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I received on my 14.04 version that I can upgrade IT to 14.10. I accepted everything. The updater did download & install files that it needed and asked me to restart the laptop to complete the update. After that, the system shutdown, Lenovo logo appeared on the screen and it got stuck after the logo with a blank black screen and an underline flickering to my left upper screen. What can I do to fix that? PS: I have tried keeping the Shift while booting to enter in recovery and repair packages, or enter in 'safe mode' even without networking but still no effect. I can't pass that blank screen. | I am trying to boot Ubuntu on my computer. When I boot Ubuntu, it boots to a black screen. How can I fix this? Table of Contents: |
This is the question that has been on my mind lately: If an object A is moving away from an object B which is presumed stationary by A, then the time observed from the perspective of object B will flow (if you will) faster than the time on the object A, correct? However in the same way according to my understanding, if the view points are reversed, then the same effect is to take place from the perspective of the observer in the Object A towards object B. From perspective of observer A (granted there is no point of any observable reference besides object B, object B is moving away and object A is stationary. In which case the time dialation applicable to A and the same effect applicable to B effectively cancel each other out. Would this be an accurate assumption? And if later A or B or both A and B reversed their direction and met, would the time lapsed in each of their measurement be equal to the time either of them have spent in apart and therefore be of equal duration relative to both A and B? | Suppose we have two twins travelling away from each other, each twin moving at some speed $v$: Twin $A$ observes twin $B$’s time to be dilated so his clock runs faster than twin $B$’s clock. But twin $B$ observes twin $A$’s time to be dilated so his clock runs faster than twin $A$’s clock. Each twin thinks their clock is running faster. How can this be? Isn’t this a paradox? |
There are around about getting Ubuntu LTS working with Nvidia 960M cards. Given that there's no definitive answer, I want to offer the following: after testing several distros, Knoppix and Kali both worked without any problems. So, my questions: What is different about Ubuntu that Nvidia drivers don't work out of the box? More importantly, is there an easy way (for an end user) to import whatever's working into Ubuntu 16.04? Edit: Here's what I tried: Purged nvidia-* and reinstalled 364 drivers. Got login loop, followed answers (chown, chmod, rm .Xauthority, and /tmp) Reinstalled xorg and unity. Went to and found the version that works with my card (opted for the Long lived branch). Purged nvidia* (no dash, following a tip in a comment), and reinstalled 367 drivers. Purged nvidia*, reinstalled 370 drivers. Currently stuck at login loop, after following instructions from 2. | I installed or upgraded to Ubuntu 16.04, but I'm having some problems with my graphics card. The display is blank The display flickers Items on the screen do not display correctly Certain programs complain of graphics issues The computer boots to low-graphics mode Your specific issue may not be here, but try the solutions described in the answers anyway. This question is very broad, but each one of these issues likely has one solution. If you are experiencing a login loop, check the last part of my answer. If you experience one of the listed issues and have your own solution (mine didn't work, or there's a faster way), feel free to post another POLITE answer, describing your problem and how you fixed it. Those attempting to install Ubuntu, please refer to the section titled: If you are unable to enter a TTY or are trying to install Ubuntu. |
I am writing a memoir in latex. I have lot of output from Ubuntu terminal and I have tried to put in verbatim, but this is really not pretty. I was wandering if there is a latex tip to put Linux terminal output in latex and make it pretty. | I would like to document work in console while I also think that bitmap images are not the best way to do it. They do not scale well and after all what I am trying to document is text. Therefore I began to wonder whether there is something that could embed text provided into latex formatting which rendered would resemble terminal output. My intention is to document interaction with a microcontroller using serial line terminal emulator. It typically means single line command followed by a few lines of response. |
I'm a bit confused about the whole protected thing in java. If something is protected only the classes within the same package can access it, right? Should we use protected private attributes in a class? And if so, when? | In Java, are there clear rules on when to use each of access modifiers, namely the default (package private), public, protected and private, while making class and interface and dealing with inheritance? |
Hi I am only starting out with Regexs, and am trying to write a regular expression to find string inside curly brackets while keeping curly brackets Text: "This is a {nice} text to search for a {cool} substring". Answer I want: {nice} and {cool} I have already looked through the answer here: This almost does what I want, except that it only returns what's inside the curly brackets. I want to keep the curl brackets. | Unfortunately, despite having tried to learn regex at least one time a year for as many years as I can remember, I always forget as I use them so infrequently. This year my new year's resolution is to not try and learn regex again - So this year to save me from tears I'll give it to Stack Overflow. (Last Christmas remix). I want to pass in a string in this format {getThis}, and be returned the string getThis. Could anyone be of assistance in helping to stick to my new year's resolution? Related questions on Stack Overflow: |
Let $A$ be a commutative ring with unit and $\mathcal{M}$ the set of all the maximal ideals of $A$. I need to prove that $$\mathfrak{m}\not \subseteq \bigcup_{\mathfrak{a}\in \mathcal{M}\setminus \{\mathfrak{m}\}} \mathfrak{a}$$ for every $\mathfrak{m}\in \mathcal{M}$. I get to this statement trying to prove a remark on Neukirch's Algebraic Number Theory that says that if $\mathcal{F}$ is a set of prime ideals of $A$ omitting only finitely many primes, then if $S=(\cup_{\mathfrak{p}\in \mathcal{F}}\mathfrak{p})^c$ we have that the prime ideals of $AS^{-1}$ are of the form $\mathfrak{q}S^{-1}$ where $\mathfrak{q}$ is a prime ideal of $A$ contained in a prime ideal of $\mathcal{F}$ [Page 66]. (I was able to prove that the statement above is equivalent to this) | Suppose $R$ is a Dedekind domain with a infinite number of prime ideals. Let $P$ be one of the nonzero prime ideals, and let $U$ be the union of all the other prime ideals except $P$. Is it possible for $P\subset U$? As a remark, if there were only finitely many prime ideals in $R$, the above situation would not be possible by the "", since $P$ would have to then be contained in one of the other prime ideals, leading to a contradiction. The discussion at the top of pg. 70 in Neukirch's "Algebraic Number Theory" motivates this question. Many thanks, John |
I was recently brushing up on my dynamics, when I saw the interpretation of how a car moves in a circular road. Apparently, the car can stay in a circle due to static friction acting inwards. But I don't seem to understand exactly why this force exists and where it originates. What kind of motion causes it to exist? | When a ball moves to the right, friction acts to oppose the motion, in other words, to the left. However, when a car travels around a bend, the friction acts in the perpendicular direction to the car's velocity and provides the centripetal force. I just cannot understand why friction would act in that direction. |
I see people running shell scripts by typing ./scriptname. Now this seems to be the default way, since I have seen it so often, however occasionally, but not rare, I see them type sh scriptname. Is it just a matter of preference or is there a more significant difference between ./ and sh ? | This may be a silly question, but I ask it still. If I have declared a shebang #!/bin/bash in the beginning of my_shell_script.sh, so do I always have to invoke this script using bash [my@comp]$bash my_shell_script.sh or can I use e.g. [my@comp]$sh my_shell_script.sh and my script determines the running shell using the shebang? Is it the same happening with ksh shell? I'm using AIX. |
People should be treated equally be it rich or be it poor. Is it a correct sentence. If yes what does it mean??? | What does be it mean in this context and what kind of sentence is this? (grammatically) There is no one in our society who is not ethnocentric to some degree, no matter how liberal and open-minded he or she might claim to be. People will always find some aspect of another culture distasteful, be it practices, a way of treating or relatives, or simply a food that they cannot manage to get down with a smile. |
I am doing work for and OS class and for some reason bcc needs a memcpy even though I haven't called it in the code and its unavailable, so I'm rolling my own, however it keeps segfaulting ` void memcpy( void* destination, void* source, size_t bytes ) { size_t i = 0; char* destination__ = ( char* ) destination; char* source__ = ( char* ) source; if( !( destination__ == source__ ) ) { for( ; i < bytes; ++i ) destination__[ i ] = source__[ i ]; } } It seems to segfault and I am not sure why, it does fine when things are malloced but not for something like the following. ` char* foo = "Hello"; char* bar = "Goodbye"; memcpy( bar, foo, 5 ); I have a feeling this is because foo and bar are likely global data, and it has something to do with that but Im not sure. I wouldent be asking except for the fact that I have found other implementations are same/ online It crashes when compiled with regular ol' gcc which Im using to validate outside the OS Im building that has no diagnostics. Im confused as to why this is happening. | The following code receives seg fault on line 2: char *str = "string"; str[0] = 'z'; // could be also written as *str = 'z' printf("%s\n", str); While this works perfectly well: char str[] = "string"; str[0] = 'z'; printf("%s\n", str); Tested with MSVC and GCC. |
It's from the movie "The Mask" Situation: Someone has robbed the bank where Stanley Ipkiss works. Stanley's boss reprimands Stanley for being late: We have a crisis here, and you stroll in an hour late? I would have said that sentence either in Present continuous or in Present Perfect. Self-made: We have a crisis here, and you are strolling/have strolled in an hour late? I've read in one of my grammar books that sometimes we use Present Simple in narratives and anecdotes to highlight an event. Is that the reason the speaker used Present Simple instead of Present Perfect/Present Continuous in the original sentence? Will it be incorrect if I say that sentence in Present Perfect or Present Continuous? Many thanks in advance. | Non-native speakers often get confused about what the various tenses and aspects mean in English. With input from some of the folk here I've put together a diagram that I hope will provide some clarity on the matter. I offer it as the first answer to this question. Consider it a living document. Input is welcome, and good suggestions will be incorporated into the diagram. Nota bene: What this is not is a discussion of whether there are more than two tenses in English. , to which this question is not intended to supply arguments one way or the other. Here, the aim is to provide an overview of what constructions English-speaking people use for conveying information about actions referring to past, present, and future, and to provide it first and foremost to precisely the people who are likely to use "tense" as a catch-all term in their search, rather than to linguists who know better. Breaking News There is now an excellent ELU blog article titled . It is highly recommended reading. |
So, i have this code: \begin{align} S(t+\Delta) &= S(t)-\beta S(t)I(t)\Delta + \phi R(t) \Delta \label{S}\\ I(t+\Delta) &= I(t) + \beta S(t)I(t) \Delta - \gamma I(t) \Delta \label{I}\\ R(t+\Delta) &= R(t) + \gamma I(t)\Delta - \phi R(t)\Delta \label{R} \end{align} I want this with the numbering after every line (i already have that); but i want an '{' in front of the three lines. Is that possible? | I have the following code \begin{align} s'(t) &= -\beta s(t) i(t)\\ i'(t) &= \beta s(t) i(t) - \gamma i(t)\\ r'(t) &= \gamma i(t), \end{align} and I want to enclose this with a bracket like a case, but maintaining the numbered equations. |
Beginner here, but for the life of me I couldn't find an answer to this question after searching and trying to figure it out for myself. I have a very simple app calculating tips, and I'm trying to stop the app crashing when only a decimal place is put into the editText. public void calculate() { float result = 0.0f; float totalBillResult; if(!enteredAmount.getText().toString().equals("")) { NumberFormat numberFormat = NumberFormat.getCurrencyInstance(Locale.getDefault()); if(!enteredAmount.getText().toString().equals(".")){ Toast.makeText(MainActivity.this, "Please enter a bill amount", Toast.LENGTH_SHORT); } enteredBillFloat = Float.parseFloat(enteredAmount.getText().toString()); result = enteredBillFloat*seekBarPercent /100; calculatedTip.setText("Your tip will be " + String.valueOf(numberFormat.format(result))); totalBillResult = enteredBillFloat+result; totalBill.setText("Total bill: " + String.valueOf(numberFormat.format(totalBillResult))); }else { Toast.makeText(MainActivity.this, "Please enter a bill amount", Toast.LENGTH_LONG).show(); } I have tried putting another if statement within the above text to get another toast to show if only a decimal is inputted, and while it doesn't cause any errors it also doesn't do anything, and the app just shuts down when I click to calculate. if(enteredAmount.getText().toString() == (".")) { calculatedTip.setText("Please enter a number."); } I have also tried putting this in the main body of the code to no avail. The logcat is telling me its a NumberFormatException, but after reading this: that was on another post I am none the wiser on how to fix this. Any ideas would be appreciated, and I will edit to add more code if needed Thanks | 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? |
