today, we were taught the polynomial remainder theorem and to prove it, the following identity was written in the board by our teacher. $$f(x) = g(x)(x-A) + R ----------->(1)$$ Here, f(x) and g(x) are polynomials with f(x) being the dividend and (x-A) being the divisor. R is a constant with real value. (Please excuse my English for I have studied mathematics in my native language) However, since I have knowledge in simplifying fractions, I thought that the same could be written as below, $$f(x) / (x-A)  = g(x) + R / (x-A) -------->(2)$$ In this case, we can not define the identity at x=A. (Or divide the polynomial at x=A for that matter). However we get the correct results from the connection I have marked as (1) above. How is this possible? To further elaborate my question with a count example, we can do the following, $$(x^3 + 6x^2 + 11x + 6) / (x+4) = x^2+2x+3-6/(x+4) ------->(3)$$ We know that we can not divide the polynomial at x = -4 in the connection I have marked as (3). However, we can write it as, $$(x^3 + 6x^2 + 11x + 6) = (x^2+2x+3-6)(x+4) - 6 -------->(4)$$ and then find the remainder by substituting x = -4 Can someone kindly explain to me how come this is possible?

This may be an incredibly stupid question, but why does partial fraction decomposition avoid division by zero?  Let me give an example:  $$\frac{3x+2}{x(x+1)}=\frac{A}{x}+\frac{B}{x+1}$$  Multiplying both sides by $x(x+1)$ we have:  $$3x+2=A(x+1)+Bx$$  when $x \neq -1$ and $x \neq 0$.  What is traditionally done here is $x$ is set to $-1$ and $0$ to reveal: $$-3+2=-B \implies 1=B$$ and  $$2=A$$  so we find that   $$\frac{3x+2}{x(x+1)}=\frac{2}{x}+\frac{1}{x+1}$$  Why can $x$ be set equal to the roots of the denominator (in this case, $0$ and $-1$) without creating a division by zero problem?


I own a Trek 3500 and am an avid biker... I bike on roads mostly, but sometimes on trails too.. Is there any information anyone could share that would assist me in adjusting air pressure in the Tire? or is it through and through fully filled up tires?   I feel that there might be a necessary modulation to better the ride experience on flat and smooth (road) and difficult (trails) tracks...

There's a question for mountain bike tyres but I can't seem to find anything on here for road bikes. At the moment I'm running at around 90psi. Is that too much? too little?  Also, am I more likely to get punctures running at higher pressure?  I seem to be getting a lot lately.


There exists various ways of destroying the data on a disk. Even simple wipes differ, some disk utilities give these options:   Format (does not actually wipe) Wipe 1 time with zero Wipe 1 time with random bits Wipe 7 times with zero / random bits Wipe 14 times with zero / random bits   Are they implying that data can be reserved somewhere else instead of writing to the disk (even cache exists the data should go to the disk I think), or the disk is totally not trustworthy by providing such options?

If you have a private data on a recent, normal hard drive - how many passes do you need to delete the data to make it unrecoverable?  Not in the sense, that a forensic team of 20 experts with a budget of 100 million euro or dollars and 10 years of time to restore a couple of bytes from a known address with 80% accuracy, but few people with a few 1000 €/$ budget, who wouldn't spend more than two weeks on the job, and who don't know where on the drive they are searching.   Linux/GNU shred says in the manual:     -n, --iterations=N           overwrite N times instead of the default (3)   but on the one hand I heard about an NSA suggestion to overwrite 27 times, and on the other hand professional data recovery firms could not recover data from a drive that was wiped just once.   Evidence, papers, proof?  Note: What this question is not:    It's not about bad sectors, where data might slip through It's not about old MFM/RLL-drives from the early 90ies  It's not about different tools It's not so much about the method (random numbers 0s, 0xFF and fancy patterns).  It's not about different techniques to wipe it securely (magnetic power, melting, filling with sand and turning).  It's not about special problems of flash drives


I am getting old and I need money. I bet many people do, but for some reason they prefer not to speak about it. Over 8 years at Stack Overflow I scored 11k rep and some badges.    There are not many answers there, as you may see below. It is roughly 64 rep per answer.    I like discovering things and going deeper into the matter. Like everybody else, I guess. But doing this is not fun anymore. Because companies need to do things fast. It is stressful, and I am not that stress resistant as every company wants. I also find it hard to work on problems that I don't find interesting, like doing the same bash script that was written 1000 times before by every and each developer who faced the same problem. This is my primary motivation in life - doing things properly once, to save time on scale, so that somebody else can spend this time better. This also makes me an awful employee, the one who misses deadlines and is not as effective as everybody else. Impostor is not a syndrome, it is a pressure, and I can not withstand it.  This is a long post for Stack Overflow. It is about getting some money for my reputation if anything that I did has any value to anyone. There are mining farms extracting crypto currency every N minutes, some of them burn energy, some do not. There are grants from Mozilla, USAID, Horizon 2020 but these are not accessible for someone who just digging in software problems. The competition for those is fierce, and it requires you to know beforehand what you will be doing.  I tried to help Gratipay as a platform that can be used to sustain ourselves, but it was shut down by FinCEN who over this years together with PayPal and other previous generation mafia invented rules that we can not compete with. I was involved in blockchain in the past year, but that didn't make secure. It is exciting to be there, but not so exciting to realize that I can not support myself and my family.  If I provided some value, is it possible to convert that value to something that will keep me alive? Or it doesn't matter for this site? If it was not me, then somebody else who has time and money would do this.  (sorry if I won't reply soon, bringing this up is exhausting, and I need to rest a bit)

Is it possible to convert my Stack Overflow reputation into dollars (or better in euro)? It would be nice to see a service which allows it (not to say it will encourage people to spend their time more productively).


Deleted questions only get soft-deleted. They are not shown anymore,   (but accessible to >10k-rep-users). Thus, they should be available   via the data dump.  How would you access, say, ?    It was alleged that this question is a duplicate of .   The duplicate-origin contains the information (in the question, it has no answers) that the data dump does not contain deleted questions, yet  offers deleted SO questions. Thus, it might be possible.

I like to use  to view usage stats for some of the sites, however deleted posts are not included on Data.SE and I think this skews the numbers quite a bit, particularly on sites with a lot of deletions. Would it be possible to include some limited data about deleted posts in Data.SE to make statistical queries more accurate? You could clear the non-public data fields of deleted posts, such as Posts.Title, Posts.Body, and Posts.OwnerUserId to address privacy concerns explained . You could even leave the PostId set to 0 since I know SE doesn't want to provide users with a way of searching deleted questions. The data I would mostly be interested in is CreationDate, LastActivityDate, PostHistory (date closed, date reopened, date deleted, etc), and the fact there was a deleted question in the first place. Up/Down votes, Score, Tags, and View/Answer/Favorite count would also be preferred. This would make the statistical queries accurate, while still removing the information not meant to be visible to the public.


I am a user of windows xp , now I am thinking of between switching or dual boot after I have finished the errors in my computer.  I would love dual boot but my harddisk will not be enough so if I delete windows xp will it affect my program and program files?

I need to install Ubuntu instead of Windows 7. Can you tell me the steps to do it? I don't want to install Ubuntu alongside Windows. Any precautions needed before installing Ubuntu? How do I install Ubuntu 11.10 without losing the current data in my laptop?


What do they mean? How should I use them? Which one is more appropriate to what context?  I was talking to a colleague of mine and we couldn't get to a consensus about what should we say when referring to drinks, for example:     A lemonade is made of lemons.   or     A lemonade is made with lemons.

What is the basic difference between "made of" and "made from." Both expressions are used in English. For instance, "This chair is made of wood," and "Cream is made from milk." Though the question is quite simple, I often confuse the two expressions. How do we differentiate them and what is the rule or logic behind their use?


I searched on Detextify, but I cannot find the symbol      | |     | |     | |     | | -----------   in LaTeX. There is \perp with only one vertical line. I look for a symbol which looks exactly like \perp, but has two vertical lines.  Thanks in advance.

I found from  that I could use the independence symbol:     \newcommand\independent{\protect\mathpalette{\protect\independenT}{\perp}} \def\independenT#1#2{\mathrel{\rlap{$#1#2$}\mkern2mu{#1#2}}}    I was wondering how this works. Can anybody explain? I don't know the commands mathpalette, rlap, and mkern2mu.


So far I have done the following work:  class Stamp{  public:     virtual std::string GetStampName() const { return "undefined"; } };   class FooStamp : public Stamp {  public:     std::string GetStampName() const override { return "foo-stamp"; } };   I use it like this:  FooStamp fooStamp; std::cout << "foo-stamp:" << fooStamp.GetStampName() << std::endl;  const Stamp stamp = fooStamp; std::cout << "stamp:" << stamp.GetStampName() << std::endl;   The actual output is as follows：  foo-stamp:foo-stamp stamp:undefined     // expected: foo-stamp   Types converted to base classes are not working. What did i do wrong.  Is there a way to make the override effective also ensure that the object is copied by value.

Someone mentioned it in the IRC as the slicing problem.


In PHP I can do something like this:  public myFunction($variable=0) {     //Do some stuff }   In Javascript, the following does not work:  var myFunction = function(variable=0 ) {      //do some stuff...  };

I've always handled optional parameters in JavaScript like this:  function myFunc(requiredArg, optionalArg){   optionalArg = optionalArg || 'defaultValue';    // Do stuff }   Is there a better way to do it?  Are there any cases where using || like that is going to fail?


There is a huge debate on the internet on the value of $48\div2(9+3)$. I believe the answer $2$ as I believe it is part of the bracket operation in BEDMAS.  yields the same answer. I also believe that if $48\div2\times(9+3)$ was asked it would be $288$ which Mathway agrees with as well. However,  says it is $288$ either way. A friend of mine (who is better at math) told me that there is no such thing as 'implicit multiplication', only shorthand so that is in fact done after the division (going left to right, not necessarily because division occurs before multiplication. But he didn't explicitly give a reason) What is the answer and why?

Given $5x/30x^2$ I was wondering which is the correct equivalent form.  According to BEDMAS this expression is equivalent to $5*\cfrac{x}{30}*x^2$ but, intuitively, I believe that it could also look like: $\cfrac{5x}{30x^2}$  I asked this question on MathOverflow (which was "Off-topic" and closed) and was told it was ambiguous. I was wondering what the convention was or if such a convention exists. According to Wikipedia the .


Many posts here show animated graphics to illustrate solutions about content uncovering. How can I get GIF file for my slides to upload?

