is the right way to indent code? |
I have the shell script which opens Firefox and launches macros in it (I use a Firefox add-on called Imacros to create macros). The content of my shell script named house.sh is like that: firefox imacros://run/?m=house.iim And I created a scheduled job via crontab -e to run that script hourly every day: 47 * * * * /home/meerim/bin/house.sh But nothing happened (Firefox didn't open). Then I tried this: 47 * * * * env DISPLAY=:0.0 /home/meerim/bin/house.sh But it didn't solve the problem. So how should I fix it? My house.sh script works properly when I run it from terminal. | Once upon a time, DISPLAY=:0.0 totem /path/to/movie.avi after ssh 'ing into my desktop from my laptop would cause totem to play movie.avi on my desktop. Now it gives the error: No protocol specified Cannot open display: I reinstalled Debian squeeze when it went stable on both computers, and I guess I broke the config. I've googled on this, and cannot for the life of me figure out what I'm supposed to be doing. (VLC has an HTTP interface that works, but it isn't as convenient as ssh.) The same problem arises when I try to run this from a cron job. |
I am trying to use ifdown command on my network interface (enp0s3), but it claims, that this interface is not known. When I try the same command with my loopback lo it works fine. What could be the problem ? My network-manager is sure off, only networking daemon is running. lsb_release -d Ubuntu 18.04.1 LTS cat /etc/netplan/50-cloud.init.yami You should probably know, it is on VM. | Starting sometime around Ubuntu 18.04, the Ubuntu devs stopped using the classic /etc/init.d/networking and /etc/network/interfaces method of configuring the network and switched to some thing called . This has made a lot of people very angry and been widely regarded as a bad move. Is it possible to remove netplan and use the correct /etc/network/interfaces method for configuring the network? |
The question is to work out the number of semi-direct products for from Q to H, where $$ H = C_{42} , Q = C_{3} $$ I did: $Aut(C_{42}) = C_2 \times C_6 = C_{12}$ 3 divides 12 telling us that they're are some semidirect products. If we let Q = (1, 2, 3). We can see that they're are 3 elements in Q (1, 2 and 3) that divide 12, thus there are 3 semi direct products. Is this correct reasoning? | There is a semi direct product if you go $\theta: Q \rightarrow Aut(H)$. $H = C_{17}, Q = C_2$. $Aut(H)\cong C_{16}$. From here, how do I construct the semi direct products? I said, in $C_{16}$, there are two elements of order that divide $2$, which are $1$ and $2$. Therefore there are two semi direct products. Also $17 \times 2 = 34$ tells me that in both semi direct products there will be $34$ elements. How do I construct the semi direct products from here though? |
Good day. Today I was just working when I saw that there was a snowflake in the top-bar-menu, and it had a purple notification number on it. I had never seen it before. Note: This has been solved now. Is this a new StackExchange Meta feature? Or was it there already? What does it do? The tooltip for this literally says Winter Bash. What is Winter Bash? Thank you. Note: This is not a duplicate of That is simply a feature request asking for a (new) better tooltip for the snowflake icon. Note: This has been solved now. | I tried to write , but I couldn't find any simple explanation page to link to. I ended up garbling a home-spun description of my own with a not-terribly-helpful image from 2012. This puts it better than I can: As a new user in 2015 can there please be more information about what is WinterBash. The link took me to a bunch of stick figures running around making (I think) numbers (I think its a countdown clock). It doesn't explain the event or even what a hat is. – Ian Miller Dec 4 at 2:58 All I found on Meta was dead links. For example, was downvoted to -2 and answered with a link to an FAQ page that no longer exists. |
I want to calculate $ \lim_{n \to \infty }{\frac{{[n(n+1)(n+2)...(2n-1)]}^\frac1n}n} $ using $$\int_0^1 f(x)\,dx=\lim_{n\to\infty}\frac1n \sum_{k=1}^n f\left(\frac{k}n\right)$$ I know I have to convert $\frac nk$ to $x$, but I am confused since all the factors are multiplied together. Should I use $\log$? | Evaluate $$\lim_{n \rightarrow \infty~} \dfrac {[(n+1)(n+2)\cdots(n+n)]^{\dfrac {1}{n}}}{n}$$ Attempt: Let $$y=\lim_{n \rightarrow \infty} \dfrac {[(n+1)(n+2)\cdots(n+n)]^{\dfrac {1}{n}}}{n}$$ $$\implies \log y = \lim_{n \rightarrow \infty} \dfrac {1} {n} [\log (n+1) +\cdots+log(n+n)-log(n)] $$ How do I move forward? Thank you very much for your help. |
Some of my contents which are coming directly from MySQL database are displayed like ’ , — characters. I guess while inserting the data into the database, I mistakenly used SET NAMES utf-8 instead of SET NAMES utf8. For which the special characters are not converted properly and showing as it is. In order to avoid these I used the follwoing in the page between <head> tag .. <meta http-equiv="Content-Type" content="text/html";charset=UTF-8" /> . But it didn't work. How to convert these into its original characters while showing in the page ? | I'm setting up a new server and want to support UTF-8 fully in my web application. I have tried this in the past on existing servers and always seem to end up having to fall back to ISO-8859-1. Where exactly do I need to set the encoding/charsets? I'm aware that I need to configure Apache, MySQL, and PHP to do this — is there some standard checklist I can follow, or perhaps troubleshoot where the mismatches occur? This is for a new Linux server, running MySQL 5, PHP, 5 and Apache 2. |
This is an exercise from Hungerford chapter 2 section 3. Here $G $ is said to satisfy the ACC and DCC. Then how should I apply the Krull Schmidt theorem to prove the proposition in the title? I tried to show that $G×G $ itself satisfies the ACC and DCC but to no avail. Could anyone help me? | I was thinking about the following problem: Suppose that $G_1 \cong G_2$ are isomorphic groups. Under what conditions on the groups $H_1,H_2$ will we have $$G_1 \times H_1 \cong G_2 \times H_2 ?$$ Obviously, in the finite case we must have $|H_1|=|H_2|$. Also, it is easy to see that $H_1 \cong H_2$ is sufficient. Is it necessary as well? Thank you! |
Is it possible to change Caps Lock to a special character like $ (most use in PHP) ? | How can xkb or some other tool be used to permanently bind Caps Lock to ctrl+b while in terminal? (This is to make Caps Lock the default prefix key for tmux. It could also be mapped to a specific key if that's too difficult, e.g. a function key, which could then be made the tmux prefix instead.) |
I'm sure that the Pokedex says that a Cubone has the skull of it's dead mother, so if the first one appears, does it have a copy of it's skull, or not? | The Pokédex entry for Pokémon Yellow says that wears its mother's skull: Wears the skull of its deceased mother. Its cries echo inside the skull and come out as a sad melody. This might seem like a reference to the Marowak that was in the Frist Generation games, meaning it's an overgeneralization of a specific instance of a single Cubone's tragic story. However, similar Pokédex entries appear in nearly ever game, suggesting that many, if not all, Cubone wear their mothers' skulls. Pokémon Moon's entry goes a step farther by suggesting that dealing with its mother's death is a necessary part of evolution: The skull it wears on its head is that of its dead mother. According to some, it will evolve when it comes to terms with the pain of her death. How is it logistically possible that every Cubone has a dead mother whose skull it wears, and that they must come to terms with her death in order to evolve? Also, wouldn't that mean a female Cubone/Marowak can only have one child since they only have one skull to give? |
What I want to do is Format my SSD disk of my Mac Book Pro (2019), but I want to do it in a VERY safe way. So that there is no trace of the deleted files and nobody can access them anymore. That's why I think the best option is to look for a software that formats the disk doing a lot of reading and writing. I can't find good and reliable software that does that on a Mac. Is there one? | I would like to sell my Macbook Pro, but I want to make sure that there is no way to retrieve the deleted data from my SSD. Is there a way to completely delete all files on a hard drive so that even a forensic expert cannot recover anything? |