Let $a>1$. If someone could give me an extended prove of that result using only sequence sequences, I would really appreciate it. Thanks in advance. | How do I show that $\ln(x) = \lim_{n\to\infty} n (x^{1/n} - 1)$? I ran into this identity on . I haven't been able to find any proof online and my efforts to get from $\ln(x) := \int_1^x \frac{\mathrm dt}t$ to that limit have been a failure. |
I'm trying to find a solution for a programme which I'm writing. The problem occurs even though I tried to prevent it and I don't seem to be able to find a mistake. This is the ''problematic'' part of my code: if (this.s != null) { if (s.s != null && s.s.sta.length != 0) { for (int n = x; n < s.s.sta.length + x; n++) { this.sos[n] = s.s.sta[n-x]; } x = x + s.s.sta.length; } } I have an array STA which I'm using and a method which gives me the ''s'' neighbour of an object, so s.s is a neighbour of a neighbour.. What I'm trying to do is copy the objects from more than one specific neighbour into one array with many different if sentences. This one is an example but it doesn't work. Thank you and I really hope I get some info because I'm completely lost. | What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them? What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely? |
xampp (on Windows) is working when I have an index.html or index.php file. I am using .php5 as an extension for new files in the project, and would like to use index.php5 for consistency. It is not a big deal, but my syntax highlighter is set up to color .php files differently, so I am reminded that they are older. Can I configure xampp to use index.php5? This is not a duplicate of the other question. The other question is about parsing and running .php5 files in general. This is not a problem on localhost and it is not a problem on any of servers I have running on goDaddy, rackspace and bluehost. The problem is specific to index.php5 - it parses and runs properly when the full name is typed in, but it is not recognized as the default when no file name is entered. Can I configure xampp to DEFAULT to index.php5 given that php5 is working? | I've installed XAMPP Apache server and put my website into htdocs. I've started Apache server. On my website I've got files with extension PHP and with extension PHP5.The difference is that when I type in into browser localhost/file.php - I see a parsed website. But when I type localhost/file.php5 (i have this file on server), than browser asks me if I want to download or open this file. And if I choose open than I see PHP code of file.php5! I've looked into configuration, so: I dont have htaccess file PHPINFO() shows PHP 5 c:\xampp\apache\conf\extra\httpd-xampp is included into configuration and has this on the beginning: AddType application/x-httpd-php-source .phps AddType application/x-httpd-php .php .php5 .php4 .php3 .phtml .phpt I've tried also to put: AddHandler php5-script .php5 AddType text/html .php5 Into httpd.conf, but it does not work for me (no changes). Could you please help me fixing it? I would like to have php5 and php extension files to be opened with php5 parser. |
Statement: Given a connected graph with all edges coloured in one of two colours (red and black), so that for each vertex the number of incident red edges is equal to the number of black edges. Proof: there is a color-alternating path between any pair of vertexes. I had some thoughts on this problem in context of Euler cycle (I can even prove it in the other direction), also have found such theorem: Theorem (2 colors): A 2-edge colored graph has an alternating Euler cycle if and only if the red degree=blue degree for every vertex May be someone knows how to prove it ? | We have connected undirected graph with colored edges in two way (green or blue). And also each vertex have the same number of green and blue edges. How to prove that there are alternate colored (green-blue) path between any two nodes? |
Ok, let's leave the debate of whether friendship breaks encapsulation, and actually try elegantly come up with a coherent design. It is a two fold function: 1) General question on how to implement: public class A { friend class B; } 2) Why do I need this functionality? Some of my classes implement Serializable interface. However, I want to make Serializable methods protected in the Derived class so that I don't expose them to a client (as well as in the documentation -- javadoc). However, internal classes should be able to access them. What is the General way to solve this problem in java? Note: I am using friendship as defined in the current C++ standard. Thanks | I would like to be able to write a Java class in one package which can access non-public methods of a class in another package without having to make it a subclass of the other class. Is this possible? |
Mixamo does a decent job when I need to rig something fast but the fact that all material are gone "compensates" the saved time, forcing me to do it again | I used node textures in a mesh I exported to .FBX. I then imported it into Unreal Engine 4 and it didn't import any textures; I clicked the Upload Textures option in Unreal Engine. Is there something I'm doing wrong or is it Blender? |
I'm new to Java and am trying to learn how to read/write to excel using the Apache POI. As of now, I am just trying to write a new excel file, but even after throwing the IO exception, I am getting a java.lang.ClassNotFoundException: org.apache.xmlbeans.XmlException exception. Here is my code: package ExcelDemo; import org.apache.poi.xssf.usermodel.XSSFWorkbook; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; public class Demo { public static void main (String[]args) throws IOException { try { XSSFWorkbook workbook = new XSSFWorkbook(); FileOutputStream out = new FileOutputStream(new File("C:/Users/colin/IdeaProjects/FinancialIndependence/src/ExcelDemo.xlsx")); workbook.write(out); out.close(); } catch(Exception e){ System.out.println(e); } System.out.println("Excel file outputted"); } } Here is the error I am getting: Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/xmlbeans/XmlException at ExcelDemo.Demo.main(Demo.java:13) Caused by: java.lang.ClassNotFoundException: org.apache.xmlbeans.XmlException at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:582) at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:190) at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:499) ... 1 more Process finished with exit code 1 | I am getting a NoClassDefFoundError when I run my Java application. What is typically the cause of this? |
I've tried to display UTF-8 in the win7 cmd. Currently, I'm using the standard font because as I see with the mysql.exe, it works fine with the characters I'm working with (currently the german umlauts "ßäöüÄÖÜ"). Also, with another font, the same characters appear. But the output of my PHP script displays garbage, e.g. 'ß' for 'ß'. When I pipe the output into a file and open it up with Notepad++, it says the encoding is UTF-8. In php.ini I set UTF-8 as the encoding as well as in the connection to the mySQL database, and in the database itself UTF-8, too. In CMD I tried so far to set the code page to 65001, but nothing changes. edit: my PHP script is saved as UTF-8 as well It seems with latin1, my desired characters can be displayed too and actually it works. But there has to be a way to do it in UTF-8? I can't convert everything to latin1 | We have a project in Team Foundation Server (TFS) that has a non-English character (š) in it. When trying to script a few build-related things we've stumbled upon a problem - we can't pass the š letter to the command-line tools. The command prompt or what not else messes it up, and the tf.exe utility can't find the specified project. I've tried different formats for the .bat file (ANSI, UTF-8 with and without ) as well as scripting it in JavaScript (which is Unicode inherently) - but no luck. How do I execute a program and pass it a Unicode command line? |
I tried this, but it is undefined: alert($(ev.relatedTarget).attr('name')); I have a combobox (textbox and a button), I don't want the code to continue processing if the input goes to its partner control(button). I want to detect from textbox blur that it is leaving the whole combobox not just the textbox. Textbox's blur will naturally trigger when I click its partner button. The only ideal logic I can think of is to detect from textbox's blur that the focus destination is not its partner button, if the relatedTarget is its partner button don't continue processing. | Suppose I attach an blur function to an HTML input box like this: <input id="myInput" onblur="function() { ... }"></input> Is there a way to get the ID of the element which caused the blur event to fire (the element which was clicked) inside the function? How? For example, suppose I have a span like this: <span id="mySpan">Hello World</span> If I click the span right after the input element has focus, the input element will lose its focus. How does the function know that it was mySpan that was clicked? PS: If the onclick event of the span would occur before the onblur event of the input element my problem would be solved, because I could set some status value indicating a specific element had been clicked. PPS: The background of this problem is that I want to trigger an AJAX autocompleter control externally (from a clickable element) to show its suggestions, without the suggestions disappearing immediately because of the blur event on the input element. So I want to check in the blur function if one specific element has been clicked, and if so, ignore the blur event. |
This started happening today for absolutely no reason. Worked perfectly last week. I didn't touch the machine. I have an issue described and need to downgrade in order to be able to upgrade. Currently I'm not able to enter the shell as it exits with error #4 need to upgrade database admin with pdfile version 4.22, new version: 4.5 If I run it with --upgrade I get: ERROR: error: exception cloning object in admin.system.users system.users entry must have either a 'pwd' field or a 'userSource' field, but not both obj:{ _id: "nod$ exception in initAndListen: 2 system.users entry must have either a 'pwd' field or a 'userSource' field, but not both, terminating I'm trying sudo apt-get install mongodb-10gen=2.2.7but it doesn't work because that version is missing - I dont know if there is any way to install legacy versions? Can anyone direct me to a command I can use to install version 2.2.7? | This started happening today for absolutely no reason. Worked perfectly last week. I didn't touch the machine. I have an issue described and need to downgrade in order to be able to upgrade. Currently I'm not able to enter the shell as it exits with error #4 need to upgrade database admin with pdfile version 4.22, new version: 4.5 If I run it with --upgrade I get: ERROR: error: exception cloning object in admin.system.users system.users entry must have either a 'pwd' field or a 'userSource' field, but not both obj:{ _id: "nod$ exception in initAndListen: 2 system.users entry must have either a 'pwd' field or a 'userSource' field, but not both, terminating I'm trying sudo apt-get install mongodb-10gen=2.2.10but it doesn't work. Can anyone direct me to a command I can use to install version 2.2.10? |
In the Harry Potter series Harry's parents go into hiding by using a Fidelus Charm which needs a secret keeper. So they chose Peter Pettigrew as their secret keeper and were betrayed. Why didn't they make each other their secret keeper? James could have made Lily secret keeper (of his and Harry's secret) and Lily could have made James (of her and Harry's secret) their secret keeper. So there wouldn't have been any chance of third person betraying them. | Why wasn't James Potter his own Secret Keeper? The whole thing came about because Potters chose the wrong Secret Keeper (who betrayed them) for the Fidelius Charm on their house. Why didn't James just make himself a Secret Keeper? We know that it’s possible from Deathly Hallows: (Bill and Arthur Weasley are their own Secret Keepers). “I’ve been getting them all out of the Burrow,” Bill explained. “Moved them to Muriel’s. The Death Eaters know Ron’s with you now, they’re bound to target the family – don’t apologize,” he added at the sight of Harry’s expression. “It was always a matter of time, Dad’s been saying so for months. We’re the biggest blood traitor family there is.” “How are they protected?” asked Harry. “Fidelius Charm. Dad’s Secret-Keeper. And we’ve done it on this cottage too; I’m Secret-Keeper here." |
I just would like to ask when can i reapply for visiting visa in the Netherlands? I have been there last December 19,2016 til February 18,2017. I lately just read about "90 days in 180 days period". What does that mean? I checked my recent visa and saw the dates from December 17,2016 til April 1, 2017( 105 days). Can i apply for reentry visa this May? I hope you can help me out. Thanks in advance! | I have searched the web a lot and could not find an answer that fits my situation. Here are two links that are quite contradictory: My situation: I've visited Portugal in December 2012 for 29 days on a Schengen visa valid from December 1st, 2012 to February 1st, 2013 for research purposes (I am a Ph.D. student). I want to visit Sweden from February 10th, 2013 to May 10th, 2013 (89 days). I have applied for a Schengen visa again (for research). How will the 90/180 rule work in my situation? |