As a follow up to , I'd like to know how to generate an animated image (gif) from a series of beamer slides.  Martin Scharrer came up with this example:    Some hints on cropping the PDF file are also welcome. =)


#include <string.h> #include <iostream> using namespace std;  class String {     public:         /* Parameterized Constructor */         String(const char* i_ac)         {             cout<<"Parameterized Constructor";             if(i_ac)             {                 data = new char [strlen(i_ac) + 1];                 strcpy(data,i_ac);             }             else             {                 data = new char[1];                 *data = '\0';             }         }         //Parametrized constructor ends.          /*Copy Constructor */         String ( String& objTemp )         {             cout<<"Copy Constructor";             data = new char[strlen(objTemp.data) + 1];             strcpy(data,objTemp.data);          }          /*Overloaded Assignment Operator */         String operator=(String& objTemp)         {             if(this == &objTemp)             return objTemp;             //Delete Existing data             delete[] data;             data = new char[strlen(objTemp.data)+ 1];             strcpy(data,objTemp.data);             return *this;         }          friend ostream& operator<<(ostream& out, String& s1);      private :         char* data; };  ostream& operator<<(ostream& o1, String& s1) {     o1<<s1.data;     return o1; }  int main() {     String s1("Hello");     cout<<"s1"<<s1;     String s2 = s1;     cout<<"\ns2"<<s2;     String s3(); //doubt     cout<<"\ns3"<<s3; }   On calling String s3(), no constructor is called (I know since I print inside each constructor). However, printing s3 on the following line outputs a 1.  Why isn't a constructor called? How can I make sure one is called?

Is there any good reason that an empty set of round brackets (parentheses) isn't valid for calling the default constructor in C++?  MyObject  object;  // ok - default ctor MyObject  object(blah); // ok  MyObject  object();  // error   I seem to type "()" automatically everytime. Is there a good reason this isn't allowed?


I am learning Python with Automate the Boring Stuff with Python. In chapter 3 it talks about functions and scopes etc. It states that a local scope can use global scopes. However, with the example code below, it is not true? Example Code: def spam():     print(eggs) #Error!     eggs = 'spam local'  eggs = 'global' spam()  I understand logically that because eggs has not been assigned a value before we are executing print and it is exactly what the book says. But my question is since, eggs has been assigned a value in the global scope. Why does Python not revert to the global scope to pull variable. Since again, local can call/pull global but not other local, but global can't pull local. Cheers.

The following code works as expected in both Python 2.5 and 3.0:  a, b, c = (1, 2, 3)  print(a, b, c)  def test():     print(a)     print(b)     print(c)    # (A)     #c+=1       # (B) test()   However, when I uncomment line (B), I get an UnboundLocalError: 'c' not assigned at line (A). The values of a and b are printed correctly. This has me completely baffled for two reasons:   Why is there a runtime error thrown at line (A) because of a later statement on line (B)? Why are variables a and b printed as expected, while c raises an error?   The only explanation I can come up with is that a local variable c is created by the assignment c+=1, which takes precedent over the "global" variable c even before the local variable is created. Of course, it doesn't make sense for a variable to "steal" scope before it exists.  Could someone please explain this behavior?


In GPG, we can use same key pair for encryption and signing. Can't/Shouldn't we do this in RSA. I am using  RSAES-OAEP and RSASSA-PSS, not raw RSA btw.

The RSA signature operation is basically the same as encrypting with the private key.  In particular, both operations use the same kind of keys.  Is it safe to use the same RSA keypair both for encryption / decryption and for signing / verification?


I have defined a custom math symbol, and I am finding it won't scale down as expected (thought it seems some elements of the symbol do scale down. I expect it's related to my definition of \pathgenericinfsym, but I'm not confident enough to modify the command. MWE \documentclass{book} \usepackage{relsize} \usepackage{mathtools} \usepackage{xparse}  \MHInternalSyntaxOn\makeatletter \renewcommand{\xleftrightarrow}[2][]{\ext@arrow 5599\MT_leftrightarrow_fill: {#1}{#2}} \makeatother\MHInternalSyntaxOff  \makeatletter \newcommand*\bigcdot{\mathpalette\bigcdot@{.5}} \newcommand*\bigcdot@[2]{\mathbin{\vcenter{\hbox{\scalebox{#2}{$\m@th#1\bullet$}}}}} \makeatother  \NewDocumentCommand{\genericinfsym}{}{\xrightarrow{\bigcdot}}  \newcommand*\nodeseq[3]{({#1}_{#2}...{#1}_{#3})}  \NewDocumentCommand{\pathgenericinfsym}{}{%     \mathrel{         \vphantom{\genericinfsym}         \smash{\genericinfsym}         \vphantom{\genericinfsym}^{*}     } }  \begin{document}  Normal: \[     \pathgenericinfsym \]  Should be scaled down: \[ \xleftrightarrow[\mathsmaller{\overset{\pathgenericinfsym}{\nodeseq{x}{1}{n}}}]{\text{lpg}} \]  \end{document}

Consider the following MWE.  \documentclass[fontsize=12pt]{scrbook} \usepackage[T1]{fontenc} \usepackage{libertine} \usepackage[libertine]{newtxmath}  \begin{document}     \begin{align*}         v\xrightarrow{e}w &\quad v\overset{e}\rightarrow w \\         \scriptstyle v\xrightarrow{e}w &\quad \scriptstyle v\overset{e}\rightarrow w \\         \scriptscriptstyle v\xrightarrow{e}w &\quad \scriptscriptstyle v\overset{e}\rightarrow w     \end{align*} \end{document}   The result looks like this:    While \rightarrow is changing in size when using \scriptstyle or \scriptscriptstyle, \xrightarrow is not and produces arrows of wrong size and hence height, as well as too little spacing.  Is there a way to fix \xrightarrow?


I have created a entertainment website and i have one question about my site. I have good profiles in tv.com (forum), Imdb (forum boards), rottentomatoes (forum boards), voat.co subvoat , reddit.com subreddit (subreddit of 30 page authority), stackexchange.com and forum.blu-ray. If i will submit links in these sites, will this help my site to rank in google first page or not??   Or what i need to rank well in google and how to get backlinks from my own site too. I saw that big sites like stackexchange.com has got more than 20-30 links form own sites.

What are the best ways to improve a site's position in the Google search results?


Suppose, that M is a set of decreasing functions on a segment [0,1], such that $f(1) = 0$ and I need to find:  $$\underset{f \in M}{inf} \underset{x \in [0,1]}{sup} \frac{x f(x)}{\int\limits_{0}^{1} f(t)dt} $$  I guess, that answer is 0, but I don't know how to prove it. This is my reasoning:   1) let's notice that $xf(x) \geqslant 0, x\in [0,1]$   2) and $\int\limits_{0}^{1} f(t)dt \geqslant 0$, because $F(1) - F(0) > 0$  3) than $\frac{x f(x)}{\int\limits_{0}^{1} f(t)dt} \geqslant 0$  After this step, am I right that I must find a sequence of functions $\{f\}_i$ that $\underset{i \rightarrow \infty}{lim}$ $\underset{x \in [0,1]}{max} f_i = 0$ to prove the statement?

Consider $\bar{C} = C_{d}^0[0,1] $ is the space of continuous decreasing functions, s.a. $f(1) = 0$. We want to determine $\displaystyle \inf_{f \in \bar{C}} \sup_{x\in [0,1]} \frac{x f(x)}{\int_0^1 f(t) dt}$.   I thought about $\displaystyle xf(x) = xf(x) + 1\cdot f(1) = \int^x_1 f(t)dt - \int_1^x tf'(t)dt$. Actually I even don't know whether derivate exists or not.  Now we should consider $\dfrac{\int^1_x \left[tf'(t) + f(t)\right] dt}{\int_0^1 f(t)}$.  Then I thought about Poincare inequality, but fails there. Any hints ?


Let's suppose someone (who's definitely not me...) wants to go to Colombia to know many cities. This fictional character will buy a ticket from São Paulo, Brasil to Barranquilla, Colombia (to go and to come back). This flight has a stop in Bogotá before its final destination.   Then, once in Bogotá, this person suddently decides to know Bogotá and she/he leaves his/her flight and then this person will arrive in Barranquilla to get his/her flight in its scheduled date.  The question is: would the flight company crew accept this person? I mean, this character could get this flight and come back to São Paulo without any problem?

At this link about   what does the author mean by this?   Back to back and hidden city ticketing. Sometimes airlines will charge far more for tickets to that do not include a Saturday night stay, on the assumption that those passengers are business travelers who aren’t flexible and can afford to pay more. Yet those who commute between cities eventually realize that they can purchase one round-trip ticket that covers their first outbound and last return, followed by round-trip tickets to return home on the weekends.


How to use a custom metadata records checkbox field in validation rule over a custom Object?  Is there any way?

I was trying to use custom metadata type in validation rule.  My use case is i want a restriction on digits in phone number on various objects in managed package.I want to give flexibility to subscribers so that they can edit min and max length of phone. I created custom metadata type records and i want to access them in validation rule ..  can anyone suggest me How can i achieve this ?


I have three kinds of file:  Iso file, Directory, Txt file,  ISO: debian7.iso Directory: Archives from /var/cache/apt/archives File: README   I want to burn them into a DVD using command line...  NOTE:  I don't want my iso file be extracted  What I tried is:  sudo wodim  dev=/dev/dvdrw -v -data /path/to/debian7-64bits/   But is gives me errors  What is the best way to do that?  Thanks

I have a DVD ISO file and I want to burn through the terminal.  We have many command formats but I am unable to choose the best & safe one. so please give me a best command to burn the ISO through the terminal.


I just installed Ubuntu. It did not prompt me to remove the old operating system when I installed Ubuntu. How do I either make Ubuntu my default OS at start up without having to choose? Or, how do I delete my old operating system? Which option is better?

When I boot my computer, I get the Windows Boot Manager with Vista selected and Ubuntu as the other item in the list.  If I choose Ubuntu, I get the GRUB menu. I have updated GRUB menus before so I know how that works, but since Windows Boot Manager comes first, I don't know how to change the default.  I looked at this question:  But it seems that that uses GRUB, but the default I want to change is before GRUB even comes up. Any ideas?


