How to Label y-axis properly when plot from CSV file?

I would like labeling as follows:   It does not get proper labeling on y-axis when I am plotting data from CSV file in Latex. Here is the code :    \documentclass{standalone} \usepackage{tikz,pgfplots} \usepackage{filecontents} \pgfplotsset{compat=1.8}   \begin{document} \pgfkeys{/pgf/number format/.cd,1000 sep={\,}} \begin{tikzpicture} \begin{axis}[  %restrict x to domain=1:4, restrict y to domain=7:8, %ymax=8,ymin=7 xtick={1,2,3,4}, %ytick={7.90,7.91,...,7.99,8}, xlabel=Shares, ylabel=Entropy]   \addplot[color=red,mark=*, mark size=1.5pt] table[x=Share_No., y=Entropy_r, col sep=tab]{data.csv}; \addplot[color=green,mark=square*, mark size=1.5pt] table[x=Share_No., y=Entropy_g, col sep=tab]{data.csv}; \addplot[color=blue,mark=triangle*, mark size=1.5pt] table[x=Share_No., y=Entropy_b, col sep=tab]{data.csv}; \legend{red,green, blue}  \end{axis}   \end{tikzpicture} \end{document}   and the CSV file :    Share_No.   Entropy_r   Entropy_g   Entropy_b 1   7.9981486429    7.99831760161   7.99844751811 2   7.99870797699   7.99858499663   7.99867850346 3   7.99883018839   7.99864575932   7.99835839694 4   7.99851352793   7.99834080804   7.99864899695   It produces the following graph:      How can I fix this?  Updated: The answer in the given link is not working for me.  Here are the modified codes:    \documentclass{standalone} \usepackage{tikz,pgfplots} \usepackage{filecontents} \pgfplotsset{compat=1.8}   \begin{document} \pgfkeys{/pgf/number format/.cd,1000 sep={\,}} \begin{tikzpicture} \begin{axis}[      y tick label style={     /pgf/number format/.cd,     fixed,     fixed zerofill,     precision=1,     /tikz/.cd },  %restrict x to domain=1:4, %restrict y to domain=7:8, %ymax=8,ymin=7 xtick={1,2,3,4}, %ytick={7.90,7.91,...,7.99,8}, xlabel=Shares, ylabel=Entropy]  \addplot[color=red,mark=*, mark size=1.5pt] table[x=Share_No., y=Entropy_r, col sep=tab]{data.csv}; \addplot[color=green,mark=square*, mark size=1.5pt] table[x=Share_No., y=Entropy_g, col sep=tab]{data.csv}; \addplot[color=blue,mark=triangle*, mark size=1.5pt] table[x=Share_No., y=Entropy_b, col sep=tab]{data.csv}; \legend{red,green, blue}  \end{axis}   \end{tikzpicture} \end{document}


I have looked through some of the previous questions posted on this topic, and I think mine is different.   Is there a flaw in defining division by zero? For example, define   $\frac{a}{0} = \infty_a$   it would seem like things work now, for example,   $\frac{a/0}{b/0}=\frac{\infty_a}{\infty_b}=a/b$.   What could go wrong with this idea, or more specifically, is it defined in some branch of mathematics?


I have a mixture data. I used EM to estimate the model parameters. When I calculate  the log likelihood function, I found that the values is positive. So, is that ok. Can the log likelihood function be positive?   To be more clear:  $ll = \sum_{n=1}^{N}\log(\sum_{k=1}^{K} \pi_{k} f(x_n;\theta_{k}))$


sys.dm_db_index_physical_stats is extremly slow

I have a database that is around 4.5TB, since we have parallel inserts (to reduce daily load time) on one table (partitioned by month) the clustered index on this table tends to be heavily fragmented. When I do a select from sys.dm_db_index_physical_stats (Limited) on this table it takes ages (> 4-5 hours). Is there a faster and better way to check the fragmentation levels on the partitions of this table, the current time this takes is completely inacceptable.


I'm trying to make a systemd timer that runs every 15 minutes. Right now I have:     timer-fifteen.timer:  [Unit] Description=15min timer  [Timer] OnBootSec=0min OnCalendar=*:*:0,15,30,45 Unit=timer-fifteen.target  [Install] WantedBy=basic.target    timer-fifteen.target:  [Unit] Description=15min Timer Target StopWhenUnneeded=yes    This runs over and over again without stopping. Does it need to be *:0,15,30,45:* instead? How can I make this work?


JQuery $.click/$.on("click") not working with $.GET/$.POST Returned HTML

I am using jQuery $.GET to scrape the search results from a remote server application and I want to have the links that are returned trigger another jquery $.GET request once they are clicked.   In the example below I am simply trying to prevent the link from opening the page and even the event.preventDefault() method is failing.  The problem is that I neither the .click() or .on("click") event handlers are firing in the example page.  Granted I am having to use CORS extension to develop this locally in Chrome but I couldn't find where that would prevent the .click events.  I've also tried using $.POST as well with no successs.  I've been at this for a bit and have googled quite a bit looking for a reasonable explanation as to why this isn't happening.  search.html  <form action="search.html" method = "post" id="searchForm"> <input type="input" name="q" id="q" /> <input type="submit" value="Search K-Tube" id="submitForm" />  </form>

             ktube.js   $("document").ready(function () {   $('a [id^="tubeLink"]').on("click", function (event) {    event.preventDefault();   });    $("#searchForm").submit( function (event) {     event.preventDefault();      var q = $("#q").val();      if (q != "") {        $.get("http://ktube.kellerisd.net/education-center?search=" + q + "&global_search=true", function(data) {                  var count=0;                 var thumbs = $(data).find(".thumbDescription h5"); //Finds the Video Thumbnails Titles                   var output = "
Results