Prove the set of limit points in a $T_1$ space is closed. Definitions: Limit Point: $x$ is a limit point of a set if every open set that contains $x$ contains at least one other point of the set that is not $x$. $T_1$-space: All pairs of disjoint points have neighborhoods not containing each others' points. I wrote that all points in the set of all limit points are disjoint from the complement of the set of all limit points, so all the points in the complement of the set of all limit points have neighborhoods that are disjoint from all the neighborhoods of all the points in the set of all limit points, but this was marked incorrect. How should I go about proving this correctly? | Let $X$ be a Hausdorff space and $A\subset X$. Define $A'=\{x\in X\mid x\text{ is a limit point of }A\}$. Prove that $A'$ is closed in $X$. Relevant information: (1.) Every neighborhood of a point $x\in A'$ contains a point $y\in A'$ distinct from $x$ (in fact, in a Hausdorff space, every neighborhood of $x$ contains $\infty$-many points of $A$ distinct from $x$) (2.) In a Hausdorff space, every sequence has a unique limit. On first glance, it should be an easy proof, but I've made little progress. I was planning on showing $\overline{A'}=A'$. Firstly, $A'\subset \overline{A'}$ trivially. To show $\overline{A'}\subset A'$, proceed by contradiction. Assume there exists $x\in\overline{A'}$ such that $x\not\in A'$. This should yield an easy contradiction but I don't see it. In particular, I'm unsure if the fact that $x\in\overline{A'}$ implies that there actually exists a sequence in $A'$ converging to $x$. By (2) we know all sequences have unique limits, but do we know that elements in the closure are limits of sequences? If this is true, it should yield an easy contradiction. Any help? |
We are using Lightning Experience. We have a single user license and it has the administrator profile. We want to send emails through Gmail. We have completed the setup following these instructions from () From Setup, in the Quick Find box, enter Send through External Email Services, and then select Send through External Email Services. Select either Send through Gmail or Send through Office 365. From Setup, enter Deliverability in the Quick Find box, then select Deliverability under Email. Set the access level for sending email to All email. We are still unable to send emails via Gmail. All emails are still going from salesforce. It appears that there is another step involved at a user level () When the user tries to send the next email, an option to select the option should appear. We don't see that. Also, we don't think "Send Email Through Email Relay" is relevant in this case. That's for companies with their own domain/SMTP servers, etc. Appreciate any pointers you can provide. Thanks! | I was wondering what other organizations using gmail have done for email relaying with Salesforce. My organization will not be removing the gmail authentication so I was wondering if there is a work around, or if other organizations are using another service to be able to send emails from Salesforce without the "via" link. I'm looking into AWS Simple email Service (SES) and send grid to send our one-off transactional emails. I would like to hear what others have done to get around this issue. Thanks! |
I don't need to catch the exception, but I do need to Rollback if there is an exception: public async IAsyncEnumerable<Item> Select() { var t = await con.BeginTransactionAsync(token); try { var batchOfItems = new List<Item>(); //Buffer, so the one connection can be used while enumerating items using (var reader = await com.ExecuteReaderAsync(SQL, token)) { while (await reader.ReadAsync(token)) { var M = await Materializer(reader, token); batchOfItems.Add(M); } } foreach (var item in batchOfItems) { yield return item; } await t.CommitAsync(); } catch { await t.RollbackAsync(); } finally { await t.DisposeAsync(); } } (This code is a simplified version of what I am doing, for illustration purposes) This fails with the message: cannot yield a value in the body of a try block with a catch clause This is similar to , but this has novel context: "IAsyncEnumerable" which is relatively new. Postgresql (for which the answer uses an internal property) This question has a better title, explicitly referring to "Transaction" context. Other contexts with the same error message won't have the same answer. This is not the same as . In my case, the context is more specific: I need the catch block to Rollback, not to do anything else. Also, as you can see, I already know the answer and created this as a Q&A combo. As you can see from the answer, that answer isn't relevant to | The following is okay: try { Console.WriteLine("Before"); yield return 1; Console.WriteLine("After"); } finally { Console.WriteLine("Done"); } The finally block runs when the whole thing has finished executing (IEnumerator<T> supports IDisposable to provide a way to ensure this even when the enumeration is abandoned before it finishes). But this is not okay: try { Console.WriteLine("Before"); yield return 1; // error CS1626: Cannot yield a value in the body of a try block with a catch clause Console.WriteLine("After"); } catch (Exception e) { Console.WriteLine(e.Message); } Suppose (for the sake of argument) that an exception is thrown by one or other of the WriteLine calls inside the try block. What's the problem with continuing the execution in catch block? Of course, the yield return part is (currently) unable to throw anything, but why should that stop us from having an enclosing try/catch to deal with exceptions thrown before or after a yield return? Update: There's an - seems that they already have enough problems implementing the try/finally behaviour correctly! EDIT: The MSDN page on this error is: . It doesn't explain why, though. |
French Embassy in San Francisco states the following in the "Help" section: Application by mail is possible for short stay visas only, not for long stays. If you already hold a short stay visa bearing the mention "VIS" on it issued less than 5 years ago or a short stay visa issued by the French Consulate after January 2017, you don’t have to apply in person (even if this visa is expired, or if it is in an old passport). In that case, you may apply by mail. Please mail us your completed application form along with a copy of all the supporting documents as indicated by France Visas. However while applying for French short term visa the "previous Schengen visas" section asked "issued within previous 3 years". So it is 5 or 3? I was issued a Spanish Schengen visa in 2013 so that's within previous 5 years but not within previous 3. I did not know this 5 year thing so I applied for visa interview anyway. But if I need another short term visa soon, will my previous Spanish visa (or French visa if I get it this month) be considered? Also, I do not remember if I was every fingerprinted for Spanish Schengen visa, so I selected "Not fingerprinted" in the application. | I had my French Schengen visa interview 3 days ago (got the stamped visa and passport within two days, super efficient!). However there's no "VIS" written on the visa, even though I gave my fingerprints during the interview in US. I had presumed VIS would be written on the visa since I gave my fingerprints, or is it for something else? I do remember it took a while to take the fingerprints because the machine looked old and was taking a long time to read my fingerprints. The next time I want to apply for a visa, do I need to go for an interview again just because the visa has no VIS on it? |
The usual definition of a finite number $n$ in the ZFC set theory is $n\in\mathbb{N}$, which is equivalent to "$n$ is 0 or a successor ordinal, and so are all its elements". But this is not obviously equivalent to the intuition of a finite number, which would rather be a group of sticks that one can draw on a paper or a wall. And by the compactness theorem, we can consistently add a new constant symbol $c$ to ZFC, together with the axioms $c\in\mathbb{N}$ and $0 < c, 1 < c, 2 < c, ...$ We call numbers such as $c$ non standard. I am particularly interested in proving the termination in finite time of certain algorithms or computer programs. And I am now concerned with the following type of reasoning : assume by contradiction that for all $n\in\mathbb{N}$, the program runs for more than $n$ steps, and derive a contradiction. Conclude that there exists an $n\in\mathbb{N}$ such as the program terminates in less than $n$ steps. What if this number $n$ was non standard ? It would prove nothing regarding the intended meaning of termination of a program. Is there a meta-theoretical property of ZFC, telling that every definable $n\in\mathbb{N}$ is standard ? Or telling that the proved existing $n$ above is standard ? | This is a bit of a philosophical question. According to "Set Theory" by Jech, the set $\omega$ of natural numbers is defined as the least nonzero limit ordinal. After thinking about this definition recently I found no reason why this set should neccessarily be restricted to contain only the numbers obtained by applying the successor operation to zero, what is the intuitive notion of natural number. I did not even find a way to formulate the statement that all elements of $\omega$ are of this form. To be more technical, is it in fact possible to consistently add an element $x$ to the theory together with axioms that assert $x\neq0,x\neq 1,\ldots$ ? |