I am working with some gstreamer based application and some other streaming stuff and I came to some confusion: What is difference between libav and ffmpeg? I found no explanation what are they and how they differ. Even more one have tool called ffmpeg while other does have the same thing too. Also even those project logos are the same. And to make matters worse even external application who uses them misnames them, mix them (gstreamer-0.10 refers to ffmpeg, while gstreamer-1.0 refers to libav). Is there easy way to find out which library is really needed and used by application? Is there any technical (non political software licensing nonsense) difference why projects split away and I should be aware of when I should work with them? Update: Someone in comments put the links to questions related to history of both libraries and usefull info. However I doubt that my question is exact duplicate: I am asking method itself to detect libraries. List or something like that, caveats or even hints how libraries work different one from another, not opinion which is better, neither how licensing communities differ one from another. | From what I've seen it looks to me like Libav's avconv is thought to become a successor of ffmpeg — is that correct? If that's true, why is that so? What exactly is libav doing better and why would I want to choose it over ffmpeg? I came to this "issue" while installing Ubuntu 12.04.1 LTS in a VM and when I've installed ffmpeg it came up with a message telling mit ffmpeg is deprecated and I first thought "wtf?". If I use avconvWill I be able to migrate my scripts depending on ffmpeg more or less easy to libav? I'm mostly using it for writing meta data and doing audio conversion (wav, flac, vorbis, mp3, aac). |
I have two external hard discs on an OpenSUSE 13.1 system. On one I have created a partition structure: An encrypted LVM partition (LUKS) Several volumes (10) on this LVM partition, some formatted with xfs, some with ext4. sdf 8:80 0 5,5T 0 disk └─sdf1 8:81 0 5,5T 0 part └─extern-2-crypt 253:5 0 5,5T 0 crypt ├─extern--2-nelson--home 253:10 0 8G 0 lvm /extern/nelson/home ├─extern--2-lucien--boot 253:11 0 300M 0 lvm /extern/lucien/boot ├─extern--2-nelson--root 253:12 0 11,5G 0 lvm /extern/nelson/root ├─extern--2-nelson--space 253:13 0 90,1G 0 lvm /extern/nelson/space ├─extern--2-lucien--backup 253:14 0 400G 0 lvm /extern/lucien/backup ├─extern--2-lucien--home 253:15 0 20G 0 lvm /extern/lucien/home ├─extern--2-lucien--raid 253:16 0 3,5T 0 lvm /extern/lucien/raid ├─extern--2-lucien--root 253:17 0 8,5G 0 lvm /extern/lucien/root └─extern--2-lucien--space 253:18 0 30G 0 lvm /extern/lucien/space How can I replicate this structure easily including the LVM config from one disc to the other (with only one disc running at the same time)? I know of sgdisk (8) and parted (mentioned in ), but that covers only the partition, not the LUKS information and certainly not the LVM config. | I want to take a backup of the whole partition layout of a hard drive, including logical drives, so that I can restore that layout to another disk. I do not want to copy the contents of the partitions, only the layout. For the primary and extended partitions, it's easy: dd if=/dev/sda of=partitiontable.bin bs=1 skip=446 count=64 # backup dd if=partitiontable.bin of=/dev/sda bs=1 seek=446 count=64 # restore But when it comes to the layout of the logical partitions, I wonder if there exists among the standard tools a similar way of saving the layout? I guess the main problem is finding the offsets to the locations of the EBRs, because with that, dd will do the rest. Keep in mind I need to be able to put everything back to a (possibly) blank disk and thereby restore the same layout. Using partitioning tools like fdisk or parted is fine, but I must be able to automate their use (scripting) and they should not depend on any X-related packages -- command line only. My backup plan is doing it manually in a little python script using the struct module, but I rather hoped there was an easier way. |
Phantasmal Force 2nd-level Illusion Casting Time: 1 action Range: 60 feet If I were to cast this spell, and either I or the target otherwise become greater than 60 feet away from each other during the duration, would the spell fail/end? There is precedent in other spells like Witch Bolt which specifically says the spell ends if the target is outside the spell's range, but Phantasmal Force never specifies such a condition. | Does going outside the range of the spell or breaking line of sight between the caster and target break concentration or otherwise affect control over the spell? For example, a Heat Metal spell has a range of 60 ft. If I cast the Heat Metal spell on a an armored foe, and that foe runs outside the range of the spell (60 ft), or around the corner, does that break concentration and end the spell? Heat Metal also allows you to use a bonus action to cause the 2d8 of damage — would exercising that option be prevented by being out of range or line of sight? |
Using the axiom of choice, or more directly, the statement that every linearly independent set of vectors in a vector space may be extended to a basis, it is easy to prove that every short exact sequence of vector spaces splits. Is the converse also true? Over ZF, does the splitting of each short exact sequence of vector space suffice to prove that every vector space has a basis? One thing I tried was the following: suppose that $V$ is a vector space over $k$, and let $k[V]$ be the vector space freely generated by the elements of $V$, and let $k[V] \to V$ be the "projection". Then you get a section $V \to k[V]$... but it doesn't seem there's any way to guarantee the image of the section contains any standard basis vectors. | Let say we live in the category of vector spaces over $\mathbb{R}$ or $\mathbb{C}.$ Here are three sentences: Axiom of choice Every vector space has a base. For every vector space $V$ and its subspace $E\subset V$ there is a subspace $F\subset V$ such that $V=E\oplus F.$ I know how to prove that (1)->(2)->(3). How about the inverese? Do (2)->(1) and (3)->(2) hold? If this is not the case, then is there some weaker version of AC which imply (3)? |
Statement: Let $n$ and $m$ be two irrational numbers. Then $n^m$ is always irrational. I think this statement is correct, otherwise can someone give me a counterexample? Thanks! | Can an irrational number raised to an irrational power be rational? If it can be rational, how can one prove it? |
$$\int \sqrt{1+x^2}\,dx$$ I've tried some step-by-step calculators, but what they give is way beyond my level. Is there any "simple" way to solve this? | $$\int\sqrt{x^2+1}dx$$ I've been attempting this problem for days and I've made very little progress. I understand that I should substitute $x=\tan(x)$ and $dx=\sec^2(x)dx$ but beyond that I am very much lost. |
I have two files: file 1: a,txt1,v1 b,txt2,v2 c,txt3,v1 d,txt4,v2 file2: a,txt5,v2 b,txt6,v1 xc,txt7,v1 xd,txt8,v2 I want to refine the files. I only need the lines where the 1st column in file1 has match in file2. The new file1 should contain: a,txt1,v1 b,txt2,v2 Similarly, file2 should be refined to contain only lines where there is a match in the 1st column with file1. So file2 should be: a,txt5,v2 b,txt6,v1 | I use Ubuntu 18 and have little experience with Linux commands. I have two files: file 1: a,txt1,v1 b,txt2,v2 c,txt3,v1 d,txt4,v2 file2: a,txt5,v2 b,txt6,v1 c,txt7,v1 d,txt8,v2 I want to print the 1st and 3rd column values where the the 1st column value is identical and the 3rd column value has changed from v1 to v2. So my expected output should be: a The second query is for the 3rd column values that has changed from v2 to v1. So my expected outcome: b |
I have a problem displaying "€" in my html... My database field has collation "utf8_general_ci" I fetch the data like that into an javascript variable: $query = mysqli_query($con, "SELECT * FROM Table WHERE Id = '1'"); $data = mysqli_fetch_assoc($query); $data = json_encode(utf8_encode(($data["Field"]))); As I want to echo $data... I get Umlauts see "ÄüÖü" and other chars like " ', #@&" etc. BUT I DON'T SEE THE € SIGN..... it get's displayed as a ? ( Not that in a rectangle... just a normal ?) Can anyone help please? Btw, that's my header: header("Content-Type: text/html; charset=utf-8"); | 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. |
I just made an edit and saved it without giving it an edit summary. The default summary was added 24 characters in body I made another edit to the same post within 5 minutes, this time changing the automatic edit summary, however, when I viewed the edit, the original automatic summary remained. I suggest that we be allowed to edit the summary while we're within 5 minutes of posting the edit. It has been suggested that users can make two edits to change the summary: the first by making a superfluous change, the second by undoing the change and changing the summary at the same time. This is counterintuitive and surprising behaviour. A user only has 5 minutes to change an edit before it becomes a new edit, and in that period they should be able to do anything they could have done on the first edit. This feature was first suggested in early 2011 and was very popular, yet was never done. If the reason it hasn't been implemented is to avoid trivial edits, then the workaround (which didn't work for me) simply doubles the number of trivial edits needed to get the job done. | It often occurs to me to add an edit summary to a question-edit immediately after submitting the edit, especially if the changes aren't obvious (formatting etc.). So I: Click "edit" again. Fill in the summary Click on "Save Edits". The 'edit' (no actual change has been made to the title/body/tags) is accepted, but the summary doesn't show up, i.e. it is silently rejected. I don't think it should work this way because the summary has been added by the original editor within the original edit's edit-window. In fact if I remember correctly, it to used to work as expected earlier; so perhaps this is a recent change. |
I have recently upgraded my PC with a GTX 1080 Ti graphics card, and an i7 7700k Kaby Lake CPU, now however, I can't boot at all into my Linux partition, nor can I even run a live CD to customize the install to use non-free drivers. I tried on another PC to make sure my media wasn't going bad, and I was able to boot into Linux successfully and run the Live CD. Is there anyway to boot a live CD on this hardware and install Linux? I do also have a DisplayPort out on my motherboard for iGPU if that is necessary. | Today I tried several times to install Ubuntu but I have some GPU problems. I have a bootable stick. When I boot in UEFI mode all its normal but the installer isn't able to install the boot loader. When I boot in leagacy mode I'm able to install Ubuntu but only when I unplug my GPU GTX 1070. When I don't do that, I get an this initialization error from the installer: 3.021954] nouveau 0000:01:00.0: unknown chipset (134000a1) I installed Ubuntu normally without the GPU. I installed the drivers, rebooted, shut down, pluggeed in the GPU and tried to boot but it got stuck at: /dev/mapper/isw_bdifbbjbai_Raid0p3: clean, 191449/8855552 files, 1677252/34500448 blocks What should I do? When I unplug the GPU I can boot easily, but I need my GPU! :D My PC has a GTX 1070 GPU, i7 4790K CPU, and two hard drives: 250 GB M.2 SSD, which contains Windows 10 and its boot loader. 2 TB RAID-0 WD, with 1,85 TB for Windows 10 files and 150GB where I installed Ubuntu and its boot loader. |
I use a quite complicated way to make my citation, as I need to use the same citation as a reference in different places in my text. Now I got the correct way of showing the citation in footnote, but each citation has 2 numbers, and the number of the citation is not in order (the one with squared brackets). It comes out like 1[3], 2[1], 3[4], 4[2] I want them show as (this problem has been solved with sorting=none) [1],[2],[3],[4] And how to remove the number 1 before [1]? Is that possible to set the referenced citation also as superscript inside the text? In order to keep reference citation work, I keep the script for footpartcite and partcite. Thank you! \documentclass[a4paper, 12pt, headsepline,DIV=12,twoside]{report} \usepackage[english]{babel} \usepackage{mathptmx} \usepackage[T1]{fontenc} \usepackage[utf8]{inputenc} \usepackage{parskip} \usepackage{filecontents} \usepackage[backend=bibtex,style=numeric,natbib=true]{biblatex} \usepackage{textcomp} \usepackage{csquotes} \begin{filecontents}{\jobname.bib} @Electronic{unintentional, Title = {Accidents or Unintentional Injuries}, Author = {{National Center for Health Statistics}}, URL = {http://www.cdc.gov/nchs/fastats/accidental- injury.htm}, urldate = {2016-08-10},} @Book{HP, Title = {Harry Potter and the Philosopher's Stone}, Author = {{Rowling,J. K. }}, Date = {1997}} @Misc{ASH, Title = {Automotive Safety Handbook}, Author = {{Seiffert, Ulrich; Wech, Lothar}}, Date = {2003}, Editor = {SAE International}, Note = {pp. 91, 96, 97}} @Electronic{CrashStatistic, Title = {Annual Global Road Crash Statistics}, Author = {{Association for Safe International Road Travel}}, Date = {2016-07-16}, Url = {https://asirt.org/initiatives/informing-road-users/road-safety-facts/road-crash-statistics}} \end{filecontents} \usepackage{xcolor} \usepackage{hyperref} \hypersetup{colorlinks,linkcolor={black},citecolor={blue!50!black}} \DeclareCiteCommand{\footpartcite}[\mkbibfootnote] {\usebibmacro{prenote}} {\usebibmacro{citeindex}% \mkbibbrackets{\usebibmacro{cite}}% \setunit{\addnbspace} \printnames{labelname}% \setunit{\labelnamepunct} \printfield[citetitle]{title}}% {\addsemicolon\space} {\usebibmacro{postnote}} \DeclareMultiCiteCommand{\footpartcites}[\mkbibfootnote]{\footpartcite} {\addsemicolon\space} \DeclareCiteCommand{\partcite} {\usebibmacro{prenote}} {\usebibmacro{citeindex}% \mkbibbrackets{\usebibmacro{cite}}% \setunit{\addnbspace} \printnames{labelname}% \setunit{\labelnamepunct} \printfield[citetitle]{title}% {\addsemicolon\space} {\usebibmacro{postnote}} \DeclareMultiCiteCommand{\partcites}{\partcite}{\addsemicolon\space} \addbibresource{\jobname.bib} \begin{document} Each citation has two numbers.