";                  $(thumbs).each(function(index, value){                  var link = $(this).find("a").attr("target", "_blank"); //Finds the links and opens them in new browser window                 link = $(link).attr("href", "http://ktube.kellerisd.net" + (link).attr("href")); // Creates an absolute URL for Video on Ktube                 link = $(link).attr("id", "tubeLink" + index);                  output += "
"+ $(this).html(); +"
";                 count++;                 });                  output += "

Total Results: " + count;                   $("#response").html(output);          });    }else {     alert("Please enter a search term");    }      });   });


Find All Entire Functions that Takes Values Only in the Upper Half Plane.

I am working on a question stating that      Find all entire functions that takes values only in the upper half plane.   A similar (but not closely similar) question is the part (b) of this post: . However, part (b) only asks to find one entire function that takes real values onto the imaginary axis.   So here is what I attempted:   Let's denote the entire function that takes values only in the upper half plane to be $f(z)$. Then, we have $$f:\mathbb{C}\longrightarrow\mathbb{H}.$$  Since $f$ could take any complex numbers to the upper half plane, the first thing that came to my mind was to use conformal mapping to conjugate $f$ so that we have a automorphism of the unit disc $\mathbb{D}$, and we know that what $Aut(\mathbb{D})$ has a common form, so that we can solve the formula for $f$.   i.e. we have the conformal mappings $$F:\mathbb{H}\longrightarrow\mathbb{D},\ \text{by}\ z\mapsto F(z):=\dfrac{i-z}{i+z},$$ and $$F^{-1}:\mathbb{D}\longrightarrow\mathbb{H},\ \text{by}\ z\mapsto F^{-1}(z):=i\dfrac{1-z}{1+z}.$$  Thus, we have $$F^{-1}\circ f\circ F:\mathbb{D}\longrightarrow\mathbb{D},$$ so that $$F^{-1}\circ f\circ F=e^{i\theta}\dfrac{\alpha-z}{1-\overline{\alpha}z},\ \text{for some}\ \alpha\in\mathbb{C}\ \text{and}\ |\alpha|<1.$$  We then can solve for $f$: $$F^{-1}\circ f\circ F(z)=F^{-1}\circ f\Big(\dfrac{i-z}{i+z}\Big)=i\dfrac{1-f\Big(\dfrac{i-z}{i+z}\Big)}{1+f\Big(\dfrac{i-z}{i+z}\Big)}=e^{i\theta}\dfrac{\alpha-z}{1-\overline{\alpha}z}.$$  We then can replace $w:=\dfrac{i-z}{i+z}$ to solve for $f(w)$.   However, we then have two problems here:   Firstly, $w$ cannot be continuously defined when $z\rightarrow -i$.  Secondly, the final formula was really a mess.  I think the problem here is that when I did the conjugation, I actually restrict the domain of $f$ from $\mathbb{C}$ to $\mathbb{D}$. However, I do not know if there is another way to do it, I believe there is one though.  I think there must be a much more straightforward method for this question.  Thank you!


Can I enter France via Switzerland (and then get a cab to France) on the Schengen visa?

I got a Schengen visa from the French Embassy, and I'm traveling to Annecy (France) for training. Is it possible to land 1st in Geneva (the nearest international airport) and then take a cab to enter France? My training venue is nearest to Geneva. I am from non-EU countries.


Empty PostGIS geometry displaying correctly in QGIS

On a table, with pgadmin (III) I see just emptiness in the geometry column of a table, while the layer is displaying properly in QGIS (2.14). Any idea on why and how to display the geometry in pgadmin ?


I have a password secured mariadb server on an Ubuntu 18.04 server.  I can log in at the command line using  mysql -u root -p with my password.  But when I go to ` I can not log in as root.  This is the error I see:  #1698 - Access denied for user 'root'@'localhost'    mysqli_real_connect(): (HY000/1698): Access denied for user 'root'@'localhost'   I am definitely using the same password I use on the command line.  I can log in as user phpmyadmin with the password I entered during dpkg-reconfigure phpmyadmin.


Evaluating $\int_{0}^{1}\frac{1-x}{1+x}\frac{\mathrm dx}{\ln x}$

Some time ago I came across  to the following integral:    $$I=\int_{0}^{1}\frac{1-x}{1+x}\frac{\mathrm dx}{\ln x}$$ What are the hints on how to compute this integral?