I am novice at Java programming, and I'm trying to add a list of files to a crude little media player. Seemingly I've succeeded in achieving what I want with this:  public class MusicPlayerGUI     implements ActionListener {     private static JFileChooser fileChooser = new JFileChooser(System.getProperty("user.dir"));      private JList tracklist;     private MusicPlayer player;     private FileOrganizer organizer;     private List<String> tracks;     private JFrame frame;  public MusicPlayerGUI() {     player = new MusicPlayer();     organizer = new FileOrganizer();     tracks = organizer.listAllFiles();     makeFrame(); }  //Some methods omitted  public void play() {     int fileToPlay = tracklist.getSelectedIndex();     String filenameToPlay = organizer.getFile(fileToPlay);     player.play(filenameToPlay); }  public void setupList() {     tracks = organizer.listAllFiles();     String[] fileList = listAllTracks(tracks);     tracklist.setListData(fileList); }  public String[] listAllTracks(List<String> tracks) {     int numTracks = tracks.size();     String[] fileList = new String[numTracks];     for(int i = 0; i < numTracks; i++) {         String field = tracks.get(i).toString();          fileList[i] = field;     }      return fileList; }   But when I compile, even if it does compile, it gives me an error stating:     [pathname]/classname.java uses unchecked or unsafe operations.   Recompile with Xlint:unchecked for details   And everything in my player works, except it won't play the files, so I'm thinking that there might be a connection between the compiler warning I get, and the fact that the files won't play. Can anyone spot what I'm getting wrong?

For example:  javac Foo.java Note: Foo.java uses unchecked or unsafe operations. Note: Recompile with -Xlint:unchecked for details.


I'm using FileZilla and have found the default LibreOffice Writer not the best for on-the-go code editing.  I have the option to use custom program for text editing, so why not give nano a go. So I'm wondering, where is the nano (shell script?) file located?  I had a quick Google for this question and only found an ArchLinux forum posing the question on .  From the thread, I checked /usr/bin/nano and it's not existant there.

Where are executables for programs stored in Ubuntu?  An application (Komodo Edit) is asking me to identify an application to be used as a web browser. I've become used to just entering the application name as a command for situations such as these, but this scenario got me thinking.   I know in Windows it would just be the relevant application folder in the 'program files' folder, but I'm assuming things are a bit different on Linux?  I thought somewhere like bin would be logical but this appears to standard Linux/Unix applications. Where would I find the binary executable for applications stored on my system?


I am a physics major student who graduated last summer. During my undergrad years and now in my graduate level studies I always worked experimentally. I worked in labs with professors for years. Of course with a moderate amount of studying and with the help of my succesful research career in experimantal optics, I graduated and accepted to the graduate school. I applied for research assistantship and took the exam. Unfortunately I realised that my knowledge and problem solving abilities had become dull over the years. Especially in Classical Mechanics. Could you suggest a book or two for a graduated student who took calculus and a intro. classical mechanics etc. what I mean is I know most of the concepts I don't need to start from the very bottom. I can understand derivations. What I need is a lot of solved examples and exercises with increased difficulty. I know I can't solve a tough problem on my own right now. I just need a guidance. Is there any source that can help me?

Every once in a while, we get a question asking for a book or other educational reference on a particular topic at a particular level. This is a meta-question that collects all those links together. If you're looking for book recommendations, this is probably the place to start.  All the questions linked below, as well as others which deal with more specialized books, can be found under the tag  (formerly ).  If you have a question to add, please edit it in. However, make sure of a few things first:   The question should be tagged  It should be of the form "What are good books to learn/study [subject] at [level]?" It shouldn't duplicate a topic and level that's already on the list   Related Meta:


Overnight I received two "1 new item in your Stack Exchange inbox" emails, both of which have a blank site icon.  Math:   Computational Science:

See .  The problem was that Stack Overflow was trying to access  http://cdn2.sstatic.net/stackoverflowimg/so-fb-logo.png?v=2   When it should have done this:  http://cdn2.sstatic.net/stackoverflow/img/so-fb-logo.png?v=2     I have been experiencing similar problems all over Stack Exchange. For example, here's one from math.SE (click image to enlarge):    From gamedev.SE:    It says:  Failed to load resource: the server responded with a status of 404 (Not Found)   And the URL that returned a 404 was  http://cdn.sstatic.net/math/imgnewsletter-ad.png   Not surprisingly, :  http://cdn.sstatic.net/math/img/newsletter-ad.png   I've been seeing these types of 404s on many other Stack Exchange sites.


I have a problem with Latex, TeXmaker (program). I would like to make a table but the last two boxes are empty, but how can I be sure that there are also lines between the boxes that are empty? Now there is just one big opening? This is the code that I am using:   \begin{tabular}{|c|c|c|} \hline 1 & 2 & 3\\ \hline 4 & 5 & 6\\ \hline 7 \\ \hline \end{tabular}

I'm dealing with the powerful tabularx environment. I was able to obtain a nice table, except for the last column. I need seven columns in total, but at the end I got another half column. I can't understand why!  Here the code I used for building the table:  \begin{table}[h!]  \begin{tabularx}{\textwidth}{|l|*{20}{>{\arraybackslash}X|}}  \multicolumn{1}{c}{}& \multicolthead{3}{\color{RoyalBlue}\textbf{I}}& \multicolthead{3}{\color{RoyalBlue}\textbf{II}} & \multicolthead{3}{\color{RoyalBlue}\textbf{III}} & \multicolthead{3}{\color{RoyalBlue}\textbf{IV}} & \multicolthead{3}{\color{RoyalBlue}\textbf{V}} & \multicolthead{3}{\color{RoyalBlue}\textbf{VI}} \\  \hline  \thead{\color{RoyalBlue}One\\\color{RoyalBlue} Time} & \cellcolor[HTML]{D3D3D3} & \cellcolor[HTML]{D3D3D3} & & \multicolumn{3}{l|}{} & \multicolumn{3}{l|}{} & \multicolumn{3}{l|}{} & \multicolumn{3}{l|}{} & \multicolumn{3}{l|}{} \\  \hline  \thead{\color{RoyalBlue}Two\\\color{RoyalBlue} Times} & & & \cellcolor[HTML]{D3D3D3} & \cellcolor[HTML]{D3D3D3} & & & \multicolumn{3}{l|}{} & \multicolumn{3}{l|}{} & \multicolumn{3}{l|}{} & \multicolumn{3}{l|}{} & \\  \hline  \thead{\color{RoyalBlue}Three\\\color{RoyalBlue}Times} & \multicolumn{3}{l|}{} & & \cellcolor[HTML]{D3D3D3} & \cellcolor[HTML]{D3D3D3} & \cellcolor[HTML]{D3D3D3} & \cellcolor[HTML]{D3D3D3} & \cellcolor[HTML]{D3D3D3} & \cellcolor[HTML]{D3D3D3} & \cellcolor[HTML]{D3D3D3} & \cellcolor[HTML]{D3D3D3} & \cellcolor[HTML]{D3D3D3} & & & \multicolumn{3}{l|}{} \\   \hline  \thead{\color{RoyalBlue}Four\\\color{RoyalBlue} \& Times} & \multicolumn{3}{l|}{} & \multicolumn{3}{l|}{} & \multicolumn{3}{l|}{} & \multicolumn{3}{l|}{} & & \cellcolor[HTML]{D3D3D3} & \cellcolor[HTML]{D3D3D3} & \cellcolor[HTML]{D3D3D3} & & \\  \hline  \end{tabularx} \caption{{Caption}} \end{table}   Which produces the following output:    Does anyone have an idea?


Payment due date of my credit card is on March 4th. And I already paid full amount of balance on Feb 26th. If I use my credit card today, which is March 3, should I pay another one by March 4?  (Hi,jamesqf. Even though I already paid, I thought I had to pay it again because it was the amount I used before the payment due date date.)

First of all, I am a resident of Canada.  I am  new to credit cards, so I hope my question makes sense. I've had my card for a few months ago and I've always paid the balance in full by the time the due date rolls around. Just out of curiosity, say the day after tomorrow was my due date. If I made a purchase tomorrow and didn't pay it off by the day after tomorrow, would I be charged any interest on it? Is there any negative ramifications at all for doing this?  Thanks.


In Catan, can player one build a road around a hex, and player two build a settlement between two of player one's road sections while being connected to his own roads from the third side? If so, does this affect Longest Road?  What about the opposite case: if two players have roads coming up to a corner where one of them already has a settlement, can the other one continue building from the other side?

Let's say my opponent (o) has a road network:  o - - - - - o         |        x   as x, can I:  o - - -x- - o        |        |        x   ?  And break his already existing road?  My question is not whether or not this will break his road; my question is if it is legal for me to build there and break an already-established road.  At a previous game, there was considerable controversy as to whether this was a legal place to build a settlement.


If I create a new object that requires   \begin{}   and   \end{}   I want the contents within the braces to auto-synchronise with each other.   For example  \begin{itemize}     \item Example text \end{itemize}   And later I decide that I want an enumerated list, and I change one of the contents inside the { } to enumerate the other one should too automatically.  \begin{enumerate}     \item Example text  % Contents of {} should update here automatically if changed above % Or vice versa   \end{enumerate}   This 'auto-synchronization' sometimes occurs accidentally so I think it is an inbuilt feature, but I do not know how to trigger it.    Edit    by @Troy also explains this issue and he has used better terminology (mirroring vs auto-synchronisation). However, in that answer, the information by @Troy was additional and not what the OP was asking for.

When I autocomplete an environment, I get a red box (which I now know, from  is called a placeholder.)   What are these placeholders for, what functionality is associated with them, and what is the intended workflow for using them? (I think this information is probably all on here somewhere, spread over a series of different questions/answers. But it would be great to have everything in one place and to know I'm not missing anything)


I'm using Ubuntu 18.04.2. I want to be able to do like I could back when I used Windows where you have a dock on each screen but all screens only show the programs / active windows that are on their respective screens.   I have searched and searched and have not found the answer to this. Can someone please tell me how to do this? It is the only last thing I have to figure out since my switch to Ubuntu full time.

I am using Ubuntu 18.04 (with Linux kernel 4.15.0-33-generic) on a setup with laptop and an external monitor. Is there a way to make the dock in Ubuntu 18.04 only display the windows from the current screen. There was a similar feature in Ubuntu 16.04.  In short if an app is only opened on one of the screens it was still displayed in the launcher but with a different indicator. When there are two windows of an app (e.g. I have two gedits or two chromes opened) one for each screen, clicking on the icon in the dock opened the window for the corresponding screen (instead of displaying a picker with the two windows).   Is there a way to have similar configuration for Ubuntu 18.04?


The shadows in my scene aren't working as I would like. The shadow beneath the shelf is 'blocked out'. I take it Blender is reading the shelf and supports as a single object.  Is there a way to overcome this?  I'm using 2.8 with Eevee  Here is link to Blender file:   Thanks      Issue fixed:

In the images below, I have a cube that is sticking up about two thirds through a plane. But, despite the fact that the cube is not hovering over the plane, the shadow seems to indicate otherwise. How can I fix this shadow?