Is it possible to place a matrix in a Section Heading? This is my current attempt: \section{Analyze the invertible $M= \left[ \begin{array}{rr}2 & 6 \\ 2 & 4 \end{array} \right]$ matrix by doing the following:} I want it to read: Any help is appreciated as I am new. | I was trying to insert matrix into a \subsection{}: \subsection{Suppose $X= \begin{array}{cc} 1 & 2 \\ 3 & 4 \end{array}$} This gives me an error: ! TeX capacity exceeded, sorry [input stack size=5000]. What is wrong here? Thanks! |
I've a question about arcpy List* modules. I have a quite large amount of data on ArcSDE Server. Earlier I made a list of the feature classes, and tables in the mxd-s placed there using da.Walk and ListFeatureClasses/ListTableViews. Now I'd like to list the joined tables too, but I've no further idea how to do it. Actually is it possible to get these relations? | I have some Python code that is launched from within an ArcMap project. Any joins that the user may have created in the project must be removed in order for my code to run. Unfortunately, the code that removes a join… arcpy.RemoveJoin_management("layer1", "layer2")… also breaks some of the layer properties that are critical to my application (highlighted fields, read-only fields, etc). If joins are removed by right-clicking the layer in ArcMap and choosing “Remove Joins” the layer properties are left intact. If I can detect that a join exists from within my code, I will simply exit the code and display a message that the user must manually remove their joins before attempting to run the code. So… Can a Join be detected programmatically? |
I am a Ph.D student from mathematics background and about to submit my thesis in a month or two. I am thinking to apply for postdoc position. Shall I send my normal cv or the one bearing my photo? Thanks for the help and suggestions. | I think I have only seen one CV where a photograph of the CV owner was included. I personally wouldn't want to put my photograph in my CV, but I was wondering, in what situations would including a photo if oneself within the CV be appropriate? |
So apparently when using javascript to make a copy of an array copies a reference and so I get pass by reference issues. Good to know. So how do I copy an array of objects (a class effectively) without passing by reference. I tried using slice but it didnt work. Thanks. | What is the most efficient way to clone a JavaScript object? I've seen obj = eval(uneval(o)); being used, but . I've done things like obj = JSON.parse(JSON.stringify(o)); but question the efficiency. I've also seen recursive copying functions with various flaws. I'm surprised no canonical solution exists. |
I'm not sure if it is due to the latest Windows 10 update or something else. But recently, OpenVPN won't start up automatically anymore. Even though it is placed in the user autostart folder for the start menu. Any advice on how to trouble shoot this? | I've been running into a problem where some of the applications from the startup menu don't actually start upon login. After looking at the list of the applications I've noticed that actually only the exe files that I've set in properties to "Run as administrator" (in compatibility tab) don't run (and also a .cmd file). How do I run those apps during startup? |
Let's say we have a white noise process $x(t)$ such that: $E(X(t)X(t+\tau))=N\delta(\tau)$ $E(X(t))=0$ In particular, with $\tau=0$, $E(X(t)X(t))=E(X^2(t))$ is infinite. Now, I want $X(t)$ at each time $t$ to have a normal distribution of 0 mean and $\sigma^2$ variance. That is: $E(X^2(t))=\sigma^2$ This is not consistent. I guess the expectations mean something different in both cases, but I don't find an explanation. This prevents me from moving ahead in a study of the mean, variance and autocorrelation of a process $y(t)$ defined as $y(t)=1$ if $a<x(t)<b$ and 0 otherwise. | What is meant by a continuous-time white noise process? In a discussion following a a few months ago, I stated that as an engineer, I am used to thinking of a continuous-time wide-sense-stationary white noise process $\{X(t) \colon -\infty < t < \infty\}$ as a zero-mean process having autocorrelation function $R_X(\tau) = E[X(t)X(t+\tau)] = \sigma^2\delta(\tau)$ where $\delta(\tau)$ is the Dirac delta or impulse, and power spectral density $S_X(f) = \sigma^2, -\infty < f < \infty$. At that time, several people with very high reputation on Math.SE assured me that this was an unduly restrictive notion, and that no difficulties arise if one takes the autocorrelation function to be $$E[X(t)X(t+\tau)] = \begin{cases}\sigma^2, & \tau = 0,\\ 0, & \tau \neq 0. \end{cases}$$ What engineers like to call a white noise process is a hypothetical beast that is never observed directly in any physical system, but which can be used to account for the fact that the output of a linear time-invariant system whose input is thermal noise is well-modeled by a wide-sense-stationary Gaussian process whose power spectral density is proportional to $|H(f)|^2$ where $H(f)$ is the transfer function of the linear system. Standard second-order random process theory says that the input and output power spectral densities $S_X(f)$ nd $S_Y(f)$ are related as $$S_Y(f) = S_X(f)|H(f)|^2.$$ Thus, pretending that thermal noise is a white Gaussian noise process in the engineering sense and pretending that the second-order theory extends to white noise processes (even though their variance is not finite) allows us to get to the result that the output power spectral density is proportional to $|H(f)|^2$. My query about the definition of a white noise process is occasioned by a regarding the variance of a random variable $Y$ defined as $$Y = \int_0^T h(t)X(t)\ \mathrm dt$$ where $\{X(t)\}$ is a white Gaussian noise process. The leads to $$\operatorname{var}(Y) = \sigma^2 \int_0^T |h(t)|^2\ \mathrm dt$$ (as I pointed out in a comment on the answer) if the autocorrelation function is taken to be $R_X(\tau) = \sigma^2\delta(\tau)$ (the engineering definition). However, the OP on that question specified $R_X(0) = \sigma^2$, not $\sigma^2\delta(\tau)$, that is, the definition accepted by mathematicians. For this autocorrelation function, the variance is $$\int_0^T \int_0^T E[X(t)X(s)]h(t)h(s)\mathrm dt\mathrm ds = 0$$ since the integrand is nonzero only on a set of measure $0$. So, what is the variance of the random variable $Y$? and what do readers of Math.SE understand by the phrase white noise process? Perhaps this question should be converted to a Community wiki? |
I’m currently encountering some problems analyzing a dataset with neural network. The problem is that I have an unbalanced binary class training set (10:1). Training accuracy for both classes are 100%. When predicting I get accuracy of 99% for the majority class in the validation set, and accuracy of 0.2% for the minority class. So I was wondering if over-sampling would help to improve the accuracy for the minority class. | This is a question in general, not specific to any method or data set. How do we deal with a class imbalance problem in Supervised Machine learning where the number of 0 is around 90% and number of 1 is around 10% in your dataset.How do we optimally train the classifier. One of the ways which I follow is sampling to make the dataset balanced and then train the classifier and repeat this for multiple samples. I feel this is random, Is there any framework to approach these kind of problems. |