I have this CSV with this format, I need to split in 16 Parts, according with the text's:  "MY TEXT","EVER, OK",,,,,,,,,,"The, CARLO","DO","ALFA","OME, GA",,   I have this way, but when appear case's with commas inside "OME, GA" doesn't work.  String[] lineToMap = line.split(",");   How I can control this cases?  Solution  I discovered this library: OPEN CSV, in my Test's work very well, but I have a problem with the codification (strange symbols like � instead ü), with characters like ü, ö, etc.. I'm using languages like German and French. I was testing with UTF-8 but didn't work, Any idea to fix this?  CSVReader reader=new CSVReader(new InputStreamReader(new FileInputStream("data/test.csv"), "UTF-8"),                  ',', '"', 0);          //Read CSV line by line and use the string array as you want           String[] nextLine;           try {             while ((nextLine = reader.readNext()) != null) {                  if (nextLine != null) {                     for (String element : nextLine) {                         System.out.println(element);                     }                                     }                }         } catch (IOException e) {             // TODO Auto-generated catch block             e.printStackTrace();         }


I have data from three different groups (n=67, 28, 25).  Can I use ANOVA to compare them or is the first group size too large relative to the size of the other two groups?  I have seen lots of texts that say the groups need to be of equal size but I have seen some suggestions that if the groups size are within a 1:3 ratio (smallest group size to largest group size) ANOVA can be applied.


I have this code, which supposed to retrieve data from CSV file, the file (set of files) structure is as following: [Mary, 7, 17] but the columns are not titled, so I only got A, B, C when I run the code I seem to have only the first result in the column. can anybody help me to iterate throw all records? public void searchFiles()     {                 int count = 0;         DirectoryResource c = new DirectoryResource();         int summ = 0;         int currentrow = 0;         String name = "ff";         String k = "Susan";         for(File f : c.selectedFiles())         {             FileResource fr = new FileResource(f);             CSVParser currentFile = fr.getCSVParser(false);             currentrow = 0;             for (CSVRecord row : currentFile)             {                 currentrow++;                 name = row.get(0);                 if(row.get(0) == k)                 {                     count++;                     summ = summ + currentrow;                     System.out.println("Row is : " + row.getRecordNumber() + " / " + currentrow);                     break;                 }                 else                 {                                         System.out.println("found");                 }             }                         System.out.println(count + " / " + currentrow + " / " + name);         }                 System.out.println("count is: " + count);         System.out.println("Summ is: " + summ);         System.out.println("Avg is: " + (summ / count));     }


How many people would like to see their favorite site with a Windows 8.1 Live Tile?   I know I would.  <?xml version="1.0" encoding="utf-8"?> <browserconfig>     <msapplication>         <tile>             <square70x70logo src="tiny.png"/>             <square150x150logo src="square.png"/>             <wide310x150logo src="wide.png"/>             <square310x310logo src="large.png"/>             <TileColor>#000000</TileColor>         </tile>         <notification>             <polling-uri src="http://notifications.buildmypinnedsite.com/?feed=http://stackoverflow.com/feeds&amp;id=1"/>             <polling-uri2 src="http://notifications.buildmypinnedsite.com/?feed=http://stackoverflow.com/feeds&amp;id=2"/>             <polling-uri3 src="http://notifications.buildmypinnedsite.com/?feed=http://stackoverflow.com/feeds&amp;id=3"/>             <polling-uri4 src="http://notifications.buildmypinnedsite.com/?feed=http://stackoverflow.com/feeds&amp;id=4"/>             <polling-uri5 src="http://notifications.buildmypinnedsite.com/?feed=http://stackoverflow.com/feeds&amp;id=5"/>             <frequency>30</frequency>             <cycle>1</cycle>         </notification>     </msapplication> </browserconfig>


Aligning values to columns after using siunitx

based on the  discussion, I made the following table:  \documentclass{article} \usepackage{siunitx} \usepackage{booktabs} \usepackage{caption}   \begin{document}  \begin{table}[ht] \centering\setlength\extrarowheight{2pt} \caption{Mean by Year and Group} \begin{tabular}{@{\extracolsep{4pt}}llc*{2}{S@{\enspace}S@{\enspace}S}} \toprule    {} & {} & {Sample} & \multicolumn{3}{c}{Median}  & \multicolumn{3}   {c}{SD}\\ \cmidrule(lr){3-3}  \cmidrule(lr){4-6}  \cmidrule(lr){7-9}  Year & Group & N & V1 & V2 & V3 & V1 & V2 & V3 \\  \midrule    2012  & Control & 2 & 10.052 & 0.294 & 10000.115 & 0.04 & 0.619 & 0.611 \\           & Treat & 2 & 0.511 & 0.083 & 0.123 & 0.573 & 0.541 & 0.734 \\     2016  & Control & 3 & 0.320 & 0.344 & 0.382 & 0.382 & 0.494 & 0.477 \\           & Treat & 3 & 0.378 & 0.296 & 0.123 & 0.386 & 0.668 & 0.732 \\  \bottomrule \end{tabular} \end{table} \end{document}   Can someone help me make the V1, V2and V3 columns be aligned to the values on each column? I mean, after using siunitx package the column titles are aligned to the beggining of the number and not to its center.


This question came just out of curiosity to know our friend the Stack Trace a little better.  As a C# (.NET) developer every one must have seen a yellow stack trace like the one below.    Most of the things in it are easily understood like the message Attempt to divide by zero and the method where it occur Page_Load even the path of the .cs file also. But after 3 years of experience the thing I still don't know is what those numbers with + sign at the end of methods denote in here, like +51, +92, +54 and +772.  Does anybody know what these are?