Since 10k+ users don't have any control over comments, why am I shown "too many comments" flags in the moderator tools?      What can I do with these flags other than simply re-flagging them for a moderator?  What do moderators do with them?

Every once in a while I take a look at the tools page and see a high number of flags - like right now.  And there is indeed some pretty spammy stuff in there.  It's fairly self-evident what to do with flagged questions, I think - just vote to close/delete if the flags are in fact accurate.  But what about flagged answers?  It doesn't really seem like there's much we can do about those.  Should we:   Flag them again, hoping to bump the answer down and/or get it auto-deleted? Flag for (real) moderator attention, i.e. to confirm "yes this is really spam"? Just leave them alone (assuming that a proper mod will find it soon)?   Also - is there any particular action we should be taking if a post is erroneously flagged - i.e. somebody got annoyed that a question wasn't marked CW?  Some guidelines on how best to use this feature would be appreciated.


The question is that simple, Why isomorphisms are important ? I know how we define mathematically isomorphisms, and I know what it means, if two things are isomorphic they are essentially the same thing. I want you to give some examples where they answer the question "Why isomorphisms are important ?" because I am an undergraduate I don't have that much experience to give my self that example. I think isomorphism like the analog of matrix similarity, meaning if we want to find a big power of a matrix we don't calculate all the matrix multiplications we just find the Jordan form or the diagonal matrix, and we take it from here. So we make problems easier and faster to calculate by connecting them with isomorphisms. Do you have in mind a fundamental example? Or one you think condenses the beauty of mathematics. Thank you.

In many courses, say Linear Algebra, Group Theory, Topology, instructors often say that knowing that certaing objects are isomorphic, sometimes makes life easier because we can work with more friendly objects.  Is there any example of using isomorphism concept to solve a non trivial concrete problem?   I must say, I'm not looking on important or famous isomorphic objects, but on non trivial application of the concept of isomorphism used in order to solve another kind of problem.


I posted , which I'm aware is an exact duplicate of   The older question is more than 5 years old and it's not going to get any new attention any time soon. If the newer question got an answer, we could mark the older question as a duplicate. Additionally, in this particular case it's a meta bug report, and the SE dev team may now have more time and resources to fix the bug; bringing it to their attention again may result in a bugfix.  At first I was quite sure that it should be fine, but thinking about it some more I'm not 100% sure. Is it appropriate and/or acceptable to post an exact duplicate of a question that has no answer? Does this differ between meta and non-meta?

Yesterday i was trying to answer 2 questions on SO, but when i finished typing the questions was closed because they were duplicate.  One of the question was answered by a really not that good of an answer (so the question is closed, but that answer is the only one to show), and the second question had no answer at all.  Now if someone will see the first question and its answer, he will be giving the sense that this answer is ok to work with it, and no one can give other answers, or they won't bother as that question is closed, so those users will be using the wrong way.   The second answer is actually more important, because the question had actually couple of right answers, and couple of right ways to do what the OP wanted, but the duplicate that was linked to it was a specific one way (the OP asked for a specific way to do it, so i can't answer with the other way to do it as it won't be answering the question), but again, because the question is closed, no one will bother answering it or take a look if its really a duplicate?  I don't have enough points to comment or chat, so i can't do anything about it, but SO is about helping people to understand code, the first question was a typo of the OP and needed exactly 2 lines to answer it (first line the code, and second is where his problem was), the second question had few answers but yet the duplicate only specifically talking about one of those answers.  So i kinda have 2 questions, do we really need to close questions without giving any answer? If a questions have couple of ways to do it, does it really a duplicate of a question that is only specifically talking about 1 way to do it?


The  laptop comes with Windows 10. After disabling BitLocker, fast boot, and secure boot, I could install ubuntu 18.04. The issue now is to recognise the WiFi card.   All the answers I found on Google doesn't work. It seems that these XPSs come with a WiFi card produced by Intel:  :~$ sudo lshw -C network [sudo] password for rodrigo:    *-network UNCLAIMED               description: Network controller        product: Intel Corporation        vendor: Intel Corporation        physical id: 0        bus info: pci@0000:02:00.0        version: 1a        width: 64 bits        clock: 33MHz        capabilities: pm msi pciexpress msix cap_list        configuration: latency=0        resources: memory:9e200000-9e203fff   *-network        description: Ethernet interface        physical id: 3        logical name: enx98e743d58cb6        serial: 98:e7:43:d5:8c:b6        size: 100Mbit/s        capacity: 1Gbit/s        capabilities: ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation        configuration: autonegotiation=on broadcast=yes driver=r8152 driverversion=v1.09.9 duplex=full ip=172.16.1.134 link=yes multicast=yes port=MII speed=100Mbit/s   Edit: The linked answer is pretty old and was answered for 16.04 which doesn't have the required driver. The accepted answer says it was solved on 17.04, but isn't the case here as I'm using the version 18.04    Edit 2  After following  I could get the wifi working (with a question mark over the wifi icon though). But now the DNS doesn't work:   Edit 3  As I commented on Edit 2, after installing the drivers on ubuntu, the DNS stopped working correctly. i.e. it works for some domains like google.com and facebook.com, but it doesn't work for github.com or askubuntu.com.  Strangely enough, I entered on Windows 10, and now it has the same behaviour as Ubuntu, i.e. it can't resolve all domains. How could some drivers for Ubuntu break Windows' DNS resolver?

In order to install Ubuntu on the XPS 7590 (I've heard the same was true for the 9570 as well) you have to open the boot menu and modify BIOS settings to turn "Secure Boot" off and to switch SATA mode from RAID to AHCI.  Doing the above I was able to fully install Ubuntu 18.04, however I needed a hard-wired internet connection to handle any downloads/updates because, under the WiFi settings no networks were available and I was instead greeted by the message "No WiFi Adapter Found". None of the existing answers on this forum, StackOverflow, or even working with Dell Support were able to solve this issue for me.


I was using the following:  String x; ... ... // x gets set somewhere in this code String y = x.replaceAll("\\s+", " ").trim();  Then I found org.apache.commons.lang3.StringUtils.normalizeSpace() which does the same thing.  So at the top of my class I added  import org.apache.commons.lang3.StringUtils;  and called  String y = normalizeSpace(x);  but it gave me a method not found error and suggested I create the method.  So I tried  import org.apache.commons.lang3.StringUtils.*;  but the same problem.  Anyone have an idea what is wrong?  Yes I can, and do, use   String y = org.apache.commons.lang3.StringUtils.normalizeSpace(x);  but it gets awkward typing the entire path every time.  Oh, and I did not get a syntax error on either of the import statements. And I guess I could go back to the replace and trim but StringUtils has a lot of other methods which would be good to use also.

Just got a review comment that my static import of the method was not a good idea. The static import was of a method from a DA class, which has mostly static methods. So in middle of the business logic I had a da activity that apparently seemed to belong to the current class:  import static some.package.DA.*; class BusinessObject {   void someMethod() {     ....     save(this);   } }    The reviewer was not keen that I change the code and I didn't but I do kind of agree with him. One reason given for not static-importing was it was confusing where the method was defined, it wasn't in the current class and not in any superclass so it too some time to identify its definition (the web based review system does not have clickable links like IDE :-) I don't really think this matters, static-imports are still quite new and soon we will all get used to locating them.  But the other reason, the one I agree with, is that an unqualified method call seems to belong to current object and should not jump contexts. But if it really did belong, it would make sense to extend that super class.  So, when does it make sense to static import methods? When have you done it? Did/do you like the way the unqualified calls look?  EDIT: The popular opinion seems to be that static-import methods if nobody is going to confuse them as methods of the current class. For example methods from java.lang.Math and java.awt.Color. But if abs and getAlpha are not ambiguous I don't see why readEmployee is. As in lot of programming choices, I think this too is a personal preference thing.   Thanks for your response guys, I am closing the question.


This question is related to flagging a profile I presume, which is an open problem-but I was wondering-     Is there a specific way to flag an offensive avatar image?   Or do I need to somehow contact the moderators of the particular stack in another way  (mail?).

There are already at least a couple of questions (, ) about how to handle potentially inappropriate profile pictures, but the answer given in both cases (and other duplicates of those) essentially comes down to "flag it and let the moderators deal with it." Well, as a moderator, how exactly am I supposed to deal with it? As far as I can tell, Stack Exchange does not have a clear policy about what sorts of images are inappropriate. The closest thing is this clause in :  Subscriber represents, warrants and agrees that it will not contribute any Subscriber Content that [...] (d) is libelous, defamatory, abusive, threatening, harassing, hateful, offensive or otherwise violates any law or right of any third party....  but people do not always agree on what constitutes hateful or offensive content, or even on what constitutes libel or defamation (considering the prevalence of lawsuits). I don't think it's reasonable that my own opinions on the topic should be the basis for judging whether a picture is acceptable or not, simply because I'm the one tasked with handling (or not handling) the flag. I'd like to establish a more specific policy to guide moderators tasked with handling potentially inappropriate profile pictures. Certainly I'm not suggesting we set up an exhaustive list of inappropriate profile pictures, but something more than what is in the ToS would be useful. For example: "X, Y, and Z are always inappropriate; for anything else, defer to the community team," with specific details about what X, Y, and Z are. I have my own ideas, but I'll omit them to avoid influencing the responses.


I crave to learn the nitty-gritty of attitude dynamics - namely I want to get really up close and personal with angular momentum, gyroscopic motion, non-inertial effects. I'm looking for a resource which teaches me straight-forward yet rigorous methods for analyzing spinning motion dynamics - as my question states, gyroscopic motion is an example.  So far I read Kleppner's An introduction to Mechanics part on gyroscopic motion. I don't like how methods are outlined for specific examples - I want a resource that outlines general equations and uses them to work out solutions to specific examples.  Equally important is a book that is not condescending. What I mean is I don't want to read an author who skips parts of demonstrations or refers me to this and that. I want someone who talks to me with a level head and walks me through each step (the best example of such an author is Donald Kirk from Optimal Control Theory: An Introduction).  Do you know of such books or YouTube, etc. video series? Thanks a lot!

Every once in a while, we get a question asking for a book or other educational reference on a particular topic at a particular level. This is a meta-question that collects all those links together. If you're looking for book recommendations, this is probably the place to start.  All the questions linked below, as well as others which deal with more specialized books, can be found under the tag  (formerly ).  If you have a question to add, please edit it in. However, make sure of a few things first:   The question should be tagged  It should be of the form "What are good books to learn/study [subject] at [level]?" It shouldn't duplicate a topic and level that's already on the list   Related Meta:


I am not able to see my hard disk in disks. I think I have accidentally formatted it but the hard disk is not listed even in the terminal. I tried otherwise I am now using Ubuntu without installation.   Has my hard disk been damaged? If that is the case what can I do, please?