\footpartcite{unintentional} And the order of citation is not correct. \ref{ftn:unintentional} I dont know how to put unsrtnat style inside my preamble, because the system said it´s not existing.\footnote{\label{ftn:unintentional}\partcite{unintentional}} And I have tried to define natbib separately \ref{ftn:unintentional} But the system says I have already defined it with usepackage {biblatex}\footnote{\label{ftn:HP}\partcite{HP}} The citation number inside text is not correct,\footpartcite{CrashStatistic} because only 4 citations have been used here \footpartcite{ASH} Does anyone know how to solve them?\ref{ftn:HP} \printbibliography \end{document} | I have read the posts related to bibliography topic, but they cant really help me. I hope someone can really help me for these questions, as I have to hand it in on next monday... I have also written all my questions in my MWE, so if you want to, you can read my script directly to save sometime! In order to keep reference citation work, I keep the script for footpartcite, partcite, and footnote. How to list the bibliography alphabetically? Now I got the correct way of showing the citation in footnote, but each citation has 2 numbers, it comes out like 1[1], 2[2], 3[3], 4[4] I want it show as [1],[2],[3],[4] how to remove the number 1 before [1]? I have used \footnoteref instead of \ref, because \ref doesnt appear as superscript in the text, if you know how to set it as a superscript of the text, then it will be even better, because it can be written inside a caption directly! Solution for single question is also really appreciated! Thank you very much! \documentclass[a4paper, 12pt, headsepline, DIV=12,twoside]{report} \usepackage[english]{babel} \usepackage{mathptmx} \usepackage[T1]{fontenc} \usepackage[utf8]{inputenc} \usepackage{parskip} \usepackage{filecontents} \usepackage[backend=bibtex,style=numeric,sorting=none,natbib=true]{biblatex} \usepackage{textcomp} \usepackage{graphicx} \usepackage{csquotes} \begin{filecontents}{\jobname.bib} @Electronic{unintentional, Title = {Accidents or Unintentional Injuries}, Author = {{National Center for Health Statistics}}, URL = {http://www.cdc.gov/nchs/fastats/accidental- injury.htm}, urldate = {2016-08-10},} @Book{HP, Title = {Harry Potter and the Philosopher's Stone}, Author = {{Rowling,J. K. }}, Date = {1997}} @Misc{ASH, Title = {Automotive Safety Handbook}, Author = {{Seiffert, Ulrich; Wech, Lothar}}, Date = {2003}, Editor = {SAE International}, Note = {pp. 91, 96, 97}} \end{filecontents} \DeclareCiteCommand{\footpartcite}[\mkbibfootnote] {\usebibmacro{prenote}} {\usebibmacro{citeindex}% \mkbibbrackets{\usebibmacro{cite}}% \setunit{\addnbspace} \printnames{labelname}% \setunit{\labelnamepunct} \printfield[citetitle]{title}}% {\addsemicolon\space} {\usebibmacro{postnote}} \DeclareMultiCiteCommand{\footpartcites}[\mkbibfootnote]{\footpartcite} {\addsemicolon\space} \DeclareCiteCommand{\partcite} {\usebibmacro{prenote}} {\usebibmacro{citeindex}% \mkbibbrackets{\usebibmacro{cite}}% \setunit{\addnbspace} \printnames{labelname}% \setunit{\labelnamepunct} \printfield[citetitle]{title}% \newunit \printfield{year}} {\addsemicolon\space} {\usebibmacro{postnote}} \DeclareMultiCiteCommand{\partcites}{\partcite}{\addsemicolon\space} \usepackage{remreset} \makeatletter \@removefromreset{footnote}{chapter} \newcommand\footnoteref[1]{\protected@xdef\@thefnmark{\ref{#1}} \@footnotemark} \makeatother \addbibresource{\jobname.bib} \begin{document} Q1: Each citation has two numbers. \footnoteref{ftn:unintentional} How to remove the number in front of the squared brackets. \footnoteref{ftn:unintentional} Q2: know how to list the bibliography alphabetically. \footnote{\label{ftn:unintentional}\partcite{unintentional}} Q3: how to put a footnoteref inside of a caption? because if I put it inside a caption of a table or figure, it will show error, but if I put it outside the caption bracket, \footpartcite{ASH} the footnoteref will show in the next line rather than as superscript of the caption. \footnote{\label{ftn:HP}\partcite{HP}} \begin{figure}[h] \includegraphics[width=\textwidth]{example-image-a} \caption{I am a figure}\footnoteref{ftn:HP} \end{figure} Does anyone know how to solve them? Thank you very much! \printbibliography \end{document} |
In the Wikipedia article for skew symmetric matrixes the following propert is stated: If A is a real skew-symmetric matrix, then I + A is invertible, where I is the identity matrix. However I haven’t been able to find a proof of this or why it does not apply to complex matrices. This is different from the one where I - A is invertsble because this is I + A | Let $A\in M_{n\times n}(\mathbb{R})$ be a skew-symmetric matrix. show that $A-I$ is invertible and $(A-I)^{-1}(A+I)$ is an orthogonal matrix. $|A-I|=|(A-I)^T|=|-(A+I)|=(-1)^n|A+I|$ I have no clue to solve this problem, I appreciate any help. |
Can X11 and Wayland be used at the same time? My Display Server of choice is X11, and I want to use an application that only supports Wayland - would that be possible at all? | Is there's wayland server running as X11 client? Like but reversed. |
"Biweekly" means every two weeks. What's the term for something that happens twice a week? We need to have _______ meetings until this crisis is over. | We have two words for events occurring in periods of years - biannual meaning twice a year, and biennial meaning once every two years. However, my colleagues talk about having meetings biweekly. This causes a lot of confusion, since it can mean either once every two weeks or twice a week. We can use fortnightly to indicate once every two weeks and help disambiguate that way. Are there any other words we could use which could help, particularly words which mean "twice a week"? I'm looking particularly because some of my colleagues speak English only as a second language, and find fortnightly difficult to remember. |
I'm php web developer and got stuck with a little problem. I'm Using code-igniter framework. The Problem is that all emails emails are going to junk folder only in outlook case. But in case of gmail, the code is working properly. all emails are going to inbox folder. Is there any security issues between both of them.? Need Suggestions Please. Thanks ab | This is a tricky one and I've always relied on techniques, such as permission-based emails (i.e. only sending to people you have permission to send to) and not using blatantly spamish terminology. Of late, some of the emails I send out programmatically have started being shuffled into people's spam folder automatically and I'm wondering what I can do about it. This is despite the fact that these particular emails are not ones that humans would mark as spam, specifically, they are emails that contain license keys that people have paid good money for, so I don't think they're going to consider them spam I figure this is a big topic in which I am essentially an ignorant simpleton. |
Can I invert the D+ and D- in a USB OTG connection?, would it work? I know that in some protocols like PCIe you can do it, but Im not sure about usbOTG. | I heard that D+ and D- are differential signals, does it matter if I swap them when connecting a USB device to the computer? |
I am new to Sharepoint. I am using Sharepoint Designer 2013. Need pointers/sample code to accomplish the below. I have to 2 custom Lists like below. Ex: State (Custom list1) State AP UP MP City (Custom list2) City State Desc KNR AP WL UP NZB AP SRC MP HZB UP I have to create a page, where I have to load dropdown values from 1st list. When I selected the value from dropdown, I should get all the selected dropdown value related data from 2nd list in a table/grid, where I have to edit the table and save. | I'm trying to implement cascading drop down for list in SharePoint online I have 3 different list with name Countries , States, cities. and the master list Address in which I have Fields Country , State, City. I'm trying to display Sates for selected country. and City for selected States in SharePoint Online list |
I am getting this error. How can I upgrade now? | When updating, I get the following error message: W: The repository 'http://ppa.launchpad.net/mc3man/trusty-media/ubuntu xenial Release' does not have a Release file. Here, I find another statement on this error: This recommends removing certain PPAs; and, I'm not sure if I should do that since it might mean not getting the updates that I need. Is this what I should do? |
$f: \mathbb{C} \rightarrow \mathbb{C}, \; z \mapsto f(z) := \frac{z^2}{1+|z|}$ How would I go about proving this is uniformly continuous? Currently I have only practically dealt with analyzing continuity of real functions. Here's my approach: $\forall \epsilon > 0 \; \exists \delta > 0 \; \forall z,z_0 \in \mathbb{C}: |z-z_0| < \delta \implies |f(z) - f(z_0)| < \epsilon$ Let $\epsilon > 0$ and $|z-z_0| < \delta$. We don't know yet whether $\delta$ exists or its value. Looking at $|f(z) - f(z_0)|$ we get $|\frac{z^2}{1+|z|} - \frac{z_0^2}{1+|z_0|}|$. Now I know that I will need to estimate this term somehow to eliminate $z_0$ such that our $\delta$ is only dependent on $\epsilon$. First thing I thought about was bringing both summands down to a common denominator such that we have $$\frac{|z^2(1+|z_0|) - z_0^2(1+|z|)|}{|(1+|z|) (1+|z_0|)|}$$ So now when we multiply this out we get $$ frac{z^2 - z_0^2 + z^2|z_0| - z_0^2|z|}{(1+|z|) (1+|z_0|)} < \frac{\delta + z^2|z_0| - z_0^2|z|}{(1+|z|) (1+|z_0|)} $$ My lectures have just introduced this topic and I don't really know yet how to go about these proofs. Thanks for any help! | I tried using the definition of the continuity to try and find a $\delta$ but I got stuck here $$ |f(w) - f(z)| = |\frac{w^2 \cdot (1+|z|) - z^2 \cdot (1+|w|)}{(1+|w|)\cdot(1+|z|)}|$$ What can I do to find a suitable $\delta$ that would end my proof? |
We all know , but it seems the problem is people not reviewing enough. Whenever I had time, I would go through all 40 that I was given, but by then I wanted to do more. Would raising that limit of 40 and not counting Close Votes queue votes towards your daily close vote allowance help? | Today, the size of the close-votes queue is 55k questions and growing. Is that a problem? Which action could be taken to clean it up? It seems to be growing faster than Stack Overflow members are capable to handle it. |
I have installed Ubuntu 20.04 on an external HDD, it's been a huge pain. I've followed a a guide on internet, where it was said that giving 40GB of space for the root partition would've been enough, now I'm seeing that with less than a quarter of the program that I need it's already quite full. I don't know if I should resize some partiton (and how) or maybe merging the two partition (/home and /). Please don't tell me to redo the installation with different partition because it was a huge pain. | Previously, I have installed Windows 7 on my 320 GB laptop with three partitions 173, 84 and 63 GB each. The 63 GB partition was where the Windows was installed. The rest were for file containers. Now I changed my OS to Ubuntu 12.04 LTS. I installed Ubuntu by replacing the entire Windows 7 on the 63 GB partition. The rest of the partitions remain as an NTFS Windows partition and I can still access them both (the 173 and 84 GB partitions). Now I want to change the two partitions of Windows into an Ubuntu format partitions plus most importantly, I want to extend the 63 GB partition to more than a 100 GB because at the moment I am running out of disk space. Whenever I try to install any application, especially using wine, it always complains for a shortage of disk space. How do I do the extending activity before I entirely format my laptop again and lose all the important files on my partitions? |
please see the scrnsht i new to this new it says using git add .a is for adding all files in CURRENT DIRECTORY and git add -A is for adding all files in CURRENT REPOSITORY. Is directory different from repository or ONE AND THE SAME?Thanks. | The command git add [--all|-A] appears to be identical to git add .. Is this correct? If not, how do they differ? |
I want to ask, why didn't Stack Overflow register my visit on Saturday? I'm 100% certain I was logged in on that day. I'm asking because it broke my consecutive days logins. | Yesterday I visited Stack Overflow and had 13 consecutive days visited. Today, I visited and had 1. Is this a bug? Why did it reset? |
I am trying to get out of low priority and they said I needed to play 5 matchmade games without leaving and I would like to know if Tutorial or Practice tool counts as a matchmade game and I would like to know what does count in a matchmade game. | So recently (or maybe not recently, I just started playing again) Riot implemented a . I'm still really confused how it works, but I managed to obtain another box besides the one that they gave me as intro-freebee. Now I think I need a key, but i don't know how to earn one. The article i posted in that link above says: Earn keys as rewards for winning any matchmade games or by purchasing them at the store for 125 RP. Keys unlock chests through Hextech Crafting. But I don't know what a "matchmade" game is officially. says: anything that uses the matchmaking system, so custom games are out, and that's it but that doesn't help because I still don't know what the matchmaking system is. Aren't all games made by matching? if so, why didn't i receive keys for winning a normal-draft game? And I have RP but whats the point of spending it on this if i can just win it somehow? |