I have a SSD for boot up ands its fast. I do not want the computer waiting for me to load all of my programs and services. I am the only user on my account. Is there a way to require the password after login. Alternatively if there is no proper way of doing it, I have found that: Lock Workstation: Rundll32.exe User32.dll,LockWorkStation could maybe also be used. Is there a proper way of doing it in the windows. If not how can I have that command up there set to a startup script. If I were to go into Lock mode after login would in windows continue to run the start up procedures | I want to configure Windows 7 to login automatically after the computer is switched on. That's not because I'm lazy and don't like typing passwords. That's because I want programs that are configured to run on startup run automatically. But I don't want everyone to see my desktop, so I want my computer to remain locked. When I'm ready to work, I just type my password and don't have to wait until all startup programs run. |
I am having two client-side controller methods, How to pass the response of the first wire method as a parameter to the second wire method. The second wire method is dependent on the first methods returned data. @wire(method2, { oinputmap: "$inputMap", intname: "$interName" }) wiredresponse({ error, data }) { //({ oinputmap: this.inputMap,intname: this.interName }) if (data) { var responseObj = JSON.parse(data); console.log("result activate card" + responseObj); if (responseObj.Result.Code === 0) { this.description = "Card Activated." + responseObj.Result.Description; //TODO: Update XPAC in card } else { this.description = responseObj.Result.Description; } console.log("result" + responseObj.Result.Description); } else if (error) { console.log("buildandcallinterface:Exception in fetching card number"); } } | According to the documentation in order to retrieve a list of picklist values for an object we need to pass in a Record Type Id which can be retrieved using the getObjectInfo method. The issue is that these are both wire functions and I cannot figure out how to chain these methods. If I try code like the following: getObjectInfo({ objectApiName: ACCOUNT_OBJECT }) .then(result => { return getPicklistValues({recordTypeId: result.defaultRecordTypeId, fieldApiName: TYPE_FIELD}); }) .then(result => { this.picklistValues = result.data }) .catch(error => { this.error = error; }); I get an error render threw an error in 'c:getpicklistexample' [Imperative use is not supported. Use @wire(getObjectInfo).] If I try something like @track rtId; @wire(getObjectInfo, { objectApiName: ACCOUNT_OBJECT }) handleResult({error, data}) { if(data) { this.rtId = data.defaultRecordTypeId; } } @wire(getPicklistValues, {recordTypeId: this.rtId,fieldApiName: TYPE_FIELD}) picklistValues; Then it throws an internal server error. Anybody have an idea as to how I could retrieve the record type Id and then call to get the pick list values like the documentation suggests? FYI my imports are: import { LightningElement, wire, track } from 'lwc'; import { getPicklistValues, getObjectInfo } from 'lightning/uiObjectInfoApi'; import TYPE_FIELD from '@salesforce/schema/Account.Type'; import ACCOUNT_OBJECT from '@salesforce/schema/Account'; |
So that's bicycle, skateboard, scooter etc. Problem is that these also have motor powered versions, but if you just say vehicle, people will think that you mean cars or something. Also, you can't search for those powered versions collectively because what would you put in the search bar, "motor powered, human powered vehicles"? If you just use "powered vehicles" all results are cars. | I am putting together information regarding common suburban vehicles. I have a list of vehicle categories with several vehicle examples in each category. For example: SUV Ford Explorer Jeep Wrangler Sports Car Mazda MX-5 Toyota 86 Super Car Chevrolet Corvette Nissan GTR Truck RAM 2500 Chevrolet Colorado I would also like to add a combined category for non-powered vehicles such as skateboards, bicycles, scooters etc commonly used by children. I'm not sure what exactly to call this category though. I don't really like "non-powered vehicles" because it tends to have a negative connotation which the kids using them won't appreciate. I'm open to slang if it is relevant, but it does not necessarily have to be slang. Any suggestions? |
I'd like the gradient to have more depth like the red graphic has | I have seen such an effect being used in many places however I haven't figured out how to replicate it via Photoshop. I have tried desaturating the image, placing it under a layer of solid colour and then lowering the opacity of the colour. I have also tried a couple of blend modes, to no avail. The effect is nowhere near the same. Can someone please tell me the effect used on these images? |
Let $f\in C^1[a,b]$, $f(a)=0$ and suppose that $\lambda\in\mathbb R$, $\lambda >0$, is such that $$|f'(x)|\leq \lambda |f(x)|$$for all $x\in [a,b]$. Is it true that $f(x)=0$ for all $x\in [a,b]$? Solution: Say there exits an interval $[c,d]$ where funtion $f(x)$ is non zero so $|f(x)|$ is differentiable in $[c,d]$ with $f(c)=0$. Now consider the function $g(x)=e^{-\lambda x}|f(x)|$ and see that $g'(x)\leq 0$. So $g $ is decreasing. So, $x\geq a \implies g (x)\leq g(a)=0$. Hence, $|f (x)|\leq 0\implies f (x)=0$ Is this solution correct? basically i am asking is the differentiablity of $|f(x)|$ makes sense | $f$ is differentiable on $[a,b]$, $f'(x) \leq A|f(x)|$ where $A$ is a non-negative constant. If $f(a)=0$ show $f(x)=0, \forall x\in [a,b]$ I imagine the proof uses the Mean Value Theorem but I have not been able to get it to work. I know $|f(x)|=|f'(c)|(x-a)$ where $c \in [a,x]$, so $|f(x)| \leq A\ |f(c)|(x-a)$ where $c\leq x$ And I guess I could sort of iterate this to keep getting a smaller $c$ but I don't see why it must go all the way to zero. |
I've been tasked with converting jQuery to vanilla JS. I've run into trouble figuring out the proper way to convert the selector argument in an .on() event handler. .on( events [, selector ] [, data ], handler ) I'm at a lost as to how the selector argument in .on() actually works and what I need to do to properly replicate it. Here is the jQuery that I am trying to convert: // jQuery I'm converting from $('body').on('touchstart', '#chatListDisplay .chatEl', () => { ... }); I've tried just including the selector argument the element that is used in the original jQuery by passing it into querySelectorAll(). // My attempt at vanilla var chatEls = document.querySelectorAll('body #chatListDisplay .chatEl'); chatEls.forEach((el) => { el.addEventListener('touchstart', () => { ... }); }); The event handler never fires in this case, so I took some time to think of what my attempt actually represents in jQuery. It probably matches this: $('body #chatListDisplay .chatEl').on('touchstart', () => { ... }); As expected, changing the original jQuery to the above also results in the event handler not firing. | I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off. This happens on page ready and works just fine. The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound. I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option. |
A similar question had already been asked, but the solution involves steps I am unfamiliar with. in class, we have only been exposed to intro and elim rules, as well as contradiction rules. Here is the original question: I am not familiar with "DS" as a method | It's all in the question really. I am working on a proof in Fitch for a class, but I am very much stuck. I am proving the tautology that "(P → Q) ↔ (¬P ∨ Q)", and I have already finished half of it, but now I must prove that "(¬P ∨ Q)" implies "(P → Q)". I can't seem to get anywhere. I try to set up a proof by cases where I assume in different subproofs "¬P" and (in the other) "Q", but then I must prove "P → Q" from those. It seems even more difficult. Any help would be appreciated. |
Which is correct: "we agree to notify you if any of our intentions has changed" or "we agree to notify you if any of our intentions have changed"? | I always thought with "any" I should use the plural, but on the internet I can find both: It can be found in any book. It can be found in any books Do you have any books? It can be said in any language. This can be understood by anyone. It has been used in any form. So, what's correct? Is there any rule? |