I am trying to install Ubuntu 16.04 LTS on a Dell XPS 13 (9350). The laptop came with Windows 10 pre-installed. I am installing from a pendrive but I think the issue would be the same if I used e.g. a USB DVD drive.   Dude, where's my hard drive?  I am blocked because the installation program cannot find 8.6Gb of free space on my hard drive despite the fact that there are hundreds of Gb free according to Windows. Digging a bit into the problem, it seems that Ubuntu cannot see my hard disk at all.    This is the output of GParted:    I am not sure what that drive mounted at /cdrom is, but it seems the only device that exists in the system that is not a RAM disk or a loop device:   Content of /proc/partitions:   ubuntu@ubuntu:~$ cat /proc/partitions   major minor  #blocks  name     1        0      65536 ram0     1        1      65536 ram1     1        2      65536 ram2     1        3      65536 ram3     1        4      65536 ram4     1        5      65536 ram5     1        6      65536 ram6     1        7      65536 ram7     1        8      65536 ram8     1        9      65536 ram9     1       10      65536 ram10     1       11      65536 ram11     1       12      65536 ram12     1       13      65536 ram13     1       14      65536 ram14     1       15      65536 ram15     7        0     130048 loop0     7        1    1104188 loop1     8        0    1970239 sda     8        1    1953439 sda1   Summary of fdisk -l:   ubuntu@ubuntu:~$ sudo fdisk -l |grep Disk Disk /dev/ram0: 64 MiB, 67108864 bytes, 131072 sectors Disk /dev/ram1: 64 MiB, 67108864 bytes, 131072 sectors Disk /dev/ram2: 64 MiB, 67108864 bytes, 131072 sectors Disk /dev/ram3: 64 MiB, 67108864 bytes, 131072 sectors Disk /dev/ram4: 64 MiB, 67108864 bytes, 131072 sectors Disk /dev/ram5: 64 MiB, 67108864 bytes, 131072 sectors Disk /dev/ram6: 64 MiB, 67108864 bytes, 131072 sectors Disk /dev/ram7: 64 MiB, 67108864 bytes, 131072 sectors Disk /dev/ram8: 64 MiB, 67108864 bytes, 131072 sectors Disk /dev/ram9: 64 MiB, 67108864 bytes, 131072 sectors Disk /dev/ram10: 64 MiB, 67108864 bytes, 131072 sectors Disk /dev/ram11: 64 MiB, 67108864 bytes, 131072 sectors Disk /dev/ram12: 64 MiB, 67108864 bytes, 131072 sectors Disk /dev/ram13: 64 MiB, 67108864 bytes, 131072 sectors Disk /dev/ram14: 64 MiB, 67108864 bytes, 131072 sectors Disk /dev/ram15: 64 MiB, 67108864 bytes, 131072 sectors Disk /dev/loop0: 127 MiB, 133169152 bytes, 260096 sectors Disk /dev/loop1: 1.1 GiB, 1130688512 bytes, 2208376 sectors Disk /dev/sda: 1.9 GiB, 2017525248 bytes, 3940479 sectors Disklabel type: dos Disk identifier: 0x00000000   Result of fdisk of the only non-loop non-RAM device (not sure this is relevant):   ubuntu@ubuntu:~$ sudo fdisk -l |grep -A 50 sda Disk /dev/sda: 1.9 GiB, 2017525248 bytes, 3940479 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0x00000000  Device     Boot Start     End Sectors  Size Id Type /dev/sda1  *      129 3907007 3906879  1.9G  c W95 FAT32 (LBA)   I am blocked at this point. Any help will be much appreciated.   Additional information (following comments):   Running dmesg |grep -i sata shows (among others) eight lines that suggest some kind of error:   ata1: SATA link down (SStatus FFFFFFFF SControl FFFFFFFF) ata2: SATA link down (SStatus FFFFFFFF SControl FFFFFFFF) ata3: SATA link down (SStatus FFFFFFFF SControl FFFFFFFF) ata4: SATA link down (SStatus 0 SControl 0) ata5: SATA link down (SStatus 0 SControl 0) ata6: SATA link down (SStatus 0 SControl 0) ata7: SATA link down (SStatus 0 SControl 0) ata8: SATA link down (SStatus 0 SControl 0)  I have "Restarted" windows instead of only "Shutdown" it to avoid problems with "fast startup", following some recommendations I have read of other users having problems installing Linux on Windows 10 laptops.ago   Regarding SATA, the BIOS says: "SATA Operation: RAID ON". The other two options available are "Disabled" and "AHCI".    I have followed the instructions of these two pages from Dell: , .


I created a user named shut so that whenever one logs in using that username the machine would shut down. For that I placed the below command in the end of the .profile.  exec sudo shutdown -h now   But this didn't serve the purpose. When the user shut logs in, rather than the machine shutting down, the login screen is coming back. So the user isn't able to log in but at the same time getting back the same login screen.  The reason I feel is that because password for the user shut isn't provided , the machine isn't shutting down. And because of exec, the login screen is coming back (which is fine).  Now to solve my work, I need a way so that it would automatically take my password when the above sudo command executes. I checked man sudo and I think -A option has to be used.   Following that man page, I ran  SUDO_ASKPASS=/home/ravbholua/pass.txt  export SUDO_ASKPASS   Then to check whether it's working, I ran  ravbholua@ravbholua-Aspire-5315:~$ sudo -A pwd  sudo: unable to run /home/ravbholua/pass.txt: Permission denied   From this output, it means this path file has to run and provide my password as output to sudo. What earlier I thought, it would take the password from this file named pass.txt, so I entered my password in this file. But no!!!!!!!  Any suggestions please!

I need to run something as sudo without a password, so I used visudo and added this to my sudoers file:  MYUSERNAME ALL = NOPASSWD: /path/to/my/program   Then I tried it out:  $ sudo /path/to/my/program [sudo] password for MYUSERNAME:    Why does it ask for a password? How can I run/use commands as root with a non-root user, without asking for a password?


(Similar to the above question, but unfortunately I could not see where to go with the above hint. I'm sure it's obvious, but right now I feel that I am missing the point - even just a hint giving a small explanation would be appreciated.)     We say that a group, $G$, acts freely on a set S if for any non-trivial $g \in G$, and any $s \in S$, we have $g · s = s$. Let $φ(g, s) = g · s$ and $ψ(g, s) = g ∗ s$ be two free actions of a finite group G on a finite set S. Show that there is a function $f : S → S$ such that   $$f(g · s) = g ∗ f(s)$$   for all $g ∈ G, s ∈ S$.   I am able to prove this in the case that $G$ is cyclic, but not otherwise. I am thinking that a possible way forward might be to consider the orbits of $S$ as we can see (from the Orbit-Stabiliser theorem, for example) that each orbit of $S$ has the same size for both actions; at this point I am just confusing myself though, and I would appreciate any hints on how to proceed.

Let $A, B:G\to \mathrm{Aut}(X)$ be two free group actions, where $X$ is a set and $G$ a group. A group action, $A$, is free if for all $g\in G\setminus{e}$, $A(g)x\neq x$ for all $x\in X$.Then there exists a function $f:X\to X$ such that for all $g\in G, x\in X$ $$f(A(g)x)= B(g)f(x).$$    I've been completely stumped for some time! How ought one think about such a question? I can't even think of a candidate $f$ or of some simple properties it ought satisfy! I've managed to dig up that the action being free is equivalent to $(g, x)\mapsto (A(g)x, x)$, $G\times X \to X\times X$ being an injection, but haven't been able to make use of this fact.


I have a touchy laptop, and with Ubuntu 18, the screen rotates with it. Superb. However, normally the dock is at the left (which for screen real estate is optimal), but when the screen is in portrait mode, it ought to be at the bottom.   Is this possible at all, and if so, how?

In my current configuration, I have a dock (which shows application icons) on the left of the screen. I was wondering whether it is possible to move the dock to the top when the monitor is rotated 90 degrees (so to avoid narrowing down the width of the screen). Also, I want the dock to be back in the original position when I go back to the horizontal monitor orientation. Could someone help me do this?  Environment  I am running Ubuntu 18.04 and using the default gnome desktop environment. My computer is a 2-in-1 laptop which automatically rotates screen based on device orientation.   Current Attempt  I looked into possible gnome extensions that would do this, but  did not have such options.


I am starting ph.D in neutrino physics-ph. I've read some papers on discrete symmetries and neutrino mass models. Neutrino flavor models are built using irreducible representations of discrete groups, or even SM is based on irreducible representation of certain groups only. Why is it possible only in irreps? Why can't we use any other representations (reducible, adjoint reps or any other if there is any)?

Emphasis is on the irreducible. I get what's special about them. But is there some principle that I'm missing, that says it can only be irreducible representations? Or is it just 'more beautiful' and usually the first thing people tried?   Whenever I'm reading about some GUT ($SU(5)$, $SO(10)$, you name it) people usually consider some irreducible rep as a candidate field. Also, the SM Lagrangian is constructed in this way. (Here, experimental evidence of course suggests it.)


I've just read this in a review:     Thankfully, the energy efficient Qualcomm chip helped the handset   reach a best-ever score of 17 hours and 30 minutes in our continuous   video rundown test. Compared to the outgoing model, which lasted ten   hours 43 minutes in the same test   The first part uses 17 hours while the second part uses ten hours.  Which is correct? What are the rules to determine when which should be used?

Possible Duplicate:    Based on , is there a rule of thumb when a number should be spelled out? These examples are easy:  I have two brothers. It's exactly 823 miles to New York.  But do I have 15 minutes of fame, or fifteen minutes of fame? Edit:   asks how the practice of spelling out numbers originated; I'm looking for specific guidelines.