Unable to grant access to a chatroom to a low reputation user (trying to move a question discussion to chat)

I'd like to move the discussion from  into a chatroom. I created a chatroom (in "Gallery" mode), and under the "Access" tab is a section labelled "Explicit write access", which says:  Even when this room is read-only or their reputation is too low, these users will be able to talk in this room.  Which sounds like exactly what I want, because the user asking the question has a reputation of 5. Unfortunately, if I try to grant the user write access to the room, I get the "Users must have at least 20 reputation to talk" error. ...which I knew, and is why I'm trying to grant explicit write access because "their reputation is too low". Is there no way to have a conversation with a low-reputation user outside of comments?


Why does shutdown from a remote terminal fail to power off my machine?

I have noticed that if I shutdown Ubuntu 14.04 from a remote terminal via ssh and running sudo shutdown now, the machine does not power off.  If I use the GUI (shut down using Unity on the machine itself) then the machine does power off.  If I look on the console of the machine after issuing the remote shutdown, there are messages relating to modem manager which seems to keep restarting.  Is this a known issue?     Please note this is not a duplicate of  as I'm using ssh to connect.


Bar graph swallowing one group of entries

If followed an example from  for a simple bar graph.  \begin{tikzpicture} \begin{axis}[     x tick label style={         /pgf/number format/1000 sep=},     ylabel=Year,     enlargelimits=0.05,     legend style={at={(0.5,-0.1)},     anchor=north,legend columns=-1},     ybar interval=0.7, ] \addplot      coordinates {(2012,408184) (2011,408348)          (2010,414870) (2009,412156) (2008,415 838)}; % 2008 coordinate given, but does not show \addplot      coordinates {(2012,388950) (2011,393007)          (2010,398449) (2009,395972) (2008,398866)}; % same here \legend{Men,Women} \end{axis} \end{tikzpicture}   This plots fairly nicely (as one can see on the website too). After copying and adjusting it to my needs, I realized that it swallows the last coordinate.  This seems curious to me. Is this intended? If not, how to fix this properly (i.e. not adding a dummy coordinate)?


Can't delete question filters; fails silently

I use  so I can see every question asked about Clojure across the network.  Somehow though, I accidentally managed to create some empty filters:    , and I'm unable to delete them by clicking "delete this filter". If I try to delete them, the screen reloads, but the filter isn't deleted.  The odd thing is though, if I rename the filter, the renaming works. If I then try to delete it though, the name just goes back to what it was.  The only thing I can think of is somehow I created a ton of filters accidentally and it's only showing 4 at a time, sorted by the original name. I've tried deleting a ton though, and still haven't exhausted them if that's the case.  Note a big deal, but something seems to be bugged. Either the filters aren't being able to be deleted for some reason, or I somehow created a massive number of filters (I've never sat there and created a ton manually though, so that seems like it would be a bug, if anything).    To clarify, I'm not getting an error, it's just silently failing. I don't think this is a dupe unless the general consensus is just that the "delete" feature is inherently broken and particular way it's broken doesn't matter.


On careers replies have the option of not willing to re-locate

On the Careers site when you receive a message and reply with no interested option can "not willing to re-locate" be added as an option.  I ask as 90% of message I have to enter this response. I understand this is currently covered by this position is not quite what I am looking for however I feel it would give more feedback to employers.


Could someone do a brief example, and source of matrix multiplication with the given context?

I would like to see how this context of matrix multiplication is played out in Differential Equations. I am starting Linear Systems, and what is a tripping up factor is the matrix multiplication. Could someone recommend a source or illustrate how to multiply matrices because the linear algebra book I have does it using a calculator, and numbers; however, I am dealing with functions?  \begin{align}\frac{d}{dt}\begin{pmatrix}5e^t\cos(t)\\ e^t(3\cos(t)-\sin(t))\end{pmatrix}&=\begin{pmatrix}-2 & 5\\-2&4\end{pmatrix}\begin{pmatrix}5\cos (t)\\ 3\cos(t)-\sin(t)\end{pmatrix}e^t\end{align}


Is there a pattern to expression for the nested sums of the first $n$ terms of an expression?

Apologies for the confusing title but I couldn't think of a better way to phrase it. What I'm talking about is this:  $$ \sum_{i=1}^n \;i = \frac{1}{2}n \left(n+1\right)$$ $$ \sum_{i=1}^n \; \frac{1}{2}i\left(i+1\right) = \frac{1}{6}n\left(n+1\right)\left(n+2\right) $$ $$ \sum_{i=1}^n \; \frac{1}{6}i\left(i+1\right)\left(i+2\right) = \frac{1}{24}n\left(n+1\right)\left(n+2\right)\left(n+3\right) $$  We see that this seems to indicate:  $$ \sum_{n_m=1}^{n}\sum_{n_{m-1}=1}^{n_m}\ldots \sum_{n_1=1}^{n_2} \; n_1 = \frac{1}{m!}\prod_{k = 0}^{m}(n+k) $$  Is this a known result? If so how would you go about proving it? I have tried a few inductive arguments but because I couldn't express the intermediate expressions nicely, I didn't really get anywhere.