I have a fairly simple question for you, regarding a getText().toString() method I'm using in an if statement. Essentially, I'm asking the user a question. If they input the correct answer in the appropriate EditText, they move on to the next question. If not, they lose life. If their life is reduced to 0, they are sent back to the beginning of the game. If not, they must repeat the question. The problem I'm having while testing this is that after entering the correct answer, in this case "Atlantic", the method is executing as though the answer is wrong. Can anyone help with this? PS I am aware that the Else If is redundant, it's just there for clarification purposes. The code: answerButton.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { if (answerText.getText().toString() == "Atlantic") { KrakonQ2(); } else if (answerText.getText().toString() != "Atlantic") { thePlayer.setPlayerHP(thePlayer.getPlayerHP() - 20); if (thePlayer.getPlayerHP() <= 0) { thePlayer.setPlayerPos(0); setupControls(); RoomText.setText(thedungeon[thePlayer.getPlayerPos()].getName()); setupDirectionButtons(); thePlayer.setPlayerHP(100); } else { KrakonQ1(); } } } }); | I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug. Is == bad? When should it and should it not be used? What's the difference? |
I have plenty of files in a folder with extension of .dep, I want to hide these files. But I don't want to change their names such as adding a dot ahead of them. What would be the best way to do this? Thanks! | I have set of temp files created in my folder with .bak extensions. How can I make them hide by default in Ubuntu? I tried adding a .hidden file with *.bak as entry in the file, but that is not working. Any help is very appreciated... |
The question. Can every $n\in \mathbb N$ can be written: $$n=a^2\pm b^2\pm c^2$$ where $\pm$ are signs of your choice? We know with that every integer can be written as the sum of four squares. Plus, with have stated that an integer can not be written as the sum of three squares if, and only if, it is of the form: $$4^k(8n+7).$$ So we just have to prove (or disprove) it for every number of this form. I have checked it until $55$, and it seems to work so far. So the number we have to check are . For instance: $$31=6^2-2^2-1^2$$ and $$39=6^2+2^2-1^2.$$ The issue here is that $a$, $b$ and $c$ can be arbitrarily large. For instance: $$183=14542^2-14541^2-170^2.$$ So I don't really know how to prove or disprove this result, and I think it could go either way. | Let $Q$ be the ternary quadratic form $Q(x,y,z)=x^2+y^2-z^2$. Since $Q(0,p+1,p)=2p+1$ and $Q(1,p+1,p)=2p+3$, we see that for every integer $k$, the equation $E_k:Q(x,y,z)=k$ always has a solution. Is it known for which integers $k$ there are infinitely many solutions to $E_k$ ? |
Are threads more efficient or creating a sub process more efficient in c where execution of parts of code is independent of other and which is efficient while writing code for a server to handle requests i am trying to figure out weather sub process is more useful or threads, when we have to execute parts of single program in parallel on a server based on the requests from clients. i have read both disadvantages and advantages of threads and sub process.When i have parts of code that have to be executed in parallel and each part is independent of other which one is preferred a sub process or thread and why i have found some delay in execution while using fork() system call but thread is fine and when one thread caused error will it effect other thread | What is the technical difference between a process and a thread? I get the feeling a word like 'process' is overused and there are also hardware and software threads. How about light-weight processes in languages like ? Is there a definitive reason to use one term over the other? |
Let G be a group. Prove that the function: $G→G, x→x^2$ is a group homomorphism if and only if G is an abelian group. Is this the same as if $f:G→G$ is defined by $f(x) = x^2$ ? | The function $f: G→G$ defined by $f(x) =x^2$ is a homomorphism if and only if $G$ is abelian. Can anyone give me any tips how to work on this question? |
My intuition is NULL will take up less space than {} when used as the default value of an ARRAY[] column in PostgreSQL. Am I correct? | I have 400 million rows in a Postgres db, and the table has 18 columns: id serial NOT NULL, a integer, b integer, c integer, d smallint, e timestamp without time zone, f smallint, g timestamp without time zone, h integer, i timestamp without time zone, j integer, k character varying(32), l integer, m smallint, n smallint, o character varying(36), p character varying(100), q character varying(100) Columns e, k, and n are all NULL, they do not store any values at all and are completely useless at this point. They were part of the original design, but never removed. Edit - most of the other columns are non-NULL. Questions: How can I calculate the impact this has on storage? Is it equal to size of column * # of rows ? Will dropping these empty columns noticeably improve performance for this table? Would the page cache be able to fit more rows? |
I have 3 domains: domain.com, domain.org, and domain.net I have an SSL cert for .org, but not .com and .net. I would rather not have to purchase SSL certs for all 3 TLDs. How do I redirect the .com and .net domains to .org ? Normal HTTP apache redirection methods don't seem to be working. Thanks in advance. | We're using setup with an nginx on one machine and (currently) one application server on apache in the back. For multiple domains we got ssl certs, but only for the domain itself. So without subdomain www. Everything works as expected, we do not use the anywhere. But we have customers who are typing this in by hand, resulting in a warning in the browser on the clientside. ..and a new seo guy insisting on working www subdomain WITH ssl. What am i looking for: A creative solution which does not require new certificates for 20+ domains. I already thought about getting certificates from let's encrypt for our www subdomain, then 301 to domain.tld.. but it's still in beta. Any ideas ? |
Question, How can I turn On an LED powered by 2 AA Batteries Switched on from a low voltage .15v from a small Genorator? When the wind blows The small Generator has a propeller and I would like to send a signal to turn on the The LED that is powered by 2AA batteries. The generator Is not powerful enough to light the LED on it's own for this application. It is a model of a wind turbine for demonstration purpous so it will not produce enough power on its own to light up anything. Thank you for your help | How to activate a pn2222 transistor with very low voltage 0.15 volts or 150 mV from a small dc can motor Generator. I would like the Transistor to turn on as soon as the generator starts producing current. the problem I had is the Power source is running back through the Transistor and spinning the Motor/Generator. I want the Generator to give power to the base of the Transistor to activate some LEDs. This is a small 6 volt can motor as a wind generator. I also tried a 3A Solid state Relay but it needs conrtol voltage at least 3 v. Would it be reasonable to try a Ge transistor instead of the Si one . Thanks |
I know how to set a Minecraft server and I already know about plugins, but how do I install mods on it? For example; Deathchest, Pokemobs, Mo' Creatures, Recipe Book, TooManyItems, and all the things necessary to make them run. I've looked everywhere. wont give out how they set their servers up with mods but they have and and some others. I only found a custom thing needed to play on their server. Is this related to the version I'm running? If i have to downgrade my Minecraft from 1.2.5 this isn't a problem. | I was wondering how to add plugins to my Minecraft server. I am using Bukkit, and the things I would like to be able to do is spawn stuff, teleport to other players, set home locations, have an in-game currency/shop and be able to teleport to homes. |
I am going to buy a Macbook Pro 2018 15". I am just wondering, if it is possible to connect two monitors via one docking station. If there is any docking station, which it supports 2 monitor connections and extending the view (not mirroring). I don't want to use 2 hdmi adapters because I will need to buy the docking station anyway to have usb and ethernet connections. | How do I connect dual screen setup on a Mac Mini? Mac Mini: Late (2012) Apple Cinema Display 27" Apple ThunderBolt Display 27" ThunderBolt Port: Apple ThunderBolt Display 27" Tried two different Kanex XD units and did not work. Kanex XD: Mini display port female to HDMI female converter to HDMI cable to HDMI Port on Mac mini. Does anyone have a link to a converter that work or an option to hook up? |