Suppose $p$ is an odd prime. Show that $1^{p-1} +2^{p-1}+ \ldots +(p-1)^{p-1}\equiv -1\pmod p$. I think I need to use Wilson's Theorem on this but I'm not sure how. I believe I am suppose to factor it somehow too but also I'm lost at this point. | Show that $$1^{p-1} + 2^{p-1} +\ldots + (p-1)^{p-1} \equiv -1 \mod p$$ So, I use Fermat's little theorem, that is if $p$ does not divide $a$, then $a^{p-1}$ is congruent to $1$ (mod $p$). But I'm still confused. If $1^{p-1}$ is congruent to $1$ (mod $p$), $2^{p-1}$ is congruent to $1$ (mod $p$), and $p$ does not divide $p-1$, so $(p-1)^{p-1}$ is congruent to $1$ (mod $p$). How does that equal $-1$ (mod $p$)? |
There seems to be a lot of questions / answers about doing the reverse, but not as much info for USB -> DVD. Problem I created a bootable USB drive using YUMI. The USB drive is working great, and contains the following: Linux Mint 13 Linux Mint Debian Debian 6 Ubuntu 12.04.1 Fedora 17 A bit of a mix of DVD and Live versions. I have a spindle of DVD+R DL blank DVD's. I would like to create a bootable .iso from this USB drive so I can burn multiple copies of it to pass around to friends! I've created an iso using Folder2ISO, but it coastered my DVD because it wasn't bootable. I don't really want to waste a whole spindle! How would you go about doing such a thing? | I have an iso file of operating system's set up. Now, I don't have dvd burner right now. But the alternate - 4gb pen drive is available. If I copy entire iso file to pen drive, Can my system boot through pend drive? |
Here on the Internet, we see many ads promoting software products which can enhance your Internet speed. I wonder, how could this be? Imagine that you are using a 1 Mbps Internet connection, and the highest speed speed you can get from it is nothing above the limit. The Internet services are programmed to transmit certain-sized data packets at a certain rate. So when we can't do anything physically (like manipulating the line and such), how come those software developers claim that their products could enhance the Internet speed? Edit : Thanks to all people.I have got my answer. | Are applications that claim to improve web speeds effective? If so, how? I would have guessed they were scammy, but I suppose if they can reroute traffic to a closer datacenter it might be possible? |
I am looking for some help with Regex syntax. I tried many ways to make the syntax for this case, but nothing seems to work. Could someone help me with this? So I have a case where I am trying to replace everything before the "." symbol in this string, example_ so.myname I successfully removed all the strings before the "." using this expression: var removeStrBeforeDot = params.value.replace(/(\<b\>|\<nobr\>)[a-z]*\./g, ""); removeStrBeforeDot = removeStrBeforeDot.replace(/\(.*\)\<\/b\>/g, " "); But the issue with this expression is, this works when there is only letters before the dot and doesn't work when there are symbols like , space, etc. Like for example, example so.myname has a space and a "_" which is not working in this case. What I like to do is keep it more generic and remove any string before the "." to be removed. Any help could be greatly appreciable. Thanks! | See code: var file1 = "50.xsl"; var file2 = "30.doc"; getFileExtension(file1); //returns xsl getFileExtension(file2); //returns doc function getFileExtension(filename) { /*TODO*/ } |
Suppose $$A\neq\emptyset$$ Since, $$\emptyset\subseteq A * A$$ the set $$R=\emptyset$$ is a relation on A. Is $R$ reflexive? symmetric? transitive? I remember hearing something can be "vacuously" true. So the empty set would be reflexive, symmetric and transitive because it doesn't meet the definition? So there is no $(x,x)$ that can exist in $R$ therefore vacuously reflexive. There is no $(x,y)$ that can exist in $R$ therefore vacuously symmetric. There is no $(x,y)$ that can exist in $R$ therefore vacuously transitive. Is my reasoning correct here? | Question: Let $R$ be a relation on a set $A$. Prove that if $A$ is non-empty, the empty relation is not reflexive on $A$. the empty relation is symmetric and transitive for every set $A$. My Solution: For a relation to be reflexive: For all elements in A, they should be related to themselves. ($x$ $R$ $x$). Now in this case there are no elements in the Relation and as A is non-empty no element is related to itself hence the empty relation is not reflexive. Now for a set to be symmetric and transitive: As these are conditional statements if the antecedent is false the statements would be true. And as the relation is empty in both cases the antecedent is false hence the empty relation is symmetric and transitive. (I just want to know if my solutions are correct. - I've given brief solutions without using any notation here.) |
I understand Current density $J =n e v$ [$n=$ carrier concentration per unit volume, $e=$ charge on electron, $v=$ drift velocity] Which is independent of area of cross section of wire (and hence the diameter) However, the book practical electronics for beginners quotes that: Current density within a copper wire increase as the diameter of the wire decrease. Is the book mentioning about varying cross section in the same wire? If yes then can you please explain how does current density increase in a smaller diameter wire? | I am confused whether drift velocity depends upon area or not . I checked answers for this question but all of them were cancelling each other out . from the equation $$I = neAv$$ It is clear that drift velocity should depend upon area but at the same time don't you think that by increasing the area of cross section of a conductor should have resulted in increase in drift velocity please help me out with it in detailed answer of how should i go with all the possible cases and explanation ,thanks :) |
(PHB 215) states: If a creature hits you with a melee attack while you have these hit points, the creature takes 5 cold damage. Since it doesn't specify that it has to be a weapon attack, does it also work for melee spell attacks? Specifically, would it work against (PHB 278)? | The spell says: The spell captures some of the incoming energy, lessening its effect on you and storing it for your next melee attack. You have resistance to the triggering damage type until the start of your next turn. Also, the fist time you hit with a melee attack on your next turn, the target takes an extra 1d6 damage of the triggering type, and the spell ends. The cantrip says: Lightning springs from your hand to deliver a shock to a creature you try to touch. Make a melee spell attack against the target. You have advantage on the attack roll if the target is wearing armor made of metal. On a hit, the target takes 1d8 lightning damage, and it can’t take reactions until the start of its next turn. If I absorb fire damage with absorb elements, would I be able to add an extra 1d6 fire damage to my next shocking grasp attack? |
Recently in an episode of 'House of cards' they bring up the joke "Two freshmen girls are moving into their dorm room together. One of them's from Georgia, one of them's from Connecticut. The girl from Connecticut's helping her mother put up curtains. Girl from Georgia turns to them and says, "Hi. Where y'all from?" Girl from Connecticut says, "We're from a place where we know not to end a sentence with a preposition." The girl from Georgia says, "Oh, beg my pardon. Where y'all from...cunt?" Now, i suppose the punchline has something to do with the not-preposition, but what i don't get is why the Connecticut girl even considers that a sentence cannot end with a preposition? Is there any reason for stating that prepositions can't be on the end of a sentence? And if not, what is the punchline of this joke? If this joke's punchline is not pertaining to English language or if this is not a grammatical joke, i'm sorry and will remove the question. | Like many others, I commonly find myself ending a sentence with a preposition. Yes, it makes me cringe. I usually rewrite the sentence, but sometimes (in emails) I just live with it. To, with... you know who you are. Should I keep fighting myself on this one, or is it okay in some circumstances? |
Quite new to Blender. I'm using 2.75 and was working on this lamp (part of a Udemy course). I was using the Render Border tool (Ctrl+B) to constrain rendering to part of the model and somewhere in amongst cancelling/redrawing that and moving the camera around my file now only displays a minimal part of my model in both Object and Edit modes when using anything except Rendered Shading (see images). I got to that point where I'd pressed a bunch of keys and couldn't remember quite what I'd done, couldn't undo it etc. It looks like a bug to me tbh, but if anyone knows which shortcut I may have pressed to limit the viewport like this I'd appreciate it! If there is anyway to host the .blend file somewhere if anyone wanted to take a look, then please let me know. | When looking at my objects in 3d view I'm seeing a gray cone that seems to be hiding other objects. Can anyone help me turn this off and explain what it is please. Screenshots attached. |
I want to connect two laptops with a crossover Ethernet cable, in order to synchronize them with ntp. One laptop runs Windows 7, the other one Ubuntu. On Ubuntu, in order to assign a static IP address to an interface, I just do: sudo ifconfig eth0 10.0.0.100 netmask 255.255.255.0 Is there a similar way for Windows, from the cmd? | I need fixed IP in three wireless networks I log in frequently. It is a pain to set those IP and gateway everytime I change networks. I am willing to write a script to change my IP and gateway between those 3 fixed IPs and a choice to make it get IP automatically (when I´m in another network). A plus feature to my script would be if it could discover the wireless network I am logged in and decide the IP automatically. Is it even possible? Thanks. |
I have a localhost webapp (development) that requires a login to use and I would want to implement Visual Testing which for me means having a tool taking screenshots when I want and, as a plus, do the image diff. The tool must be free and a big plus is if it's very easy to implement: I don't mind coding the test cases if needed but any kind of GUI would be a major plus. I also don't mind the tool requires to be installed on a server or anything like that. It's not important to test on different resolutions/browsers, this is more about keeping 'stability' and knowing which pages changing than making sure everything is working OK visually. Something that uses Chrome to render the page is also nice. | For testing the visual appearance of a website the use of tools like selenium (functional surface test) is not sufficient because it doesn´t check the visual appearance and/or the CSS-Code directly. Different approaches are possible Defining style guides Syntax checking of CSS and HTML DOM comparison Screenshot comparison How do you check the visual appearance of websites from a web-application? I implemented a screenshot comparison tool in Java. Screenshots are generated by a framework based on selenium. I started with pixel by pixel comparison. Actually I split the screenshot into different parts (maybe 10x10 rectangles) and compare the histograms of corresponding parts. For the future I want to determine relevant parts (regions of interest) automatically. Maybe someone has ideas how to do that. |
When starting Minecraft, it immediately crashes with this crash log: [Launcher] Starting Minecraft 1.12.2... [Launcher] Launching in: C:\Users\Jaideep\AppData\Roaming\.minecraft [Launcher] Processing post-launch actions. Assist launch: true ==================================================================== > [19:32:19] [Client thread/INFO]: Setting user: Jaideepndhruv > [19:32:29] [Client thread/INFO]: LWJGL Version: 2.9.4 Here I am! [VersionManager] Refreshing versions locally... [VersionManager] Versions has been refreshed (94 ms) [TlauncherManager] before clearLibrary [TlauncherManager] after clearLibrary [Launcher] Launcher exited. [Launcher] Minecraft closed with exit code: -1073741571 What can I do to make Minecraft work? | Similar to on the bugs in Minecraft, I would like a complete list of what error codes exist in Minecraft and how they occur, as well as how they can be resolved. |
If I use an an align environment within the a beamer block, the \abovedisplayskip is ignored. How can I force that setting? My MWE is \documentclass[t]{beamer} \usecolortheme{rose} \usepackage{amsmath} \begin{document} \abovedisplayskip=0pt \begin{frame} \begin{block}{Some Block} \begin{align} %does not have 0pt abovedisplayskip e^x &= \sum_{k=1}^\infty \frac{x^k}{k!} \end{align} \end{block} \begin{block}{Some other Block} text \begin{align} %abovedisplayskip works after text line e &= \lim_{n\to\infty} \left(1+\frac1n\right)^n \end{align} \end{block} \end{frame} \end{document} | I want to reduce the white space (above and below) when I insert an equation environment in a beamer block. \documentclass{beamer} \usetheme{Antibes} \usepackage{amsmath} \begin{document} \begin{frame} \begin{block}{Separation of variables} \setlength\abovedisplayskip{0pt} \begin{equation} 1 + 2 = 3 \end{equation} \end{block} \end{frame} \end{document} I searched the web of course but the solutions I found do not seem to work (like \setlength\abovedisplayskip{0pt}). What I found and should have worked: |