Let $E=\{f(x) \in L^{2}\mathbb(R)| f'(x)\in L^{2}\mathbb(R)\}$ show that differential operator is not bounded in $E$. I'm thinking in a counterexample but I can't find one. Can you find some function? The standar norm is \begin{eqnarray*} \| f\|=\sqrt{\int_{-\infty}^{\infty}|f(x)|^{2}dx} \end{eqnarray*}


Regarding Superclass variable referencing subclass object in Java

Java Inheritance: Question regarding the parent reference variable.  I am learning Java and going through the inheritance problems in Java, have one question here.  public class Shape {     private String shapeName;     private String area;     //normal getters and setters }  public class Triangle extends Shape {     private String typeOfTriangle;     //normal getter and setter. }  public class ShaperRunner {     public static void main(String[] args) {         Shape shape = new Triangle();         // Here the shape reference variable referencing to Triangle object is allowed, however using this shape object. I cannot call         shape.setTypeOfTriangle("Scalence")         System.out.println("The shape of the triangle is " + shape.getTypeOfTriangle());     } }   My Question is if shape reference variable can be used to call only the getters and setters confined to what is defined in it, then why do we even consider using shape object to reference Triangle object. I have seen such code in few places but could not understand what is the advantange of doing it.


probability of three random points inside a circle forming a right angle triangle

three points are randomly chosen on a circle. what the probability that  1.triangle formed is right angled triangle.  2.triangle formed is acute angled triangle.  3.triangle formed is obtuse angled triangle.


How can I tell what are the maximum attribute values that are expected from the different item levels? Is there a Diablo III items prefixes and suffixes list?


Can I erase my preinstalled Windows and use the serial number elsewhere?

I have recently purchased a Windows laptop with the intention of installing Linux on it.  My question is about the existing Windows installation (note that as an ultrabook, my shiny new computer does not have a CD drive, so I don't know what the recovery media is).    I would rather not dual boot, but will have occasional reasons to use Windows, so I see 2 options, both of which involve a VM:   Use a VM to point to the Windows partition . Install Linux as the only OS and then install Windows as a guest in e.g. VirtualBox.   I can see how to do #1 (and I can also see some of the potential problems that will come from multiple OSes reading the same partition).    About #2: if I completely wipe the HDD and install Linux only, can I use the Windows serial # to install a copy of Windows (8.1 to be specific) as a VM?  Or will I have some issue, even though it is a legitimate serial #?


My terminal doesn't work. How can I fix it?

When I open terminal, the start text like:  maryam@laptop: $   doesn't appear in the first line of terminal. Also any command like cd or ls doesn't work. I can't do anything in my terminal.  How can I fix it?


Defining a standard folder for image resources

how can I define a command so that in the preamble of my document I can have something like  \FigureFolder{name}   So that the following two commands will work  \newcommand{\FigureCaption}[3]{\begin{figure}[h!]\centering\includegraphics[scale=#1]{FIGURES/\FigureFolder/#2}\caption{#3}\label{#2}\end{figure}}  \newcommand{\FigureNoCaption}[2]{\begin{figure}[h!]\centering\includegraphics[scale=#1]{FIGURES/\FigureFolder/#2}\label{#2}\end{figure}}   Basically I want to associate with every of my LaTeX files a separate figure folder (to keep things a bit organised), and specify the name of that folder at the beginning of the document. Of course, I know I could just copy the \newcommand codes in the preamble but I prefer to put those commands in a .sty file and not have too many things at the top of my document.


Do you go through customs when returning to your country if you never entered any others (by sea)?

For example, if I as a Canadian took a sail boat with infinite supplies, left Halifax, NS and did a giant loop of the Atlantic Ocean never getting within 200 NM of any other country (thereby leaving both  and the ), do I have to report to Canada Border Services Agency upon returning to Canada?


Using Array.prototype.find() to check existence and return a boolean

I'm trying to check for the existence of a site in my siteList. I'm getting this data from the command line and I'm trying to make sure the user inputs a site that is in the list, if they don't, they get a usagePrompt()  This is the site list  var siteList = [     { site: 'github', password: null },     { site: 'stackoverflow', password: null } ]   This is the if statement it's going in  if (!process.argv[2] || !process.argv[3] || /* PROBLEM */)) {     usagePrompt() }   And this is my /* PROBLEM */ check that I'm going to replace the comment with.  console.log(typeof(siteList.find(site => site.site == process.argv[2]) != 'undefined'))   I want to .find() the site, and if it exists it should therefore not be undefined - but this just returns boolean, which exists and is true in the if statement regardless of whether the site is in the list.


How to trim whitespace from a Bash variable?

I have a shell script with this code:  var=`hg st -R "$path"` if [ -n "$var" ]; then     echo $var fi   But the conditional code always executes, because hg st always prints at least one newline character.   Is there a simple way to strip whitespace from $var (like trim() in )?   or   Is there a standard way of dealing with this issue?   I could use  or , but I'd like to think there is a more elegant solution to this problem.


Here is how I tried solving this problem:  $\cos{z} = \frac{e^{iz}+e^{-iz}}{2} = -2 \Leftrightarrow e^{iz}+e^{-iz} = -4$  Multiply by $e^{iz}$:  $e^{2iz} + 1 = -4e^{iz} \Leftrightarrow e^{2iz}+4e^{iz} + 1 = 0$  Substitute $e^{iz}$ with $x$ and solve for $x$:  $x^2 - 4x + 1 = 0 \Rightarrow x = 2 \pm\sqrt{3}$  Substitute back and solve for $z$:  $e^{iz} = 2\pm\sqrt{3} \Leftrightarrow iz = 2\pi ni + \log(2\pm\sqrt{3}) \Leftrightarrow z = 2\pi n -i\log(2\pm\sqrt{3})$  Answer: $z = 2\pi n -i\log(2\pm\sqrt{3})$ (for $n\in\mathbb{Z}$)  Now I am unsure about the period, some resources say that it should be $2\pi n$, and some say it should be $2\pi n + \pi$. How do I know? I did this how I have learned to do it, but am I doing it wrong?