I am writing a mathematical paper, and in it I need to include certain images relevant to the topic. However, when I try to do so, I receive an error code, and nothing I have found on the subject is giving me any insight on how to relieve this error. I have the following; \usepackage{graphicx} \graphicspath{ {C:/Texpics} } \begin{document} \includegraphics{img.png} And I receive; ! LaTeX Error: File `img.png' not found. Any advice would be appreciated. Working in both TeXworks and Texmaker gives the same result. | I am trying to include a graph in a tex document. I do realize that there have already been several questions asked about this topic, but I think by now I have tried all suggested solutions but none seem to work. This is the minimal example: \documentclass[12pt]{report} \usepackage{graphicx} \graphicspath{{C:/Users/felix/Desktop/Bachelorarbeit/TeX/BA_text2/images}} \usepackage[a4paper]{geometry} \begin{document} \begin{figure} \includegraphics[scale=1]{gap_v3_v4_AT.png} \end{figure} \end{document} Information about my setup: I am using Texmaker and MiKTeX 2.9. Things I have tried: Absolute and relative paths, not initialising a figure environment, including the directory where the graph is in the MiKTeX Options-> root directory (was suggested in one of the answers to a similar question) There is definetly a .png file with the same exact name in the folder set by \graphicspath. I would be really grateful for any ideas! |
How do we execute a command such as it executes everytime one logs out or shutdowns or restarts the machine ? To be more specific, I want the autotrash to be executed at logout, or shutdown or restart. | I'd like to run a .sh file using bash on logout and shutdown of Ubuntu. I have searched up and down the web and have found only fixes for KDE and GNOME. The script is simple, I just need to know if I can add the line of code to the "logoff/shutdown" file or if I need to reference it in another script. |
Bezier curves 1, 2 and 3 are all using the curve "Bev ob" as a bevel object. Why are they different sizes? I saw and checked that the radius is set the same for all vertices on all three objects. | The bevel depth (the radius of the tube) is set to 9cm but it actually isn't when compared to the background grid. This is is confirmed by importing it into sketchup and scaling it to the proper units it turns out the radius is only around 2.286cm. This problem only shows up on certain projects. What's wrong and how do I fix it? (sorry that I can't upload the file, it's a long story) |
I am using the book style \documentclass[11pt,openright]{book} but the title, index starting and all the capters have larger margin in the right proper of documents opening on the left. I tried to change the option to \documentclass[11pt,openleft]{book} but there is no change on the page positioning. Another option is to change the margins definition using this: \usepackage[a4paper,inner=3.5cm,outer=2.5cm]{geometry} but it seems like an improper work-around to me. I'm sure there is a way to properly set it from the book class already. Is there any other parameter to tune? or sould I apply the geometry solution and forget aobut it? | Shouldn't the twoside option produce a wider margin at the binding/spine edge, rather than the other way around? I'm using \documentclass[twoside]{report}. |
This question is pulled from a number theory practice set that did not provide an answer key. Link: My reasoning is to prove that $n^7$ - n is divisible by 2,3, and 7 because they are the prime factors of 42. I've proven divisibility by 2, but I cannot prove divisibility by 3 or 7. Please let me know if this is the right path, and any ideas are welcomed proving divisibility by 3 or 7. | I can see that this works for any integer $n$, but I can't figure out why this works, or why the number $42$ has this property. |
I'm completely new at blender and yesterday I followed a tutorial and everything turned out fine, not a single problem. So I wanted to try and make something myself, now the only problem is, when I try to render it, I don't see the object. Here is the .blend file: Please keep in mind that I'm completely new. IMG1: This is what it looks like when I choose the "Only render" option in "edit mode" IMG2: This is what it looks like when I choose the "Only render" option in "object mode" IMG3:And this is what I see when I render it.. | I have this stick figure kind of guy doing a dance. He is clearly there in solid mode and texture mode: But when I go into render mode or just try to render an image, it's gone: I can't for the life of me figure out what inconsequential silly mistake I am making. I probably just need another pair of eyes to look at it. Here is a link to the .blend file. Don't judge me, I'm trying to teach myself rigging and animation: |
Question: Which partitions $P$ of $n$ give the row and column sums of some $|P| \times |P|$ $(0,1)$-matrix? Someone comes along and gives us the partition $P=\{2,2,3,3,4\}$ of $14$. How can we determine if there's a $5 \times 5$ matrix whose rows and column sums both give rise to that partition? In the example, it's realized by this matrix: $$\begin{bmatrix} 1 & 0 & 1 & 1 & 0 \\ 0 & 1 & 1 & 0 & 0 \\ 0 & 1 & 0 & 1 & 1 \\ 1 & 0 & 1 & 1 & 1 \\ 1 & 0 & 0 & 1 & 0 \\ \end{bmatrix}$$ but I cheated: I generated the example partition from the matrix. Observations: The obvious necessary condition is that $\max P \leq |P|$. This is equivalent to asking when is $P$ the out-degree sequence of a directed graph where any vertex may have one loop. (So the or could be applied in some cases, replacing each undirected edge with a bidirected edge; in fact, they would work in my above example.) If we just brute force started filling in $1$'s, we can get stuck. Here I proceed row-by-row, placing a $1$ wherever possible: $$ \begin{array}{c|ccccc} & 4 & 3 & 3 & 2 & 2 \\ \hline 4 & 1 & 1 & 1 & 1 & 0 \\ 3 & 1 & 1 & 1 & 0 & 0 \\ 3 & 1 & 1 & 1 & 0 & 0 \\ 2 & 1 & 0 & 0 & 1 & 0 \\ 2 & 0 & 0 & 0 & 0 & ??? \\ \end{array} $$ Motivation: This is a first step in an attempt at answering my Mathoverflow question: . An answer to this question might help reduce the search space. | We are given ($a_1,a_2,....,a_m$) and ($b_1, b_2,....,b_n$) sequences with non-negative integers. Decide whether it's possible and if it is construct a matrix $\Re^{m x n}$ of ones("1") and zeros("0") where the number of ones("1") in row $i$ is $\forall i $ : $a_i$ and in column $j$ is $\forall j$ : $b_j$ Any hint is greatly appreciated. |
The micro-USB port of my Xperia Arc with ICS it's broken. How can I enter to ADB by wireless, without connecting the cable? I am not root, and I need to enter to ADB to root my phone. I can connect to my phone from my PC by SSH. Or there's a another way to root it? | Is there a way to use adb directly via bluetooth instead of always via usb? -- Thanks for the adb wireless solutions below, but I am looking for something that works well on hotel or public wifi. Bluetooth short-range might be the only way to go about it. |
Command for rename file as IMG0001 to 4R0001 in folder for f in *;do mv "$f" `echo "$f" | sed 's/IMG/4R/g' `; done AND I just want rename selected folder /tmp/2014/1201 (rename files) /tmp/2014/1202 ....... /tmp/2014/1220 /tmp/2014/1224 (rename files) /tmp/2014/1227 ....... find not good for selected folder awk for selected folder by renamelist.txt but miss match with for loop $value Thanks | I have the below list of files aro_tty-mIF-45875564pmo_opt aro_tty-mIF-45875664pmo_opt aro_tty-mIF-45875964pmo_opt aro_tty-mIF-45875514pmo_opt aro_tty-mIF-45875524pmo_opt that I need to rename to aro_tty-mImpFRA-45875564pmo_opt aro_tty-mImpFRA-45875664pmo_opt aro_tty-mImpFRA-45875964pmo_opt aro_tty-mImpFRA-45875514pmo_opt aro_tty-mImpFRA-45875524pmo_opt |
I know that decision trees make the split based on some metric such as entropy, information gain, gini index etc. But for continous variables how does it figure the value at which to make a split. For example, my split is on age. How does it find out a specific age and decides values greater than this go to right, and vice versa.? Is it the mean value? | Can anyone please explain how splitting is performed in regression trees when we only have continuous features. I have referred to different papers, but all I could find is formulas or theorems. Can someone please explain, with an example, how we can build a regression tree from scratch? That would be a great help. |