I am trying to delete this folder, C:\Windows\System32\catroot. I am using the application, LockHunter and it is telling me that it is being used by the system and the svchost.exe and it is preventing me from deleting it. How do I delete this folder? Thank you for your help and support! | Sometimes when I'm working in Windows I'll get this prompt when I try to delete a directory: Folder In Use The action can't be completed because the folder is open in another program Close the folder and try again. However, the folder isn't "in use" at all, and I don't have it open. So how can I delete it short of rebooting? |
my tex: \documentclass[12pt,a4paper]{report} \usepackage{setspace} \onehalfspacing \usepackage[ left=3cm, headheight=33pt, top=3cm, right=2cm, bottom=2cm, includehead, includefoot, bindingoffset=5mm ]{geometry} \usepackage[utf8]{inputenc} \usepackage[bahasai]{babel} % <---- main language last \usepackage{csquotes} \usepackage{biblatex} \addbibresource{sample.bib} \usepackage{lipsum} \usepackage{titlesec} \titleformat{\section} {\normalfont\fontsize{14}{15}\bfseries} {\thesection} {1em} {} \usepackage{graphicx} %\usepackage[colorinlistoftodos]{todonotes} %\usepackage{showframe} \usepackage[linktocpage]{hyperref} \hypersetup{ colorlinks, citecolor=black, filecolor=black, linkcolor=black, urlcolor=black } \makeatletter \def\@makechapterhead#1{% %%%%\vspace*{50\p@}% %%% removed! {\parindent \z@ \centering \normalfont \ifnum \c@secnumdepth >\m@ne \Large\bfseries \MakeUppercase{\@chapapp}\space \thechapter % <--- uppercase \par\nobreak \vskip 0\p@ \fi \interlinepenalty\@M \LARGE \bfseries #1\par\nobreak \vskip 30\p@ }} \def\@makeschapterhead#1{% %%%%%\vspace*{50\p@}% %%% removed! {\parindent \z@ \centering \normalfont \interlinepenalty\@M \LARGE \bfseries #1\par\nobreak \vskip 30\p@ }} \makeatother \usepackage{fancyhdr} \pagestyle{fancy} \rhead{\includegraphics[height=1cm]{LOGO_PLN.png}} \lhead{\includegraphics[height=1cm]{LOGO_IP1.png}} \renewcommand{\headrulewidth}{1.5pt} \begin{document} \pagenumbering{Alph} \begin{titlepage} \begin{center} \includegraphics[width=5cm]{LOGO_IP2.PNG}\\[0.25cm] \textbf{PT. INDONESIA POWER UJP ADIPALA}\\[1.75cm] \textbf{PROJECT ASSIGNMENT \\[4cm]} \textbf{RETROFIT PLC TWIDO KE PLC S7-200}\\[4cm] \textbf{Diajukan Oleh:}\\ \textbf{Abdul Qoyyim}\\ \textbf{SIC-257}\\[3.5cm] \textbf{PROGRAM ON THE JOB TRAINING}\\ \textbf{DIKLAT PRAJABATAN ANGKATAN 23}\\ \textbf{TAHUN 2017} \end{center} \end{titlepage} \pagenumbering{roman} \chapter*{LEMBAR PENGESAHAN} \thispagestyle{fancy} \lipsum[3] \chapter*{ABSTRAK} \thispagestyle{fancy} \lipsum[5] \chapter*{KATA PENGANTAR} \thispagestyle{fancy} \lipsum[6] \tableofcontents \thispagestyle{fancy} \listoffigures \thispagestyle{fancy} \listoftables \thispagestyle{fancy} \pagebreak \pagenumbering{arabic} \chapter{PENDAHULUAN} \thispagestyle{fancy} \lipsum[1] \section{Latar Belakang} \lipsum[2-3] \section{Perumusan Masalah} \lipsum[3] \section{Maksud dan Tujuan Project Assignment} \lipsum[4] \section{Ruang Lingkup} \lipsum[5] \section{Metodologi} \lipsum[6] \chapter{LANDASAN TEORI} \thispagestyle{fancy} \lipsum[7] \begin{figure}[h] \centering \includegraphics[width=0.25\textwidth]{LOGO_IP3.png} \caption{a nice plot} \label{fig:mesh1} \end{figure} As you can see in the gambars \ref{fig:mesh1}, the function grows near 0. Alsos, in the page \cite{einstein} \pageref{fig:mesh1} is the same example. \lipsum[1-3] \chapter{PEMBAHASAN PROJECT ASSIGNMENT} \thispagestyle{fancy} \lipsum[8] \chapter{MANFAAT PROJECT ASSIGNMENT} \thispagestyle{fancy} \lipsum[9] \section{Manfaat Finansial} \lipsum[10] \section{Manfaat Non Finansial} \lipsum[11] \chapter{KESIMPULAN DAN SARAN} \thispagestyle{fancy} \lipsum[12] \section{Kesimpulan} \lipsum[13-14] \section{Saran} \lipsum[14] \printbibliography[heading=bibintoc,title=Referensi] \end{document} | From time to time, I need to typeset Welsh. Sometimes, I need to typeset citations and bibliographies in Welsh. I think that last time I did this, I may still have been using BibTeX although I am honestly not sure. In any case, my entire work-flow now uses biber and biblatex... I found on changing the names of things, including the names of things used by biblatex. However, that cannot deal with the case of an unsupported language. Suppose that I want to typeset a document in Welsh: \documentclass[a4paper,welsh]{article} \usepackage{babel} \usepackage[utf8]{inputenc}% welsh needs utf8x but biblatex doesn't like it \usepackage[T1]{fontenc}% not great for Welsh but the best pdfTeX can do \usepackage{csquotes}% doesn't like Welsh though biblatex likes csquotes on account of babel... \usepackage[backend=biber]{biblatex} \bibliography{biblatex-examples} \title{Fy Nogfen} \author{Rhywun} \begin{document} \maketitle \tableofcontents \section{Cyntaf} \autocite{westfahl:space} \printbibliography \end{document} There are multiple problems in such a case. (One is that I need utf8x but can't use it on account of biblatex. Another is that I need utf8x at all. Another is that biblatex likes csquotes but csquotes doesn't do Welsh. But these are irrelevant to this question.) The output is as follows: Note that the use of the English citation is just so this is easy to reproduce. Obviously, the content of the reference might well be in Welsh. (Though it might be in English, too.) As can be seen, while elements of the document controlled by babel are handled correctly, those under the control of biblatex are not. However, I cannot simply modify the solution offered by lockstep for changing strings to customised English variants. That is, I can't just use a Welsh version of \DefineBibliographyStrings{english}{% bibliography = {Works Cited}, references = {Works Cited}, } because biblatex has never heard of it. What is the most appropriate way to configure biblatex for use with an unsupported language? |
Seeing as midichlorians are found in all life in varying levels, it's conceivable that a Sith Lord could harness their resources to discover a way to do this and subsequently add it to their bodies. If midichlorian count is important as a ratio of power of the Force, then it stands to reason the higher the count the better and thus makes the perfect incentive for a Sith Lord to harvest and incorporate midichlorians into their own body. But why haven't they? Or why haven't we heard of this? | The more questions about the Force I read in here, the more Midi-chlorian count is used as a reference. As I understood, Midi-chlorians are the measurement for the Force power level of one user. As I remember, they are microscopic life-forms in the red blood cells that talk spiritually to the user. This then leads me to a question, if it is possible to give someone else an infuse of blood with Midi-chlorians. That then leads me to another questions. What happens if you use Force blood to rescue someone without it? Do already-infused get stronger? As I only know the films and very few other cannon material (games), I have to ask you: Are Midi-chlorians able to be infused to another body and do they have an impact to that another being? |
I have data in Sheet1 that I wish to import into Sheet2 with ImportRange. However, when the cell in Sheet1 is marked with a "strikeout" I want it to also import as a strike-out cell in Sheet2. Is this possible? | Is it possible to reference a cell in Google Sheets so that cell where it gets displayed also displays it using the same text and cell colour formatting? =A1 Will only reference cell's value. But if that particular cell has red background and white text I'd like that to be copied as well. I'm leaning toward existing formula solutions rather than scripts. If applicable of course. |
I am trying to mimic the style of a certain Journal, where some figures can be formatted to be of 1.x column width (say x=0.25 or x=0.5). Here is an example: Is there any package or way to do so? In my search, I have unfortunately not been able to find any tutorials on how to do so. Ideally, I would like a flexible method that lets me have 1.x column width figures, where I can specify x (although a baked-in static x choice would work too). | I need to insert a figure into a two column document such that the figure partially spans both columns, and the text wraps around it. It seems wrapfig does not work for this in two column, pullquote does not seem to either be exactly what I need. I've tried using minipage with no luck. I tried to post an example of what I need to accomplish but since I am new this forum I cannot. I'd be happy to send an image if this helps. Any suggestions would be fantastically helpful! |
I've got a WD EasyStore 1TB external hard drive that won't show up in disk utility at all. I've tried multiple MacBooks and on my raspberry pi. The ONLY thing I can get to recognize the hard drive itself are the WD Drive Utilities (yuck), but when I try to erase it from there the application crashes. I have looked for a fsck_hfs or fsck_exfat process running to see if the machine is trying to repair the disk before it runs it at all. Nothing. When I try to reboot my MacBook with the drive connected to it, it stays stalled on the apple logo for as long as I'll let it. I can see that it is recognized as a USB connection in System Information, but it is not recognized as storage at all. Help, please!!! | I am on a MacBook Pro 13 running latest Sierra. I have an external Seagate solid state hard drive that was working and out of the blue stopped working. The only thing on it was my Adobe Lightroom images/videos. Not the LR DB files. I'm sure you have all heard this woe before, so I won't dwell on that. And yes, I back up to the cloud. AWS S3 specifically. Though I am traveling South East Asia for the last year, and staying in cheap hostels. So good internet is hard to come by sometimes. I can't back it up after every export. While most of it is backed up, there is some that is not. Moving on. The symptoms seems to change every time I plug it in. The first sign was it ejected on it's own. I plugged it in again, and it wouldn't mount. Disk Utility recognized it, so did the command line diskutil list but it wouldn't mount. I rebooted and it worked for a second. Then I could only get to it from the command line. Then trying to frantically back up to my local what was not backed up to the cloud, it all failed. Basically just a cp -R [directory] [local-directory] command. After some more frantic unplugging and re-plugging plus some command line manual mounts, I finally got it to where the Disk Utility would be able to run first aid on it. It failed. I don't recall the error. So I put it in a freezer. After a few hours I tried again. It is not any better. It still will not mount. Now Disk Utility sees it, but with no partition. I can't even give me information about how much space is used on it. I have also tried it from a Windows machine. It did not mount. I have tried other cables. No success. As well as tried my other USB port. I also have another working external hard drive exactly like the one giving me issues. It works on all cables and USB ports. I do have Docker running with a Ubuntu container, I'm trying to think of a way to see if I can try to get to the USB from there. I also have a USB that I have thought about running a live Ubuntu on there to see if I can mount and retrieve the data or fix the HDD that way. But if it will not mount, I doubt these will work. Can anyone else think of any other tricks I can try myself to see if I can repair this or at least retrieve the data without paying for a service or software? If not, those suggestions are also welcome. Update I made the mistake in original post that it was a Solid State Drive. This is my mistake, it is actually a spinning disk hard drive. I bought them long ago and have been traveling with them for so long I just forgot. Question is updated to reflect this. Now diskutil list does not show it at all. The Disk Utility app also does not see it. Based on suggestion from @Allen I seeked out the USB to SATA cable. I did not quite find it, as my options are extremely limited where I am at. Though a local expat on a facebook group was able to help me with a empty 2.5 casing that I was able to extract the drive from original casing and put it in his blank case. It now mounts. Though it has the "click of death" sound to it. And data is not really reachable. While I can ls the directories and Adobe Lightroom does not have the exclamation mark when it can not reach the actual external files. Right clicking on the images and clicking on "Show in Finder" or any other variation of trying to get to the files through Finder or terminal, I have no success. It usually hangs and I get the spinning wheel. Since Adobe Lightroom imports these images into directories named by date, I am going to send the drive off to a data recovery service and ask to recover just unbacked up directories i.e. dates. Next time I will make harder efforts to backup and probably get an actual SSD. I think this can be closed, due to my low reputation points I can not close this myself. |
This is a bit of a strange issue for me and I wasn't sure how to properly title the question. I have the follow MWE which simply generates a list of coordinate points (x,t) and performs some check to see if they lie on a user-prescribed boundary. In particular, if x[i] == 1.0 and t[i] != 0.0 then the program should print a statement stating so. I can't seem to figure out why the if conditional is never entered here. I have printed out the pairs of values x[i] and t[i] to verify that there are indeed pairs satisfying the conditional... #Load Modules import numpy as np import math, random from pylab import meshgrid # Create the arrays x and t on an evenly spaced cartesian grid N = 10 xa = -1.0; xb = 1.0; ta = 0.0; tb = 0.4; xin = np.arange(xa, xb+0.00001, (xb-xa)/N).reshape((N+1,1)) tin = np.arange(ta, tb+0.00001, (tb-ta)/N).reshape((N+1,1)) X_tmp,T_tmp = meshgrid(xin,tin) x = np.reshape(X_tmp,((N+1)**2,1)) t = np.reshape(T_tmp,((N+1)**2,1)) # create boundary flags for i in range(0,(N+1)**2): if (x[i] == xb and t[i] != ta): print("We are on the right-side boundary") | Consider the following code: 0.1 + 0.2 == 0.3 -> false 0.1 + 0.2 -> 0.30000000000000004 Why do these inaccuracies happen? |