Need to grant two users to an AIX server to just one folder

Ok, in our environment, most users (including myself as one of the unix admins) don't actually have admin rights directly on the aix servers.  We login to a front unix server as ourselves without root access.  Then we run a command that logs us in as the actual root user but everything we do is logged to a text file, so if we really screw something up, there are logs to point fingers at who did it.  I can't login directly to the unix servers.  I don't have access.  I have to login to the logging server, then ssh to the server as direct root.  Well, I have a request right now that two users that know absolutely nothing about how to navigate a unix command prompt needs access to some log files 3 folders deep.    We're going to make it so they're going to log directly into the unix box with the log files, so they don't go through the server that logs all their command history.  But our plan is to create them as basic users with no administrative access.  Then they're actually going to access the files using a GUI utility to just copy and paste the files to their Windows machines.  The permissions on this server without making any modifications look like this already...  parent folder drwxrwxrwx  sub folder drwxrwxr-x  log folder drwxr-xr-x  log files -rw-rw-r--  So, if I create two users on the box and make them part of no security groups, they should already be able to navigate down to the folder no problem because everyone has read access down to the log files.  But, what we want is something super simple for these two non-unix experienced users.  I've been working this job as a unix admin for about 3 months.  I've taken a lot of unix classes but most of my professional experience is in Windows servers.  I know in a Windows environment, I'd just share out the logs folder.  The user, if wanted to experiment, might notice they could access the parent folder, but probably wouldn't know enough to try it.    Is there a way in an AIX unix environment to just somehow share the logs folder out so the users don't have to drill down to the logs folder and possibly get lost or access something they shouldn't access?  I'm not changing the permissions.  I've been working for this company for 3 months and a multi-million dollar enterprise doesn't like me telling them what they've been doing for the last 20 years is wrong and they should change it.  So, I have to make work what they already have in place.


What happens when the frequency of A.C becomes infinite?

In an alternating current, the flow of electric charge periodically reverses direction, and the number of times it does that is called the frequency of the current. However, if the frequency of an AC is made infinite, would any current flow? I asked this question to my school teacher and he was unable to provide me with an answer unfortunately.  If I consider a horizontal wire, through which an AC is flowing, then I can say that an electron in the wire is moving 50 times left and 50 times right, if the frequency is assumed to be 50Hz. It seems to me that if I increase the frequency, the displacement of the electrons in both the directions, that is left and right, will gradually decrease, and finally become 0, when frequency is infinite, thus making I = 0.  What have I got wrong?


I unlock Files from the  Unity launcher.  I don't find a way to lock it back because when I open a new Files window the icon does not appear inside the launcher.  I am running Ubuntu 13.04 (Raring Ringtail) 64-bit.  Thank you for your help.


After upgrading to 12.04 from 10.04, can't login to PHPMYADMIN

I just can't login to PhpMyAdmin anymore, it says bad logins. PHP works perfectly. Please help. Thank you.  2002 Cannot log in to the MySQL server Language Log in Username: Password:  Connection for controluser as defined in your configuration failed.


Generalizing quantum teleportation for qudits

In  to a previous question, , Craig Gidney states:     The more complicated way to generalize teleportation is figuring out how to make it work on qutrits and qudits instead of only qubits. Basically, instead of using a "basis" made up of tensor products of X and Z matrices, you need to switch to a basis based on .   How can quantum teleportation be generalized for qudits?


In a circuit, do surface charges get influenced by external electric fields?

Hello ,This image represents surface charges in a circuit caused by the battery's electric field, if you were to place an other electric field source of the same magnitude (but not connecting it to the circuit (on top of the battery or under it)) and placing so it has the same direction of the battery's electric field for me it would do 2 things :  First, since they are in the same direction their power will add up resulting in a doubled potential difference (e.g voltage) (well not totally since the distance at least a bit more), this will translate to the surfaces charges as a double of their density everywhere to maintain the same electric field inside the wire.  Second, The battery will get used more quickly due to the higher current.  However I know that this is wrong because :   This requires if I place the other electric field source to counter act the electric field of the battery, or if the other electric field is stronger will imply many weird reactions(after thinking about it you need a really strong second battery) .  The evenements I describe don't seem to really happen in the real life,  So if someone could show me the error in my reasoning,Thanks. TLDR: In a circuit why dosen't the electric field of other external things even help a tiny bit when stacking with the battery's electric field.


Existence of antiderivative of a function

Let $f: \mathbb{R}\rightarrow{\mathbb{R}}$ be given by $f(x)=sen(\frac{1}{x})$ si $x\neq 0$ and $f(x)=c$ si $x=0$, where $c\in [-1,1]$  For which values of c there is an antiderivative?  Proof (attempt): I want to use a proposition: $f$ is continuous if, and only if, $osc(\Omega)=0$, because $f$ is discontinuous at all points $c\in [-1,1]$.