I am provided a template and now I want to print my bibliography. The template comes with a LaTeX-class file, which contains the entry:  \usepackage[backend=biber,citestyle=ieee,sorting=none,dateabbrev=false,urldate=comp]{biblatex}  In the .tex file after some specifications such as \documentclass{myTemplte}, there is the entry \addbibresource{./library.bib}. Now, here is how I try to create one quotation:   \begin{document} \begin{figure}[h]     \centering     \def\svgwidth{\linewidth}     \import{pic/}{someFigure.pdf_tex}     \caption{Description, source: \cite{2018}.}     \label{Figure} \end{figure}  \printbibliography[heading=bibintoc]   Now, instead of a nice [1], the bibtexkey 2018 appears and the bibliography doesn't get printed at all. Can anyone think of a reason for this? Or is this question stupid to ask, because it cannot be recreated?  By the way, I am using JabRef to create my entries in my .bib file. For this particular source, I am using:   @Online{2018,   title = {Open Clip Art},   date  = {2018-07-12},   url   = {https://openclipart.org/}, }   When I run the "Bibliography" command (F8), these three errors occur:   I found no \citation commands---while reading file Report-Template.aux I found no \bibdata command---while reading file Report-Template.aux I found no \bibstyle command---while reading file Report-Template.aux

Running the minimal example  \documentclass{article} \usepackage{filecontents} \begin{filecontents*}{\jobname.bib} @ARTICLE{example,   author  = {Other, Anthony Norman},   title   = {Some things I did},   year    = {2014},   journal = {J.~Irrep. Res.},   volume  = {1},   number  = {1},   pages   = {1-10} } \end{filecontents*} \usepackage[backend=biber]{biblatex} \addbibresource{\jobname.bib} \begin{document} Hello\cite{example}. \printbibliography \end{document}   I get the warning There were undefined references.  I have read  and know that I need to run:   LaTeX Biber LaTeX   However, my editor is only set up to run BibTeX. How do I go about setting up my editor/IDE to be able to run Biber, and how do I run the LaTeX/Biber/LaTeX cycle?  Answers (sorted alphabetically by editor name)                    Answer guidelines   Each answer should be for one editor. If the editor is cross-platform, if possible give a single answer with notes covering the minor platform variations. Please edit the question to include new answers in the 'link list' Each answer should be 'stand alone', i.e. don't say 'It's almost the same as editor Y but ...' for the editor part Instructions for 'build tools' such as arara or latexmk are welcome but should explain how to set up the editor in question as not all editors allow simple addition of arbitrary tools


Here's a novel that I cannot recall correctly the name. It'll be great if someone could help identifying its name.  WARNING: POTENTIAL SPOILERS BELOW  Hints:   It's a short novel. The main idea is that an individual lives the life of all human beings (to be explained below). Here's the storyline that I recall (sorry but it might be different from the actual novel, as I may make mistakes in memory):   There was an individual A who lived his whole life and died. After his death, he met an angel, who told him that he would be re-born and start a life as another person B. The same individual then lived through the whole life of B. After his death, he met the same angel. Then the same process repeated. The same individual lived lives of another person C, another person D, and so on. The same angel then revealed it: All those billions of people, past, present, and future, were all this same person experiencing different phases / roles. And when he / she finished experiencing all lives of human beings, he / she would eventually become one of the real humans, just like this angel itself.  I read it in the Chinese language. But I cannot now recall whether it's written by a Chinese author, or translated into Chinese. I didn't read the story from a book. I probably read it on my kindle or my laptop.

I remember reading a short story a few years ago and I would like to reread read it again. As far as I remember it went a little like this:  You are in a car with your family and a truck hits it, but you are the only one to die. When you regain conciousness you are [in some place that I can't remember] and you see a person (I'm going to call the person as Bob from here, but it's possible the gender wasn't specified) and ask him about your wife/family, Bob tells you that you are dead and your wife/family are/will grieve for you for a time, but your wife get over you and marry someone else. Bob then basically tells you that you are not actually a human but a being like him and their kind created the concept of the universe, time, ethics, morality etc for you because you are young and it will teach you the above. Since the universe is made just for you, everybody in the universe is you. When you die you are reborn as someone else on Earth, but the past memories are blocked but you do start to gain them back if you stay in the place you are in, but Bob wants to send you back to experience more because you are not finished just yet.  One of the last things Bob says to you is that you will be born this time as a farm girl in China in X year.   I have tried Googling this, but I was only able to get results like "God did not create the universe, gravity did, says Stephen Hawking", "IS THERE A GOD?" and "Quotes About Universe". Any help would be great.


When I asked here why neutrons in nucleus (with protons) don't decay I was told that it would require energy for the neutron to decay, it wouldn't give energy. And since that wasn't really what I wanted to hear, since I already knew that, I'm now asking a similar question.  I know that strong force holds protons and neutrons together in nucleus, but how does that effect a neutron in a way that it doesn't decay?

I know outside a nucleus, neutrons are unstable and they have half life of about 15 minutes. But when they are together with protons inside the nucleus, they are stable. How does that happen?  I got this from wikipedia:     When bound inside of a nucleus, the instability of a single neutron to beta decay is balanced against the instability that would be acquired by the nucleus as a whole if an additional proton were to participate in repulsive interactions with the other protons that are already present in the nucleus. As such, although free neutrons are unstable, bound neutrons are not necessarily so. The same reasoning explains why protons, which are stable in empty space, may transform into neutrons when bound inside of a nucleus.   But I don't think I get what that really means. What happens inside the nucleus that makes neutrons stable?  Is it the same thing that happens inside a neutron star's core? Because, neutrons seem to be stable in there too.


I'm studying Halmos' Naive Set Theory. In Section 9, Families, he mentions of the generalized Cartesian products of families of sets, and considers the projection maps as defined below. Let $\{X_i\}_{i\in I}$ be a family and $J\subset I$. Then the map $f:\Pi_{i\in I}X_i\to\Pi_{j\in J}(X|J)_j$ defined by $f(x) = x|J$ for all $x\in \Pi_{i\in I}X_i$. Halmos call this map as projection from $\Pi_{i\in I}X_i$ onto $\Pi_{j\in J}(X|J)_j$ (page 36). This is before the axiom of choice is introduced. However, I think that without AC, we can't conclusively say that $f$ is indeed a surjection (even if $\forall i(X_i\neq\emptyset)$). Am I correct?  For a function $g:Y\to Z$ and for $X\subset Y$, $f|X$ denotes the restriction of $f$ to $X$.

Yesterday I pose a question where I ask about the correctness of a proof where I shown that the Axiom of Choice implies that for any not empty collection of not empty sets the projection defined on their cartesian product  are surjective funcions, so then I asked to me if from the assertion about the surjectivity of the projections I can argue the Axiom of Choice. Here following the link of the question where I proved the first implication: .   Well could someone help me, please?


A LOT OF PEOPLE ASKING HOW TO FIX OR RESTORE THE WINDOWS STORE. This is a fix I made after a lot of stuffing around, should work for people on Windows 10.   Download the TakeOwnership file from MediaFire and unzip it:   Run the file named:  InstallTakeOwnership.reg Navigate to:  C:\Program Files\WindowsApps Right click on the  'WindowsApps'  folder and click on  'Take Ownership'  in the context menu (This will give you permission to access the WindowsApps folder) Now open the  'WindowsApps'  folder and find a folder named  'Microsoft.WindowsStore_11909.1001.7.0_x64__8wekyb3d8bbwe'  and open it (your folder name may be slighty different) Find the file named  'AppxManifest.xml'  and right click and copy this file Go to  'My Computer'  or  'This PC' and go to your Local Disk (C:) Paste the  'AppxManifest.xml'  file directly in your (C:) directory Open and run 'Command Prompt' as an 'Administrator'. Copy and paste the command:  PowerShell -ExecutionPolicy Unrestricted Copy and paste the command:  $manifest = (Get-AppxPackage Microsoft.WindowsStore).InstallLocation + '\AppxManifest.xml' ; Add-AppxPackage -DisableDevelopmentMode -Register $manifest Close command prompt and open the Run command by pressing  'Windows Key + R'  and type in  WSReset.exe  and hit enter Wait for the WSReset command to close and restart your PC. Welcome back to the Windows Store!! :) Guide created by: Luke Jordan 30091990.. PLEASE LIKE AND SHARE IF IT HELPED YOU!!

I had remove the Microsoft Store application. Yes, totally remove the app. Do not ask how and what for. :)  Is there a convenient way to set it up again or restore it? Anything except "system restore"...  Upd. I used  to remove everything. And it works so good that nothing can be found again. :) or :(.  [Get-AppxPackage Microsoft.WindowsStore] returns nothing.  Search for [Microsoft.WindowsStore] returns only:   C:\Documents and Settings\All Users\Microsoft\Windows\AppRepository\Packages\Microsoft.WindowsStore_2015.7.1.0_neutral_split.scale-200_8wekyb3d8bbwe [Folder is empty] C:\Documents and Settings\All Users\Microsoft\Windows\RetailDemo\OfflineContent\Microsoft\Content\en-gb\AppData\Microsoft.WindowsStore_8wekyb3d8bbwe [Folder contains only 3 jpg] C:\Documents and Settings\All Users\Microsoft\Windows\RetailDemo\OfflineContent\Microsoft\Content\Neutral\AppData\Microsoft.WindowsStore_8wekyb3d8bbwe [Folder contains only 3 jpg] C:\Documents and Settings\All Users\Microsoft\Windows\AppRepository\Microsoft.WindowsStore_2015.7.1.0_neutral_split.scale-200_8wekyb3d8bbwe.xml C:\Documents and Settings\All Users\Microsoft\Windows\AppRepository\Microsoft.WindowsStore_2015.701.14.0_neutral_~_8wekyb3d8bbwe.xml


I want to search for lines with 'word1' XOR 'word2' in a text file. So it should output lines with word1, word2 but not the lines with both of these words. I wanted to use the XOR but I do not know how to write that in linux command line.  I tried:  grep 'word1\|word2' text.txt grep word1 word2 text.txt grep word1 text.txt | grep word2 grep 'word1\^word2' text.txt   and many more, but could not get sucess.

I'm trying to use grep to show only lines containing either of the two words, if only one of them appears in the line, but not if they are in the same line.  So far I've tried  grep pattern1 | grep pattern2 | ... but didn't get the result I expected.


How can I install an iso file on a USB while I'm using a live Ubuntu OS?  I want to make a persistent USB drive with Ubuntu 14.04 32 bit.  I have Ubuntu 14.04 32 bit on a USB in an iso file, I'm currently running Ubuntu 14.04 lts 64 bit live how can I install the 32 bit iso file on the USB?  And I can't use Unetbootin, it says: "E: Unable to locate package unetbootin"

I want to install Ubuntu to a USB hard drive so that it will run on all systems, that can run the LiveCD and store persistent data on a regular ext4 partition rather than a casper-rw file. In every other way it should behave like a regular Ubuntu installation. The problem With Startup Disk Creator one is able to put the LiveCD image on a USB-device. Changes can be made persistent but are stored in a file that is limited to a few GB in size. Said persistent file (additionally to being size restricted) has the problem that it isn't readable like data on a normal partition.* My question So how do I get the LiveCD on a USB disk in such a way that the changes are stored in a normal partition rather than a persistence file? Also the persistent changes shouldn't be restricted to a few GB in size but use whole partition of many 100 GB if need be. I suspect there is a tutorial out there for this, but my google-fu is just not good enough to find it. tl;dr: Sytem should run on all hardware configurations, have full functionality of the LiveCD and be stored on a regular ext4 partiton without using ramdisks and casper-rw. FU casper-rw.  *I know one could mount the casper-rw file from another OS and get to the data this way but that's a hassle.