My markup has the following structure: <Header/> <main style={{display: 'flex'}}> <div style={{flexGrow: 1}} id='one'>Left Panel</div> <div style={{flexGrow: 5}} id='two'>Main Content</div> </main> Do not bother about <Header />. It is a React component that lies at the top of the page and has a certain height (not fixed). What I want is div one to take the entire height of the available viewport; that means 100vh minus the height of the header that we do not know. How is that possible? | I am working on a web application where I want the content to fill the height of the entire screen. The page has a header, which contains a logo, and account information. This could be an arbitrary height. I want the content div to fill the rest of the page to the bottom. I have a header div and a content div. At the moment I am using a table for the layout like so: CSS and HTML #page { height: 100%; width: 100% } #tdcontent { height: 100%; } #content { overflow: auto; /* or overflow: hidden; */ } <table id="page"> <tr> <td id="tdheader"> <div id="header">...</div> </td> </tr> <tr> <td id="tdcontent"> <div id="content">...</div> </td> </tr> </table> The entire height of the page is filled, and no scrolling is required. For anything inside the content div, setting top: 0; will put it right underneath the header. Sometimes the content will be a real table, with its height set to 100%. Putting header inside content will not allow this to work. Is there a way to achieve the same effect without using the table? Update: Elements inside the content div will have heights set to percentages as well. So something at 100% inside the div will fill it to the bottom. As will two elements at 50%. Update 2: For instance, if the header takes up 20% of the screen's height, a table specified at 50% inside #content would take up 40% of the screen space. So far, wrapping the entire thing in a table is the only thing that works. |
Is there a way to not only protocol/log the console inputs (like the history), but also the console output by default (without the constant usage of pipes)? | I do not know if this is even possible or not, but in an attempt to keep track of many changes I am about to make to my system I want to track all input I type and all output from a terminal I'm working with to a file. I've been messing around trying to do this and here is what I have so far: bash > /tmp/output.txt This has some quasi success. I tested this with something simple: sudo apt-get update && sudo apt-get upgrade which dumped the normal output to the file, but not what I typed in. Additionally I'd like to be able to see the output as well as have it stream to my output file, just for readability. (This can be worked around with a second terminal running tail -f, but it'd be nice to have it in one place). |
So, the way I've always played you can't add a draw 2 on a draw 4 but I've seen plenty of other people do it. So I'm wondering if you can or can't? | Is it within the UNO rules to put a Wild Draw 4 card on top of a Draw 2 card, as it is a 'higher' card? We've ALWAYS played that you can, but my new friend is adamant you can't. |
Let $A$ be an $n \times n$ matrix. If $A$ is invertible, then $|A| \neq 0$. How I can justifying the answer? | Whenever I needed to find the inverse of a matrix, I was told to check if its determinant is not zero. However, once I directly applied the Gauss-Jordan's method for finding the inverse of matrix whose determinant was zero. The inverse matrix that I got looked pretty normal like any other (if there wasn't a mistake). I want to know how does the determinant of the matrix is related to inverse of matrix or why is that if determinant is zero then inverse doesn't exist? What exactly is inverse? |
I (think I) know how to pluralize an indirect quote, e.g., Their survey answers were limited to yeses and nos. But how do I pluralize a direct quote ending in a punctuation mark? Am I even allowed to retain the punctuation mark for emphasis? In other words, would the correct form(s) be: There was no shortage of "How do you do?"s and "Let's do lunch!"es at the networking event. There was no shortage of "How do you do"s and "Let's do lunch"es at the networking event. There was no shortage of how-do-you-dos and let's-do-lunches at the networking event. [something else altogether] Does the number of correct forms change when I elect to italicize quotes, rather than demarcate them with quotation marks? A/N: I was trying to keep my example short, but I do realize that "how-do-you-do" is already an . Hyphenation seems unwieldy, however, if the quote were longer. | Is there a way to pluralize a quotation? E.g., He was greeted with a chorus of “Hello”s. or Her daring earned “Ooh”s & “Ahh”s from around the room. With actual dictionary words (“Hello” in the first example), simple plurals might do, without quotes: “He was greeted with a chorus of hellos.” With ad hoc onomatopoeic words like “ooh” & “ahh”, though, can I pluralize them without confusing the reader? Is italicizing part of the word acceptable: “Her daring earned oohs & ahhs from around the room”? |
I have object which is moving and i want to include its path in render. Is there a way? I trired "Motion path" option, but this doesnt show in render. Is there a way to for example plot trajectory if i have all the points or is there some ad on? | Once you have an animated object using typical key-framing (other methods such as physics, driver or NLA apply too). It could be useful to apply the motion to a path: to adjust the evaluation time edit curve points points may be easier have many objects move along the same path. ability to follow the path. Is there a way to do this? Note that rotation and scale won't be taken into account. |
I hope someone here can help me out. So, I'm switching from zbrush to blender because of licensing issues and I'm having a bit of a problem with simple sculpting work. I already increased the resolution of my model with the multi res modifier and tried different types of dynamic topology modes but I always get weird artifacts with most brushes ( see image below) Does anyone know what the problem is and what I can do to fix it? Thanks in advance! | When I try to sculpt with dyntopo on a sword it creates really weird results while it works just fine on other meshes. Any idea what causes this? |
I'm writing a program in C to add random numbers to an array. The size of the array is given (say n = 250) and using rand(), I'm generating these numbers (range is 1 to 100). int main() { int n = 250; int array[n]; for (int i = 0; i < n; i++) { srand(time(NULL)); int r = rand()%100 + 1; array[i] = r; } printf("Output Size: %lu\n", sizeof(array)); return 0; } When I run the code, the result is- Output Size: 1000 Expected result is 250. What am I doing wrong? | How do I determine the size of my array in C? That is, the number of elements the array can hold? |
Every time I steal something the guards say: "You have committed murder and conspiracy against the city of Markarth". How do I fix this? | Is it possible to kill all of the guards in a town? Ideally, I'd like to do this secretly so the entire town doesn't see my deeds and put a bounty on my head. Edit: I was questing in Markarth and was told by a guard to back off and stop being nosy. I didn't and when I went to the Shrine of Talos I was set upon by a bunch of guards. Now I have a huge bounty and I had to sneak/kill my way out of the city. Every time I killed a group of guards the bounty was reduced by $1000, but I still have a $30,000 bounty. I haven't even been through 1/3 of the city yet and know there has to be a lot of quests, so what do I do? The only solution seems to kill every single guard (and inhabitant). |
I am experimenting with specialized destructors. This code is perfectly valid and compiles just fine: #include <iostream> using namespace std; template <typename T> class Cat { public: ~Cat(); }; template <typename T> Cat<T>::~Cat() { std::cout << "T" << std::endl; } template <> Cat<int>::~Cat() { std::cout << "int" << std::endl; } int main() { Cat<int> c1; Cat<float> c2; return 0; } However if I put the class and the destructors in a separate file "Cat.h" and do #include "Cat.h" in Main.cpp, I'm getting a linker error: LNK2005 "public: __thiscall Cat<int>::~Cat<int>(void)" (??1?$Cat@H@@QAE@XZ) already defined in Cat.obj. Why? | I have some template code that I would prefer to have stored in a CPP file instead of inline in the header. I know this can be done as long as you know which template types will be used. For example: .h file class foo { public: template <typename T> void do(const T& t); }; .cpp file template <typename T> void foo::do(const T& t) { // Do something with t } template void foo::do<int>(const int&); template void foo::do<std::string>(const std::string&); Note the last two lines - the foo::do template function is only used with ints and std::strings, so those definitions mean the app will link. My question is - is this a nasty hack or will this work with other compilers/linkers? I am only using this code with VS2008 at the moment but will be wanting to port to other environments. |
Suppose I know a result that the set of finite sets in $\mathbb{N}$ is countable. Is there a very quick way to show that the set of finite sets in any $X$ countable is countable? Idea...two sets have same cardinality if there is a bijection, we biject set of finite sets, bijection preserves cardinality. End of proof. | I am looking for a beautiful way of showing the following basic result in elementary set theory: If $A$ is a countable set then the set of finite subsets of $A$ is countable. I proved it as follows but my proof is somewhat fugly so I was wondering if there is a neat way of showing it: Let $|A| \le \aleph_0$. If $A$ is finite then $P(A)$ is finite and hence countable. If $|A| = \aleph_0$ then there is a bijection $A \to \omega$ so that we may assume that we are talking about finite subsets of $\omega$ from now on. Define a map $\varphi: [A]^{<\aleph_0} \to (0,1) \cap \mathbb Q$ as $B \mapsto \sum_{n \in \omega} \frac{\chi_B (n)}{2^n}$. Then $\varphi$ is injective hence the claim follows. (The proof of which is what is the core-fugly part of the proof and I omit it.). |
I don't understand the reasoning behind it. I was trying to figure it out with the chain rule in the case of $e^x$, but the I would get $(X(e)^x-1)(e^x)$ and I can't find the reasoning by my own | $$\frac{d}{dx} e^x=e^x$$ Please explain simply as I haven't studied the first principle of differentiation yet, but I know the basics of differentiation. |
We say that $f:\mathbb{R}\to\mathbb{R}$ has a local minimum at every point, if for any point $x_0$ we can find an open interval containing $x_0$ such that $f(x)\ge f(x_0)$ for every point in the interval. Suppose $f$ is any function $\mathbb{R}\to\mathbb{R}$ satisfying this condition (so, in particular, it is not necessarily continuous). It does not follow that $f$ is constant. For example, take $f$ to be 0 on the integers and 1 elsewhere. So the question is prove that $f$ is constant except at (at most) countably many points, or find a counter-example. | What are the functions $f:\mathbb R\to\mathbb R$ such that every point is a local maximum? Certainly, $f(x)=c$ works for every constant. So does $\lfloor x\rfloor$, as does $I_{\{0\}}(x)=\begin{cases}1&x=0\\0&x\ne0\end{cases}$. Another example is the oddly beautiful $e^{-\lfloor1/\lvert x\rvert\rfloor^{-2}}$. Question is, are step functions such as these the only ones? Are there any examples where every point is a strict local maximum? (Thomae's function is a near-miss, since the condition doesn't hold on irrational points. Although, most points are irrational, so I guess the term "near-miss" doesn't quite fit.) EDIT: My definition of step-function is the sum of countably many indicator functions of intervals, $\sum_{n=0}^\infty a_nI_{A_n}(x)$. If it were uncountable, any function would be step, as $\{\alpha\}$ is an interval ($[\alpha,\alpha]$). This arose when I was thinking about the topological space with basis $\{(-\infty,a]:a\in\mathbb R\}$. If you call that space $X$, then the continuous functions $f:\mathbb R\to X$ are precisely these. I don't have a formal proof but I'm pretty sure (and this would belong in a different question anyway). Contrast with: |
I have a variable named title which is having the value "Javascript,XML,XHTML,CSS,Ajax". I need to compare in an if statement if the title equals to the above value some code needs to be run. I have used if (title == "Javascript,XML,XHTML,CSS,Ajax"){ } else if (title == " ") { } else { } When the title is null, the code goes to the second else part and gets the correct result. But when the title is equal to Javascript,XML,XHTML,CSS,Ajax the code goes to the last else part instead of going to the if part. What mistake have I done here? I have checked the upper lower case and also spelling along with the delimiter comma the string is same just as in the variable title. Then why do I not get the correct answer. | 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? |
Please proof that $A\cap B=A\setminus(A\setminus B)$ this really gave me sleepless night. I tried using the set intersection properties but I still got confused. | How does one show that $A\cap B = A\setminus (A\setminus B)$? My thinking is that if $x\in A\setminus (A\setminus B)$ then this means that $x\in A$ and $x\notin A\setminus B$, which means that $x\in A$ and ($x\notin A$ and $x\in B$), but I don't see why the expression in parentheses should simplify to just $x\in B$. Any insight would be helpful. Maybe $(x\in A^c$ and $x\in B)$, i.e, $x\in A^c\cap B$ is a possible simplification of the expression in parentheses, but still don't see why this simplifies to just $x\in B$. |