How to save installer file while downloading from ubuntu software center?

Can anyone tell me (if this is possible) how can I save the installer file of a software which I download via Ubuntu software center... I'm new to Ubuntu so give me answer that is understood by me.


Adding complex phonetic symbols to LaTeX

I am trying to add symbols from the International Phonetic Alphabet to my thesis. For some of the characters, I have no idea how to add them to TeX.    The retroflex is giving me troubles.   \documentclass{article}  \usepackage{tipa} \begin{document}     \begin{tabular}{llllllll}     ~                   & Labial & Dental & Alveolar & Retroflex & Palatal & Velar & Glottal \\     Stop                & ~      & ~      & ~        & ~         & ~       & ~     & ~       \\     Voiceless           & ~      & ~      & ~        & ~         & ~       & ~     & ~       \\     Voiceless aspirated & ~      & ~      & ~        & ~         & ~       & ~     & ~       \\     Voiced              & ~      & ~      & ~        & ~         & ~       & ~     & ~       \\     Voiced aspirated    & \textipa{}     & ~      & ~        & ~         & ~       & ~     & ~       \\     Fricative           & \textipa{}    & ~      & ~        & ~         & ~       & ~     & ~       \\     Nasal               & t͡ʃʰ    & ~      & ~        & ~         & ~       & ~     & ~       \\     \end{tabular} \end{document}   Can anyone tell me how to add retroflex symbols in LaTeX?  The description of the symbols can be found .  UPDATE: I have added the symbols t͡ʃʰ and n̪. XeLaTeX is not printing them.


I have fluid simulation with an inflow object. I want the inflow to go for 2 seconds, then have the inflow stop (so no more fluid is added) but keep the simulation going  (so the existing fluid sloshes around).  However, I do not see any way to set start and ending values on my inflow object.  How do I stop inflow at a certain frame/time in my simulation?


i have this button inside a popup.(in a javascript file)  '
'+     '<button class="btn btn-primary" >this</button>'+     '
'+   and i am accessing this in function  $('.thisdiv').on('click', function (e) {        $('.overlay').hide();          $('body').removeClass('overflow');      });   this is basically supposed to be a button which, when clicked, closes the pop up. (the simple cross button) but it does not work. it does not go into the function, i was told to use delegates. but shouldn't this be the simpler method? what am i missing?


How long time does it take to TRUNCATE 50 million rows?

I want to TRUNCATE (or remove all rows in) a table with 50 million rows.  The database is in use in production.  How long time will the TRUNCATE operation take?


Looking for a decent alternative to the DDI Builder, ideally a free browser version. Currently using  and it's decent, but I'm just a guy that likes options.  I've seen a , but it's 2yrs old. I looked at a few of the options but found mostly PDF stuff. Currently playing on roll20, so I like the idea of being able to share a link back and forth with the DM.  Thanks.


Can I delete all materials of all objects in a scene quickly?

Is there a quick way to delete all materials in the scene? I have a scene containing 20+ materials and all linked to objects. I'd like to remove all the materials from my blender file.


Show there doesn’t exist a non-constant polynomial $p(x)$ with integer coefficients such that $p(x)$ is prime for all non-negative integers $n$.   There is a hint: note in particular that $p(0)$, the constant term of $p(x)$, is prime.


Polynomial ring with isomorphic quotients

If $R$ is a commutative ring and $f(x), g(x) \in R[x]$ two polynomials such that $R[x]/f(x)\cong R[x]/g(x)$ as $R$-algebras, what can we say about $f$ and $g$?   Or given $f(x)\in R[x]$, what can we say about the set $\{g \in R[x]\mid R[x]/f(x) \cong R[x]/g(x)\}$?  Can we conclude that $\mathrm{deg}(f) = \mathrm{deg}(g)$? Is there an automorphism of $R[x]$ taking $f$ to $g$?  I'm most concerned about the cases where $R=k$ is a field, $R=\mathbb{Z}$, or $R=\mathcal{O}_k$ is the ring of integers of a number field, but I'd be interested in the most general results possible.


Can FFMPEG extract images from a video with timestamps?

I'm trying to extract frames from a video  and get the exact timestamps of each frame extracted (on a picture).  To extract frames from video without timestamps I use this syntax:  ffmpeg -i video.wmv -r 0.08 -f image2 -s 512x384 video2%%4d.jpg


How to use multibib in order to insert a second bibliography as a part of an annex?

I’m currently using apacite for my thesis and I would like to use multibib in order to have two separate bibliographies. How can I do that ?  This a MWE :  \documentclass[12pt,a4paper,twoside=semi,footinclude=true,headinclude=true]{scrbook} \usepackage[parts,pdfspacing,dottedtoc]{classicthesis} \usepackage[numberedbib,nosectionbib]{apacite} \usepackage{hyperref} \begin{document}  \backmatter \section{Conclusion générale} \bibnewpage  \nocite{*} {\raggedright  \bibliographystyle{apacite}  \bibliography{mabiblio}} \end{document}


Set organization wide email in scratch org?

When trying to deploy an auto responder rule to a new scratch org, we're getting:     [email] is an invalid From email address.: Email Address   Is there a scratch org config to set an organization wide email? Surprisingly I haven't found any resources about this specific question.