I have a valid US visa and I will be travelling from Mumbai to US via Frankfurt and Zurich. Would I need a transit visa for either?

I am travelling form Delhi (DEL) to San Francisco (SFO), I have to make a connection flight in Vienna that would take me to Frankfurt (FRA). My flight to SFO is from FRA, I have one ticket for entire journey and the flights are operated by Lufthansa or its subsidiaries.  Do I need a transit visa? My flight arrives at Vienna international airport and leaves from the same, and for second leg it arrives at Frankfurt international airport.  I asked this question as an addendum to my  but was advised to make a new post.  I hold Indian passport and valid US visa.


I am getting wrong output while using java Math functions. expected output = 4.32 present output= 4.30287105016515  double startHeight= 60.00; double initaldistance=1000.00; double speed=120; startDistance=(initaldistance-1.688*speed); startAngle = Math.toDegrees(Math.atan(startHeight/startDistance)); System.out.println(startAngle);

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


Im trying to create a triangulated .obj file with 3D text. Problem is, after creating the text I can't find a way to properly triangulate it.  Converting it to a mesh only triangualte parts of it.  Is there a simple way to do something like that?   P.S Im a complete newbie with Blender :S  Thanks

I need to create test file for my program. But it only accepts polygons with 3 vertices - triangles as input. How can I convert all polygons of some object into triangles?  I know how to select all faces, but how to split them into triangles.


(can't post pictures yet) the questionmark is a bit lower than the "Status Update" text and I want to align it, but i don't know how. The css and html is here: .qmarkCircle {   border-radius: 50%;   width: 0.8em;   height: 0.8em;   display: inline-flex;   justify-content: center;   align-items: center;   padding: 2px !important;   margin-left: 5px;   background: #fff;   border: 1px solid #666;   color: #666;   font: 0.8em Arial, sans-serif;   font-weight: bold;   box-sizing: initial;    &:hover,   &:after{     content: "?" !important;   } }
{{ 'home.status-title' | translate }}

   hope this is enough

I want to center a div vertically with CSS. I don't want tables or JavaScript, but only pure CSS. I found some solutions, but all of them are missing Internet Explorer 6 support.
Div to be aligned vertically
   How can I center a div vertically in all major browsers, including Internet Explorer 6?


I have set up a system where the player can update their scoreboard via the tellRaw command using triggers. However, whenever the player clicks on a clickEvent in the chat, the following message appears.  Trigger [nameoftrigger] (set value to #).  Is there any way I can stop this message from appearing in the chat? I don't really want the player to know what is happening "behind the curtain."

I want to make a tellraw shop but to activate command blocks I want to use /setblock command when clicked on a text. Is it possible to disable "Block placed" text showing up?


I'm trying to get IE 10 or 11 to install with wine an get stuck with either "Operating system not supported" when wine is set to vista or win 8, or "Internet Explorer needs an update before installing" Win 7. The required update appears to be Windows 7 Service Pack 1. Is there any way I can get the windows 7 in wine to service pack level 1.  I'm no fan of IE or Edge but I have an important needed program (Sabre Red) that apparently has a dependency on Internet Explorer 10 or later in order to run. This is my primary holdup to escape the MS stronghold as my primary production machine.  Thanks in advance for any help.

I am developing one site which has chat feature in Rails. I am using Ubuntu 12.04 LTS. I need to check that the site is IE9 because the chat feature using socket io of HTML5. I want to know that how to install IE9 in Ubuntu. I have looked at Chrome and Firefox extensions but if any standalone is available then please give me suggestion.


I recently found a piece of PHP code on Stack Overflow that was missing a semicolon. This would cause a syntax error, which in turn would cause a "500 internal error", and could be very confusing to beginners.  However, when I went to edit the post, I got an error:     Edits must be at least 6 characters; is there something else to improve in this post?   What is the correct way to avoid this limit, when the change to be done is genuinely less than 6 characters? (as in this case, it was a single semicolon; I ended up just commenting about it)

I recently came across an  by  which contained a link to a specification that has since been moved. When attempting to edit the link, a change which involved the subtraction of only 4 characters, I ran up against the 6 character minimum requirement.  Ordinarily this would not be an issue. A less experienced poster would likely have other things within the answer that could be changed (). In fact, this seems to be the answer on every meta post relating to this topic (, , etc...).  The problem here, since I don't have 2k reputation, is that BalusC writes excellent answers... with the reputation to back them up. I don't feel there is anything in the post (besides the link) that would benefit from me editing.  What is the standard practice here?   Flag the post and explain my situation in the notes (for someone with higher reputation)? Comment on the post and hope that a) visitors read the comments or b) the OP gets notified and updates their post? Make edits, for the sole purpose of increasing characters, providing no benefit and possibly hurting the quality of the post?   For reference, the EL Specification in the post should be changed to , if someone wants to go ahead and take care of this.


I am trying to implement a simple navigation drawer in my Android app but I am not able to solve a certain bug.   Attempting to run an app throws a NullPointerException:  Process: com.emertonalex.whiskynotes04, PID: 22225               java.lang.RuntimeException: Unable to start activity ComponentInfo{com.emertonalex.whiskynotes04/com.emertonalex.whiskynotes04.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v7.app.ActionBar.setDisplayHomeAsUpEnabled(boolean)' on a null object reference                   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2778)                   at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856)                   at android.app.ActivityThread.-wrap11(Unknown Source:0)                   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589)                   at android.os.Handler.dispatchMessage(Handler.java:106)                   at android.os.Looper.loop(Looper.java:164)                   at android.app.ActivityThread.main(ActivityThread.java:6494)                   at java.lang.reflect.Method.invoke(Native Method)                   at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)                   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)                Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v7.app.ActionBar.setDisplayHomeAsUpEnabled(boolean)' on a null object reference                   at com.emertonalex.whiskynotes04.MainActivity.setupToolbar(MainActivity.java:320)                   at com.emertonalex.whiskynotes04.MainActivity.onCreate(MainActivity.java:97)                   at android.app.Activity.performCreate(Activity.java:6999)                   at android.app.Activity.performCreate(Activity.java:6990)                   at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1214)                   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2731)                   at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856)                    at android.app.ActivityThread.-wrap11(Unknown Source:0)                    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589)                    at android.os.Handler.dispatchMessage(Handler.java:106)                    at android.os.Looper.loop(Looper.java:164)                    at android.app.ActivityThread.main(ActivityThread.java:6494)                    at java.lang.reflect.Method.invoke(Native Method)                    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)                    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)    As far as I see it the getSupportActionBar() function call that messes stuff up. I tried covering the call with the "assert" in setupToolbar() and it seems like it passes that stage and fails at the   getSupportActionBar().setDisplayHomeAsUpEnabled(true);  The pieces of code themselves that call the getSupportActionBar() are these:  In MainActivity   protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.add_notes);    ...    setupToolbar();     getSupportActionBar().setDisplayHomeAsUpEnabled(false);    getSupportActionBar().setHomeButtonEnabled(true);    ... }    And   void setupToolbar(){     Toolbar toolbar = findViewById(R.id.toolbar);     setSupportActionBar(toolbar);      assert getSupportActionBar() != null;     getSupportActionBar().setDisplayHomeAsUpEnabled(true); }   I am new to Android/Java dev and would be very appreciative of any help.  Also, it would be great if you tell me why this error appears, to begin with, so I can avoid it in the future.   Thank you

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?


I am using Ubuntu-14.04 now, and want to upgrade to Ubuntu 16.04.   It will upgrade to the newest Ubuntu-17.10, if I use the commands below:  sudo apt-get update sudo apt-get upgrade sudo apt-get dist-upgrade do-release-upgrade   Does somebody knows "how can I upgrade Ubuntu to certain version (16.04) without re-installing system?  Thanks a lot.

I like to keep all my servers running only the most stable versions of any operating system, so obviously I only run the LTS versions of Ubuntu.  I currently have a few servers running Ubuntu server 12.04 LTS. I'd like to upgrade them to 14.04. Is it safe to jump versions like that, and how can this be done?


Find all $f  \in \mathscr{C^\infty}(\mathbb R)$ that satisfy the equation   $$f'(x) = f(x+1) - f(x).$$   The 'obvious' answer is the set of all affine maps, but I'm not entirely sure.  Some progress:  For any $x \in \mathbb{R}$, we have $$f(x+h) = f(x) + f'(x)h + r(x,h),$$ where $r(x,h) = o(h)$. Letting $h = 1$, $$f(x+1) = f(x) + (f(x+1) - f(x)) + r(x,1).$$ This implies $r(x,1) = 0$ for all $x$, so the linear approximation is exact for an increment of 1.  I thought of Taylor's theorem as well. For any $x \in \mathbb R$, $$f(x+h) = f(x) + f'(x)h + \frac{f''(c)}{2}h^2$$ for some $c \in (x,x+h)$. Again letting $h = 1$ we get that $f''(c) = 0$, but that only shows that the second derivative vanishes at some point, not all points.  I have a feeling that the first proof just needs one extra step to finish the job. This problem is not for a class, so I would be interested in seeing the solutions if the $\mathscr{C}^\infty$ condition were weakened (my first proof only requires differentiability, so I would assume a proof requiring $\mathscr{C}^1$ would be on a different route).

The question is:     When $f(x+1)-f(x)=f'(x)$, what are the solutions for $f(x)$?   The most obvious solution is a linear function of the form $f(x)=ax+b$. Is this the only solution?  Edit  I should add that $f:\mathbb R\to\mathbb R$ to the question.