Given a simple Graph $G=(V,E)$ ($V$ vertices, $E$ edges) I have to show that there exists a distribution $V= V_1 \cup V_2$ of the vertices such that all vertices in the induced subgraphs $G[V_1]$ and $G[V_2]$ have even degree. I honestly have no idea how to solve this question. I tried several things (which I will list below) but all attempts have failed. induction: Induction on the number of vertices has proven to be extremely ugly for this question, so I dropped the idea really quick. color all circles with odd elements first. use that in $G$ there is an even amount of vertices with odd degree. I do not want a complete answer to this question (at least not for the moment). Does anyone have an idea/tip for this question which doesn't give away too much? I hope you can help me slinshady | I've got an example for this question, but there are many different possibilites and I don't know how to show this for all graphs. Has got anyone any advice how to begin ? Let $G=(V,E)$ be an undirect graph. Then there is a partition $V = V_1 \cup V_2$ of a vertices set, so that all vertices in $G[V_1]$ and $G[V_2]$ have got an even degree. I draw it on paper, but how mentioned it, it's not proven for all and I don't know how. Thank you for any advice. |
I am working on an application which deals with all kinds of USB storage devices(such as taking backup, updating DataLogFile etc) My problem is : I want to write a shell script which is stored in this USB drive(As usb is at center of my project so USB is going to be same but PC's will change) AND this script should be executed as soon as the USB drive is connected to my Linux system.I will not need any kind of "root" or "sudo" permissions for other tasks which I am going to do in this shell script. | What can I do to run automatically a script after I mount/plugin or unmount/unplug a USB device? |
I am only 15 years old,and my primary school education hasn't been that good,also I forgot a lot of things. I would like to start again,and I am asking for your advice. What are some of the good websites/books/methods that can help me? | I want to study biology. I have zero previous knowledge of biology but I know Physics, Chemistry and Maths. From which book should I start? I have heard about Campbell Biology, but it is very costly in India(more than my 1 month's earning). So please suggest books that: Are cheap OR could be found on internet Require no previous knowledge of biology Contain no technical mistakes Adequately explain the topics which they deal with and also mention some history of the topics Edit I am not looking for online videos. I want books; my internet is slow and there are some other problems. You can also tell costly books--Perhaps I could find them in the library or could print it somehow. If Campbell Biology book is available online then please give me the download link. |
Many years ago I saw a Merlin's movie where he used a proverb something like this: Is not the sword who makes the knight!!! ( this is not the correct sentence, but similar). Could someone tell the me movie where he says this? Or perhaps point me some other "reference" (movie/book/etc..) where the similar meaning is used? UPDATE #1 I don't think the specific movie I remember is the . The few bits and pieces I still remember tell me that this may be a "kids/teenager" movie, and perhaps with a "recent years story line" with some kind "Merlin" or the "kid" that travels time. I am really not sure. I think I saw this movie more than 15 years ago (the movie may be older). | In this movie, a boy or a teen somehow ends up in the Arthurian period. He wears glasses and has a knack with inventions and gadgets. He almost gets executed by King Arthur, but he performs a magic to block the sun and gets out, which even the fireball-hurling Merlin finds amazing. He also performs other magic such as lightning (electrical) lance in a jousting arena. I remember other details like he worshiped Elvis Presley as the king and the source of his power, and Merlin figures out he's from the future and brings back some music from the future to party with Knights of the Round Table. I tried to find this movie on my own several times, but it is just too difficult. looked so close, but the synopsis looks different from how I remember, and I remember the kid wore glasses all the time. |
Context (skippable) I was asked (by a friend who is preparing for an exam) whether there was a special trick to compute the determinant of the following matrix. I didn't see anything beyond using the standard computations (like using "Gauss" to compute the value). Then I asked another math student who, while quite bright, is a bit rusty in linear algebra and using sagemath we empirically found the below formula. Of course we were both confused as to a) whether it actually always holds and b) why it holds. Actual question Let $n\in\mathbb N$ be a positive integer. Let $I_n\in\mathbb R^{n\times n}$ be the identity matrix and let $1_n\in\mathbb R^{n\times n}$ be the all-one matrix, that is, the matrix for which every entry is $1$. Now I am confused as to why the following (empirically found) statement holds (or does not): $$\forall n\in\mathbb N:\det(1_n-I_n)=(-1)^{n-1}(n-1)$$ For illustration purposes, here is the matrix for $n=4$ (with the determinant being $-3$): \begin{pmatrix} 0&1&1&1\\ 1&0&1&1\\ 1&1&0&1\\ 1&1&1&0 \end{pmatrix} | How do I calculate the determinant of the following $n\times n$ matrices $$\begin {bmatrix} 0 & 1 & \ldots & 1 \\ 1 & 0 & \ldots & 1 \\ \vdots & \vdots & \ddots & \vdots \\ 1 & 1 & ... & 0 \end {bmatrix}$$ and the same matrix but one of columns replaced only with $1$s? In the above matrix all off-diagonal elements are $1$ and diagonal elements are $0$. |
Let $Tf(x)=\int_{[0,x]}fdm$ for $0 \leq x \leq 1$. Prove that $C_0((0,1])=\{f \in C[0,1] : f(0)=0\}$ is a closed subspace of $C[0,1]$ I need a bit of help with this one. I was thinking of proving that the complement is open, or maybe showing that given any convergent sequence in $C_0((0,1])$ its limit has to be in $C_0((0,1])$.... Could use some help though!! THanks! | Prove that the set $$ W= \{f \in C([0, 1]):f(0)=0\}$$ is a closed linear subspace of $C([0,1]).$ Here $C([0, 1])$ is the space of continuous functions equipped with the uniform norm $||f||_\infty = \sup_{x\in[0,1]}|f(x)|$. I need some help in how to proceed with this problem. First, I want to prove that $W$ is, indeed, a subset of $C([0,1])$. For this, we have that for any two functions $f,g\in W$, $f+g\in W$, since $f(0) + g(0) = 0$. Then, also for any $\lambda \in \mathbb{R}$, we have that $\lambda f \in W$, since $\lambda f(0) = 0$. Finally, we also have $0 \in W$. So $W$ is a linear subspace of $C([0, 1])$. My problem is how to prove that $W$ is closed. Based on the definition of a closed set, I wanted to show that a sequence of continuous functions $f_n$ converges uniformly to $f$ and that this $f$ is also in $W$. I started with something like this: Let $f_n$ be a sequence of continuous functions such that $f_n(0) = 0$ for any $n\in \mathbb{N}$. We need to prove that $f_n \to f$, uniformly. i.e $$ \|f_n - f\|_\infty = \sup_{x\in[0,1]} |f_n(x) - f(x)|\to 0$$ as $n\to \infty$. How can I proceed? |
EDIT:: I saw the question mentioned in which the moderator considered mine duplicate. However, I couldn't see how mine is duplicate. My main problem is to write the text in the intersection of CAT B and CAT C. I am trying to create the following Venn diagram. Following is my code and output: \documentclass[border=10pt]{standalone} \usepackage{tikz} \begin{document} \begin{tikzpicture} \begin{scope}[blend group = soft light] \fill[red!30!white] ( 90:1.2) circle (2); \fill[green!30!white] (210:1.2) circle (2); \fill[blue!30!white] (330:1.2) circle (2); \end{scope} \node at ( 90:2) {CAT A}; \node at ( 210:2) {CAT B}; \node at ( 330:2) {CAT C}; \node [font=\small] {text1, text2, text3, text4}; \end{tikzpicture} \end{document} | What I am up to is to write some exercises dealing with logical formulas for my students, like: And the students should draw these formulas on . At the end of the lesson, I really would like to print the correct answer for them. I found a great resource on a forum thread at , which helped me a lot to make up some Venn diagrams with tikz, but have some problems with visualizing complements, like ~A. A simple, modified version of the TeX file found on the forum linked above, can be seen below, which produces the following expression: \documentclass{letter} \usepackage{tikz} \def\firstcircle{(90:1.75cm) circle (2.5cm)} \def\secondcircle{(210:1.75cm) circle (2.5cm)} \def\thirdcircle{(330:1.75cm) circle (2.5cm)} \begin{document} \begin{tikzpicture} \begin{scope} \clip \secondcircle; \fill[cyan] \thirdcircle; \end{scope} \begin{scope} \clip \firstcircle; \fill[cyan] \thirdcircle; \end{scope} \draw \firstcircle node[text=black,above] {$A$}; \draw \secondcircle node [text=black,below left] {$B$}; \draw \thirdcircle node [text=black,below right] {$C$}; \end{tikzpicture} \end{document} Which looks like: Could anyone please help me out plotting/defining some expressions dealing with complements? A nice example could be: That should look like: (image from ) I do not insist on the red color :) I would like to use the simplest possible solution, as I would like to mass generate the exercises with the help of . So any suggestion dealing with gnuplot, R or any other opensource packages is welcome. Thank you! UPDATE (25/01/2011): added details based on answers. Thank you @Leo Liu, you helped me a lot! I modified a bit the code you suggested to be able to color the area outside of the two circles also (in the H universe), but have no idea how to set a background to that polygon also. The code: \begin{tikzpicture}[fill=gray] % left hand \scope \clip (-2,-2) rectangle (2,2) (1,0) circle (1); \fill (0,0) circle (1); \endscope % right hand \scope \clip (-2,-2) rectangle (2,2) (0,0) circle (1); \fill (1,0) circle (1); \endscope % outline \draw (0,0) circle (1) (0,1) node [text=black,above] {$A$} (1,0) circle (1) (1,1) node [text=black,above] {$B$} (-2,-2) rectangle (3,2) node [text=black,above] {$H$}; \end{tikzpicture} And the image generated: I will also look for even odd rule in the near future which does not make sense for me at the moment but looks really simple and promising! |
Some "undefined reference error" questions are already posted on StackOverflow but I couldn't find solution to my problem. My project contains 5 files: 5.cpp vector_base.h vector_base.cpp vector.h vector.cpp I compile it with: g++ -std=c++11 vector_base.cpp vector.cpp 5.cpp -o 5 And get the following error: /tmp/ccO8NeGJ.o: In function `main': 5.cpp:(.text.startup+0x21): undefined reference to `Vector<int, std::allocator<int> >::Vector(unsigned int, int const&, std::allocator<int> const&)' 5.cpp:(.text.startup+0x2b): undefined reference to `Vector<int, std::allocator<int> >::destroy_elements()' collect2: error: ld returned 1 exit status well, code looks fine for me. Where did I mess up? The code is as follows: 5.cpp #include "vector.h" int main() { Vector<int> a{10, 0}; } vector.h #ifndef VECTOR_H #define VECTOR_H #include "vector_base.h" template<class T, class A = std::allocator<T>> class Vector { private: vector_base<T,A> vb; void destroy_elements(); public: using size_type = unsigned int; explicit Vector(size_type n, const T& val = T(), const A& a = A()); ~Vector() { destroy_elements(); } }; #endif //VECTOR_H vector.cpp #include "vector.h" #include <algorithm> #include <memory> template<class T, class A> Vector<T,A>::Vector(size_type n, const T& val, const A& a) :vb{a, n} { std::uninitialized_fill(vb.elem, vb.elem + n, val); } template<class T, class A> void Vector<T,A>::destroy_elements() { for(T* p = vb.elem; p!=vb.space; ++p){ p->~T(); } vb.space=vb.elem; } vector_base.h #ifndef VECTOR_BASE_H #define VECTOR_BASE_H #include <memory> template<class T, class A = std::allocator<T>> struct vector_base { T* elem; T* space; T* last; A alloc; using size_type = unsigned int; vector_base(const A& a, typename A::size_type n) :alloc{a}, elem{alloc.allocate(n)}, space{elem+n}, last{elem+n} {} ~vector_base() { alloc.deallocate(elem, last-elem); } }; #endif //VECTOR_BASE_H vector_base.cpp #include "vector_base.h" #include <algorithm> template<class T, class A> vector_base<T,A>::vector_base(const vector_base&& a) :alloc{a.alloc}, elem{a.elem}, space{a.space}, last{a.last} { a.elem = a.space = a.last = nullptr; } template<class T, class A> vector_base<T,A>& vector_base<T,A>::operator=(const vector_base&& a) { swap(*this, a); return *this; } I tried compile every cpp file separately and then link all but it didn't work also. | 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.) |
I am trying to ignore the order of the words and searching for the line in one file which has below pattern for example : My Name is ABC. Now I want to change the sequence of words in the same sentence as below : ABC is my name. Can someone please help me on how should I find this line in linux, if the order/sequence of the words keeps changing ? Thanks in advance. | Is there any way to use grep to search for entry matching multiple patterns in any order using single condidion? As showed in for multiple patterns i can use grep -e 'foo.*bar' -e 'bar.*foo' but i have to write 2 conditions here, 6 conditions for 3 patterns and so on... I want to write single condition if possible. For finding patterns in any order you can suggest to use: grep -e 'foo' | grep -e 'bar' # at least i do not retype patterns here and this will work but i would like to see colored output and in this case only bar will be highlighted. I would like to write condition as easy as awk '/foo/ && /bar/' if it is possible for grep (awk does not highlight results and i doubt it can be done easily). agrep can probably do what i want, but i wonder if my default grep (2.10-1) on ubuntu 12.04 can do this. |
I have 5 tower servers (Lenovo system x3500 m5) and they can get a bit noisy in the office. I think it might be the fan for the power unit or cpu. We don't have access to the server room. What solutions are there? | I have recently installed a IBM x45 with two DS4100 (SAN) and due to space constraints it is generating too much noise in adjacent rooms. Are there any good ways to isolate the noise from servers? There doesn't seem to be much vibration, but the majority of the sounds seems to be from the fans and disks. Does anyone have experience with putting sound absorbing materials in server rooms/closets? I'm thinking about covering the surroundings in rubber or something. |
Good morning. Since I started here a lot of computers are getting Windows 10 prompts. I have done everything I can think of to get rid of them but they continue to be a pest. Here is what I have done: Verified not in WSUS Disable next Windows Upgrade in GPO is enabled Set a specific Intranet location for updates in WSUS Created the DisableGWX Key Made sure computers are in correct category in Active Directory to apply GPO When I check the computers 3035583 is installed. I go through the uninstall and reboot but it continues to reinstall automatically. WSUS does not have 3035583 listed and I cannot find it in the catalog either to download and decline it. I dont know what to do from here. | This icon showed up in my taskbar notification area today and I cannot seem to get rid of it: Clicking on it displays the following screen: So how do I disable or remove the "Get Windows 10" icon? |
I recently started using TMUX and found it great i mean for some reason i'm getting addicted to it. But also found 2 itsy bitsy nuisance like 1) While in TMUX if i have a lengthy command and have to jump between words using ctrl+left or ctrl+right arrow key it dont work and i have to travel across character by character 2) While using Vim in TMUX if i press Shift+down or Shift+up arrow key it doesn't work either ... Any clues to solve them .... Thanks in advance ... | I recently started using tmux (was a screen user before) and I'm loving it, except for one small problem. I use emacs within my tmux session and I am used to using Shift-arrow keys to move between emacs windows (not tmux windows). When running within tmux, these bindings seem to stop working entirely (it's like they don't register to emacs at all). If I exit tmux and just run emacs in my shell, they work fine. I'm using iTerm2, ssh'd into a Linux box, running tmux/emacs there. I have the Shift-arrow key bindings set up as follows in my .emacs: (global-set-key "\M-[1;2A" 'windmove-up) (global-set-key "\M-[1;2B" 'windmove-down) (global-set-key "\M-[1;2C" 'windmove-right) (global-set-key "\M-[1;2D" 'windmove-left) When not running in tmux, I can confirm those are the right character sequences for the shift-arrow key combinations by doing C-q in emacs and then pressing the key sequence. Within tmux, even that doesn't work because it doesn't seem to see any input from the shift-arrow keypress (it just sits at the C-q prompt). Looking at the key bindings for tmux, I don't think anything is bound to Shift-arrow keys and even if it was, they would only register after entering the prefix (which is bound to C-o in my case). Any idea on how to make the shift-arrow keys work again within tmux? |
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