Ok, so this is a weird question as it makes my mouse next to useless while this is active. I want to be able to click my mouse and it in turn think will I'm pressing a key on my keyboard instead of clicking the mouse. Is this even possible? I want to use it so I can play a game called Rogue Legacy (a platformer). Because currently there is no way to bind your mouse to attack, which is really annoying to me. This is not a duplicate, this is why: I'm trying to bind my left click on my mouse to press the F key on my keyboard instead of registering it as a left click from the mouse. | I'm trying to map/bind my mouse button 4 and button 5 to behave as kayboard num pad 1 and 2, does exist some way to do that? Maybe with some specific software? |
The title says it all, really. I'm confronted with this problem from my topology course, and I have made no progress. I'm not sure if I'm supposed to solve it with the "standard" topology on R or something else, but I think its true even with the "standard" topology- I just can't find such a function. I would add that this is an introductory course in topology and I don't know most advanced notions. | What is an example of an open map $(0,1) \to \mathbb{R}$ which is not continuous? Is it even possible for one to exist? What about in higher dimensions? The simplest example I've been able to think of is the map $e^{1/z}$ from $\mathbb{C}$ to $\mathbb{C}$ (filled in to be $0$ at $0$). There must be a simpler example, using the usual Euclidean topology, right? |
If we have two real numbers $u,v\ge 0$ with the continued fractions $$u=[0,a_1,a_2,a_3,\cdots]$$ and $$v=[0,b_1,b_2,b_3,\cdots]$$ can we calculate the continued fractions of $u+v,u-v,uv,\frac{u}{v}$ only using the continued fraction representations of $u$ and $v$ ? | I'm interested in the arithmmetic of continued fractions and specially in multiplication. Consider $$ f(x)=\cfrac{f_{0}(x)}{1-\cfrac{f_{1}(x)}{1+f_{1}(x)-\cfrac{f_{2}(x)}{1+f_{2}(x)-\cfrac{f_{3}(x)}{1+f_{3}(x)-\cdots}}}} $$ and $$ g(x)=\cfrac{g_{0}(x)}{1-\cfrac{g_{1}(x)}{1+g_{1}(x)-\cfrac{g_{2}(x)}{1+g_{2}(x)-\cfrac{g_{3}(x)}{1+g_{3}(x)-\cdots}}}} $$ Are there arithmetic rules (algorithms) for the multiplication of continued fractions? Specifically, is it possible to obtain a continued fraction $h(x)=f(x)\cdot g(x)$ where $$ h(x)=\cfrac{h_{0}(x)}{1-\cfrac{h_{1}(x)}{1+h_{1}(x)-\cfrac{h_{2}(x)}{1+h_{2}(x)-\cfrac{h_{3}(x)}{1+h_{3}(x)-\cdots}}}} $$ I've found , but I'd like more. Does anyone here knows of papers, algorithms, etc? Thanks. Update 1: Another . |
I was wondering What the command ./ exactly does example:./ts3client_runscript.sh start Thanks for help. | I've been told to run this: ./yiic message ./app/messages/config.php But I don't understand the ./ meaning, can anyone clarify please. Note: Believe me, we can't google that. I've tried: ./ meaning ./ ubuntu It was the same as nothing. :( |
I'm supposed to make a function that returns a new String that looks like base appended with suffix, but if the base already end s with the suffix it returns the base. For example: if base is lightning and suffix is bug, then it returns lightening bug But if base is lightning bug and suffix is bug it also returns lightning bug. I'm actually not sure how to start this, so I just need help with the first step, then I'll try to build off of it. Also I cannot use arrays, so >it's supposed to be really basic. so far I have: public static String appendIfMissing(String base, String suffix) { if(base != suffix) { return base + suffix; } return base; } | 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'm coming from Canada and will be riding in the London-Edinburgh-London randonneuring ride which finishes in Loughton. The London Underground info. shows that I can take my bike on the Central line and shows it until Leyton. Does this mean I have to get off at Leyton or can I continue on to Bank station? Do the allowable stations mean that's where I'm allowed to board or can I continue? Thanks - Terry | Can I take a bike on the Tube (underground) in London, if so how much does it cost? |
I'd like to prove this statement: Let $X$ a normed space. If $X$ has a linearly independent subset of cardinal $n$, then so does $X'$. I know that I have to use the Hahn-Banach theorem to prove the existence of functionals in $X'$ that hold the above mentioned property but I'm not sure how. Any suggestions are welcome. Thanks in advance. | Given an arbitrary infinite dimensional Banach space $X$, can we deduce that it's dimension $\dim(X)$ (the cardinality of one of its Hamel bases) is less or equal of the dimension $\dim(X^{\ast})$ of its dual space (the space of all continuous linear functionals $f:X\to\mathbb{R}$)? |
I've got a rather unusual question. I've seen two variants of passing arguments to malloc. Let's say we've got: int *arr = (int *) malloc(sizex * sizeof(*arr)); Some people say that using sizeof(*arr) is bad and you should use sizeof(int) (in this example) instead. Could you explain what's the difference and what's better to use? | Recently saw someone commending another user on their use of sizeof var instead of sizeof(type). I always thought that was just a style choice. Is there any significant difference? As an example, the lines with f and ff were considered better than the lines with g and gg: typedef struct _foo {} foo; foo *f = malloc(count * sizeof f); foo *g = malloc(sizeof(foo) * count); foo **ff = malloc(count * sizeof *ff); foo **gg = malloc(sizeof(foo*) * count); In my opinion, the first set is just a matter of style. But in the second pair of lines, the extra second * can easily be confused for a multiplication. |
In Inception, why didn't Cobb just spin the totem in the real world to show Mal that she is finally back to reality so she wouldn't have killed herself? | In Inception, it was told that the totem's concept was invented by Mal. Then why didn't Mal use her spinning top to find out if she is in a dream or not before jumping off the window? Is it the case that she didn't remember that she has a totem? |
$$\int_0^1\frac{1+x^4}{1+x^6}\,dx$$ Can anyone help me solve the question? I am struggling with this. | I'm trying to compute: $$\int_{0}^{1}\frac{x^4+1}{x^6+1}dx.$$ I tried to change $x^4$ into $t^2$ or $t$, but it didn't work for me. Any suggestions? Thanks! |
I have a following problem: when I plug-in my USB flash drive, it isn't shown in Windows Explorer or recognized by system at all. In device properties, it is shown as: USB MEMORY BAR There's no partitions on the drive, so I can't format it: DISKPART: Virtual Disk Service error: There is no media in the device. HP USB format tool: There is no media in the specified device. Any help will be greatly appreciated! Thank You! | I have a 32 GB USB stick. I was in Mac (VMWare) putting some stuff on. Then accidentally removed the drive. I put it back in, and wanted to format it. Using disk utility, I chose 1 partition, it automatically filled in 312 GB and I just clicked format or whatever. It didn't take long, then I could see the progress bar hanging at "Waiting for device to reconnect". Nothing happened for a while so I ejected it. Now comes the problem: In Disk Utility (Mac): No sign of the USB drive. In Paragon Partition Manager (Windows): No sign of the USB drive. In Disk Manager (Windows): I can see that it's there. But it says: Disk 1 Removable (D:) No Media. When I right click it, I can only assign drive letters to it. No way to format. In diskpart (Windows): diskpart list will show me the following: Disk 1, Status: No Media, Total Size: 0 B. When I eject the drive, the disk 1 will disappear. So I know that it's this drive. If I type clean, it will say that "There is no media in the device". In HDD Low Level Format Tool 4.25 (Windows): Doesn't detect it at all. In Device Manager (Windows): It is detected as USB Mass Storage Device. In Gparted (Linux): Doesn't detect it. In HP USB Disk Storage Format Tool 2.1.8 (Windows): It detects device as: "GENERIC USB Mass Storage 1.00 (0 MB) (D:)". When I press Start it gives me this error: "There is no media in the specified device" In BIOS: Detected In Spinrite (Live Boot): Doesn't detect it Any help is appreciated. |
I found the following statement in youtube lecture: Let $A\subset \mathbb{R}^n$ be open and convex and let $f:A\to\mathbb{R}^n$ be continuously differentiable vector field. Then $f$ is conservative iff the Jacobian of $f$ is symmetric on $A$. I couldn't find a citable reference for this (for $n\ne3$). Does someone have one? Update: I'm still looking for a citable reference. | I want to determine whether a certain n-dimensional, simply-connected vector field is conservative. I can very easily calculate its Jacobian in numerical form. In 3 dimensions, the problem is easy: the Jacobian is a 3x3 matrix, and the curl can be obtained from its elements: [jacobian[2,1] - jacobian[1,2], jacobian[0,2] - jacobian[2,0], jacobian[1,0] - jacobian[0,1]] A curl of zero would mean that the vector field is conservative. But what if my Jacobian has 100 elements? The curl is only defined for 3 dimensions, but is there a formula for some high-dimensional generalization? |
A classmate sent me this question: A high school student had the option to attend 5 AP classes. If we assume the probability of signing up for each class is constant, then the amount of AP courses a student would take is a random variable distributed as: X ~ Binomial(n=5, p). If we have a sample of 120 high school students denoted $X_1, ..., X_{120}$, what would be the maximum likelihood estimate of $p$? We have this formula from our notes: $L(p)=∏^n_{i=1}p^{x_i}(1−p)^{1−x_i}$. However, he suggested maximizing the function $p^{x}(1−p)^{n−x}$ [here $x = \sum \limits_{i=1}^n x_i$], with $n=5$. Then we simply obtain that the maximum likelihood estimate as $p=\frac{x}{5}$. I feel that either I or the problem is missing some key information. Is this correct? | Assuming I need to find the ML estimator for p, p being the chance of success in a Binomial experiment $Bin(N,p)$, I would expect my density function to be: $$ f(y) = {{N}\choose{y}} p^y(1-p)^{N-y} $$ And so my likelihood function should be: $$L(p) = \prod_i^n(f(y_i)) = \prod_i^n({{N}\choose{y_i}})p^{\sum_i^n y_i} (1-p)^{nN-\sum_i^n yi}$$ However, the last exponent, $nN-\sum yi$ seems to be wrong because when I derive the log likelihood and isolate $p$, I get $p = \frac{\sum_i^ny_i}{nN}$, while it should be $p = \frac{\sum_i^ny_i}{N}$. Indeed, when checking online, I find different exponents: they have $N-\sum yi$, for no obvious reason to me (last time I checked, $\sum_i^n(N-y_i) = nN-\sum y_i$ !) as well, but there they start from the likelihood function of a Bernoulli experiment. It makes sense that $\sum_i^n(1-y_i) = n-\sum y_i$, but what is more obscure to me is why they take the likelihood function of a Bernoulli while the problem is clearly about a Binomial. I am aware of the link between the two, but not enough to see why their likelihood functions seem to be substitutable to estimate p, especially since it doesn't give me the same result. |
Is there a way to definitively tell what application is attempting to open a file on startup (if it is not in the Startup folder)? For example, when I boot my PC, I see the following message: My first step was of course to check the Startup folder. Nothing there (checked hidden files, too). I've looked through MSCONFIG startup services and none of them are related to the filetype. I've run in Safe Mode and the file does not open, but that still doesn't tell me what is calling the file on startup. I can open up task manager while the "Windows can't open this file" window is open, but that still doesn't tell me which of the running programs has called it. I've even tried searching for the file in hopes of deleting it, but every search I've ran for it has turned up nothing. | I know that under Windows there are multiple ways to get an app to autostart but I can never remember what all of those ways are. Is there a single unified way to bring up a list of all programs which are set to run themselves at startup and let me disable those I don't want? I'd prefer something built into Windows. I have Windows 7 Starter. But a free / open source / shareware tool would also be acceptable. (This time the software I want to prevent from autostarting is: MSN Messenger, Y! Messenger, and Vodaphone Mobile Broadband, which starts whether the dongle is inserted or not. None of these three are in Windows's "Startup" folder.) |
If adding is the sum of two numbers, Subtraction is the removal of a number from another. Multiplication is $x$ lots of $y$. Division is splitting $x$ between $y$. Powers are multiplying a value by itself. What is a square root? To be clear, I'm asking what function a square root actually performs? I can't seem to come up with an answer without the concept of powers to refer to. For example; how would you go about solving the square root of $121$ without prior knowledge that $11^2$ is $121$? Is it as blind as testing every value up to or past an answer until we find a solution then doing bisection until we get a result? Edit: I think my question was still unclear, how could I perform a square root on a value without reverse engineering the question into a powers question. E.g. square root $123456$, you do not know if the root is whole or decimal. | Okay, I know this is very basic question. I learned 2 methods in school. But now, I forget one. Here is a simple method that I know. Find the prime divisors of the number Omit the half of numbers that have been appeared even times multiply the rest For example you want to find square root of 36. You find the divisors. They are 2x2x3x3. In step 2 they appeared as 2x3. That is 6. Problem is this method works when the square root is an integer number. It doesn't work for numbers that doesn't have integer square root. Like 38. So my question is how can I find the square root of any arbitrary number using pen and paper? |
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