I have a site that displays (or that's the plan at least) content dynamically, but it has some problems. When I open the site for the first time and click on a link, it loads the content dynamically. When I go back and press a link again, it reloads the whole site. I feel like I'm missing something important, what can it be?  Ajax:  $(document).ready(function () {     var container = $('#content');      $('a').click(function (e) {         e.preventDefault();         var url = $(this).attr('href');         //$('#content').hide('fast');         history.pushState({path: url}, null, url);         container.load(url);         return false;     });      $(window).bind('popstate', function (event) {         var state = event.originalEvent.state;          if (state) {             container.load(state.path);         }     });      history.replaceState({path: window.location.href}, ''); });

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


I changed a setting on my Windows 8.1 PC and now the screen has gone black. Ive tried to get into safe mode using F8 / Shift-F8 but it never gives me safe mode.  All the guides on how to get into safe mode just state to do it through windows but as i disabled GPU Scaling on my AMD graphics card the screen is just black. I need to get into safe mode and re-enable GPU Scaling.  I've tried booting from Windows 8.1 disc and used repair PC that didn't work.  Also i tried restoring to an earlier version but that didn't work keeps saying cannot restore.  Really hope i don't have reformat the drive.  Anyone got any advice?

I have Windows 8 Enterprise x64. It's installed a virtual machine. After trying to update VMWare's guest extension it black screened. After resetting it, now the virtual machine won't boot. It just says "automatic repair couldn't repair your PC"   Everything I do ends with an error or it coming back to this screen. If I go to Troubleshoot > Advanced Options > Start up settings and then go to Safe Mode, all it will do is say "preparing automatic repair" and then "diagnosing your PC" and then will come straight back to the "automatic repair couldn't repair your PC" screen. It's as if it doesn't even attempt to go into safe made.   Is there anything else I can do before I reformat?


How can i install AMD/ATI drivers on XUbuntu 15.10? I follow this guide,  but after this i can't boot.

I am planning on doing a fresh install of Ubuntu and want to know what is the correct way to install ATI Catalyst Video Driver?      There are multiple valid answers for this question spanning over several versions of Ubuntu. For your convenience an index of each below:


I have installed Ubuntu 18.04.1 LTS, and I need to add some routes. Which command shall I use? ifup was deprecated?

I recently upgraded to ubuntu 18.04 from 16.04 and am trying to figure out how to get my ip route and ip rule commands that I used to put in /etc/network/interfaces working under netplan.  These are the commands that I'm trying to reproduce, that I previously ran in /etc/network/interfaces:  sudo ip rule add table 129 from 192.168.1.160 sudo ip route add table 129 to 204.8.230.0/24 dev enp0s3 sudo ip route add table 129 to 192.168.1.0/24 dev enp0s3 sudo ip route add table 129 default via 192.168.1.1   This is my first pass at the netplan config in /etc/netplan/01-netcfg.yaml:  # This file describes the network interfaces available on your system # For more information, see netplan(5). network:   version: 2   renderer: networkd   ethernets:     enp0s3:       dhcp4: yes       routes:         - from: 192.168.1.160           to: 204.8.230.0/24           via: 192.168.1.1         - from: 192.168.1.160           to: 192.168.1.0/24           via: 192.168.1.1   However, after a restart those routes do not show up in the ip route output. How do I get these routes to stick?  Note that I've also tried putting these commands in a script in /usr/lib/networkd-dispatcher/routable.d based on some documentation I found, but that does not appear to have worked either.  EDIT: I'm getting closer. This is the new config, but now the problem is that although the table shows up in ip rule, ip route show table 129 is empty:  # This file describes the network interfaces available on your system # For more information, see netplan(5). network:   version: 2   renderer: networkd   ethernets:     enp0s3:       dhcp4: yes       routing-policy:         - from: 192.168.1.160           table: 129       routes:         - to: 204.8.230.0/24           via: 192.168.1.1           table: 129         - to: 192.168.1.0/24           via: 192.168.1.1           table: 129         - to: 0.0.0.0/0           via: 192.168.1.1           table: 129   I'm on netplan version 0.36.1


I know there must be something unmathematical in the following but I don't know where it is: \begin{align} \sqrt{-1} &= i \\\\\ \frac1{\sqrt{-1}} &= \frac1i \\\\  \frac{\sqrt1}{\sqrt{-1}} &= \frac1i \\\\  \sqrt{\frac1{-1}} &= \frac1i \\\\  \sqrt{\frac{-1}1} &= \frac1i \\\\  \sqrt{-1} &= \frac1i \\\\  i &= \frac1i \\\\  i^2 &= 1 \\\\  -1 &= 1 \quad !!? \end{align}


I am trying to schedule a time to change the visible property of the form after 10 seconds. Task.Delay(1000).ContinueWith((task) => {      this.Visible = true; });  And I get an error like this  How can i solve it?

I have a scenario. (Windows Forms, C#, .NET)   There is a main form which hosts some user control. The user control does some heavy data operation, such that if I directly call the UserControl_Load method the UI become nonresponsive for the duration for load method execution. To overcome this I load data on different thread (trying to change existing code as little as I can)   I used a background worker thread which will be loading the data and when done will notify the application that it has done its work.   Now came a real problem. All the UI (main form and its child usercontrols) was created on the primary main thread. In the LOAD method of the usercontrol I'm fetching data based on the values of some control (like textbox) on userControl.    The pseudocode would look like this:  CODE 1  UserContrl1_LoadDataMethod() {     if (textbox1.text == "MyName") // This gives exception     {         //Load data corresponding to "MyName".         //Populate a globale variable List<string> which will be binded to grid at some later stage.     } }   The Exception it gave was     Cross-thread operation not valid: Control accessed from a thread other than the thread it was created on.   To know more about this I did some googling and a suggestion came up like using the following code  CODE 2  UserContrl1_LoadDataMethod() {     if (InvokeRequired) // Line #1     {         this.Invoke(new MethodInvoker(UserContrl1_LoadDataMethod));         return;     }      if (textbox1.text == "MyName") // Now it wont give an exception     {     //Load data correspondin to "MyName"         //Populate a globale variable List<string> which will be binded to grid at some later stage     } }   BUT BUT BUT... it seems I'm back to square one. The Application again  become nonresponsive. It seems to be due to the execution of line #1 if condition. The loading task is again done by the parent thread and not the third that I spawned.  I don't know whether I perceived this right or wrong. I'm new to threading.  How do I resolve this and also what is the effect of execution of Line#1 if block?  The situation is this: I want to load data into a global variable based on the value of a control. I don't want to change the value of a control from the child thread. I'm not going to do it ever from a child thread.   So only accessing the value so that the corresponding data can be fetched from the database.


I need to refer to school for grades 4-12, thus the usual K-12 is not suitable, and it would be ideal to do this with a word rather than the numbers "4-12". What word generically refers to the schooling associated with K-12?  I don't want to use K-12 itself because that is misleading since it implies K-3 is included, but I do want a synonym in word-form to generically refer to that entire segment of schooling as opposed to college or technical schooling.

I was creating a web form for a client who requested the highest-grade completed for primary and high school and then college.  The original paper form had the following     Circle highest grade completed 1 2 3 4 5 6 7 8 9 10 11 12 College 1 2 3 4   For the web form, I turned these into two dropdowns. Labeling College was easy, but the 1-12 was harder.  Due to space issues, I chose "Compulsory" as grades 1-12 in the US are compulsory, but my project manager felt it wasn't a layman term, so I switched it for K-12, which is what the Department of Education calls it, even though kindergarten is not included.  So, my question is, is there a one-word (or very short phrase) equivalent to Primary + High School?


I currently have one small VPS which I am using to host a Wordpress site (Nginx,PHP5,MariaDB). I have started to run into some memory issues (DB crashes) indicating it's probably time to move to a larger VPS.   I have two options:   I can upgrade the current VPS doubling it's memory. I can keep the current VPS, add a second same sized VPS, and move      MariaDB to it.   The additional costs for either option would be the same. As a rule of thumb which solution is likely to provide overall better performance and stability?  EDIT  I don't think the  is in fact duplicate. That question in very broad and is more about general solutions for capacity planning. What I'm trying to understand is the relative merits of two possible solutions and how to better evaluate between them. The specify capacity issue (memory shortage) is mostly ancillary to my question.

This is a  about  Related:      I have a question regarding capacity planning. Can the Server Fault community please help with the following:   What kind of server do I need to handle some number of users? How many users can a server with some specifications handle? Will some server configuration be fast enough for my use case? I'm building a social networking site: what kind of hardware do I need? How much bandwidth do I need for some project? How much bandwidth will some number of users use in some application?


So I got a second monitor and it's color greatly differs from my current one. The new one is a Samsung PLS monitor, the older one an ASUS model (no idea which); both have a Full HD resolution, the first one is connected over HDMI, the latter over DVI. Both are in a ~200 € price range, so no professional design monitors with fully adjustable displays.  At first sight, my old monitor looked better in comparison (much more vibrant, generally a bit brighter; also, this might have just been the force of habit). However, this one has several display modes, of which the 'scenery mode' was selected. In the 'standard mode', the overall look is much closer to the new monitor. So I'm assuming this scenery mode just adds some vibrance and similar adjustments to make the picture look better for consumers - which might not be what I want for design work.   By adjusting both monitors manually, I got both to look somewhat similar, which means less vibrance and saturation than I'm used to. However, I'm kind of confused now, I'm actually not sure if these settings are actually better for design work than the 'scenery mode' which subjectively looks better to me.  Not sure how to put it into words, but here are my questions:   Is it beneficial to adjust my two monitors so that both look roughly the same? Or should I adjust both individually so that they 'look best'? (This way, I would actually see how my design looks on different monitors, wouldn't this be beneficial at least for screen design? I don't do print design anyway ...) How do I know which settings are 'best'? I can of course adjust my old monitor to fit my new monitors appearance, but how can I know what are the correct settings - if such a thing even exists - without some kind of reference? How far can I trust my subjective perception? (I ran the 'calibrate display colour' helper provided by Windows 10 on both monitors, but that didn't help that much. I've cranked up the brightness of my new monitor, but the background of this page, for example, still looks kinda grey-ish even though it's close to white ... or that might just be my perception, because I'm used to the vibrant and brightened scenery mode of my old monitor ... I'm so confused.) I have an nVidia GTX 970. In the Control Panel's colour options, I can choose between 'Other applications control colour settings' and 'Use nVidia settings'. If I choose the latter, I can adjust Brightness, Contrast and Gamma on OS-level (as opposed to the monitor settings itself). Is that a good idea or should I always leave the other applications in control, as to not interfere with Creative Cloud Software?   Sorry I know those questions are kind of convoluted, I'm just confused because I never had a second monitor to work with and now I'm not even sure I can trust my own perception, so I have no idea how to find optimal settings ...  Thanks!

I designed a mockup on my LG monitor. When I view the same design on another monitor that I own, the colors seem drastically different. I reset both of the monitors to their factory defaults, but still the issue persists. I'm wondering if some of my clients might dislike my designs because of this. What should I do?  How can I make sure that what I design is what my client sees?  Even worse still, I've realized that my laptop is showing different colors too.