How to get all the matches from a file based on names in another file?


Is "The empty set is a subset of any set" a convention?

Recently I learned that for any set A, we have $\varnothing\subset A$.  I found some explanation of why it holds.     $\varnothing\subset A$ means "for every object $x$, if $x$ belongs to the empty set, then $x$ also belongs to the set A". This is a vacuous truth, because the antecedent ($x$ belongs to the empty set) could never be true, so the conclusion always holds ($x$ also belongs to the set A). So $\varnothing\subset A$ holds.   What confused me was that, the following expression was also a vacuous truth.     For every object  $x$, if $x$ belongs to the empty set, then $x$ doesn't belong to the set A.   According to the definition of the vacuous truth, the conclusion ($x$ doesn't belong to the set A) holds, so $\varnothing\not\subset A$ would be true, too.  Which one is correct? Or is it just a convention to let $\varnothing\subset A$?


An example would be "It flew over everyone's heads", or "It flew over everyone's head".  What would be correct in this case and why?


Theoretical/ Dimensional Analysis Question

Position is the integral of velocity.  However, position and velocity have different dimensions. How is this difference consistent with the conclusion that the integration sign is dimensionless?


Suppose $f$ is differentiable at $0$ and $f(0)=0$. Prove that there exist some function $g(x)$ such that $f(x)=xg(x)$ and $g$ is continuous at $0$.  I think I am on the right track, here:  If I write $g(x)=\frac{f(x)}{x}$ then $g$ will be discontinuous at $0$ because $f(0)=0$. Now, as an example, let $f(x)=x^2$ and $g(x)=x$. How can I proceed?


What is the likelihood of ever discovering the graviton?

How would one look for and confirm existence of a graviton?  Someone was speaking to me about perhaps one day discovering the graviton, but to me it seems unlikely, although I'm young and essentially quite naive, so am coming to you physicists to ask    What actually is the likelihood of finding it?  How would we find it?


Let $f,g$ be continuous from $\mathbb R$ to $\mathbb R$

Let $f, g$ be continuous from $\mathbb R$ to $\mathbb R$, and suppose that $f(r) = g(r)$ for all rational numbers $r$. Is it true that $f(x) = g(x)$ for all $x \in \mathbb R$?


Find all primes $p$ and $q$ such that $pq\mid 2^p+2^q$.

Find all $p,q$ primes such that $pq\mid 2^p+2^q$.   $Case 1(p=q=2)$ Then it satisfies condition of problem.  $Case 2(p=2,q\neq2)$. Then by Fermat's little theorem, $q\mid6\implies q=3$. It means $6\mid 12$ which satisfies condition of problem.  $Case 3(p,q\neq2)$. By Fermat's little theorem, $2^{p-1}\equiv -1(mod q)$ and $2^{q-1}\equiv -1(mod p)$. It means $2^{p+q-2}\equiv -1(mod pq)$. Now I don't know how to continue. Anyone can continue this?


Finding all integers $k \geq 2$ such that $k^2 \equiv 5k \pmod{15}$. What is going on here?

The question is as follows:      Find all integers $k \geq 2$ such that $k^2 \equiv 5k \pmod{15}$.   I have an issue related to this question (its not about the solution to the question):  I know that $\overline{k} \in \mathbb{Z}_{15}$ is invertible if and only if $k$ and $15$ are relatively prime. So, assume $\overline{k}$ is invertible. Then, $\overline{k}^2 = \overline{5}\overline{k}$ implies $\overline{k} = \overline{5}.$ But isn't $\overline{5}$ not invertible, since $5$ is not relatively prime with 15? What am I missing?


Given that the set {∨, $\wedge$ , ¬} is functionally complete, how would I prove whether the set $\{\to\}$ is functionally complete?   expressing $→$ in terms of $∨$: $¬A∨B$   expressing $→$ in terms of $∧$: $¬(A∧¬B)$  I understand the above two expressions, but cannot seem to prove that it is/is not functionally complete.


I have a small problem. I want to save web pages using Firefoxs "SAVE" button and then click the "Next" button to the next page and save it. In total I need to store 1000 pages.    Apparently I can't do it manually. It takes ages. The web page can't be downloaded by wget because they aren't simple html files. They use JavaScript files. Any good ideas?


Ctrl-Alt-Del Change password missing in Windows 10

I disabled the Remove Change Password but the change password option is still not showing with Ctrl-Alt-Del.  How do I get it back?   I need it badly because there is a domain where I connect only via VPN and have no access to any servers except the DCs.   (Why must Microsoft make things more difficult instead of easier?)    My policy setting for this item is:


I was experiencing problems with Ubuntu Desktop like missing and broken system packages, missing Unity package and other problems. So I decided that the best solution (without touching Windows files) is just to reinstall Ubuntu.  I looked everywhere and found the way but got confused as some say that I supposed to choose "Erase Ubuntu and reinstall", others say that I supposed to choose "Something else" and just select it manually while installation. I thought the first option would be better and just safer as I don’t want any of Windows files to be touched but it says that it has a bug that erases all other partitions...   Current Ubuntu version: 17.04 desktop 32bit will be replaced with 16.04.0 desktop 32bit (as 32bit 17.04 version is no longer available)   What’s the safer option to choose? And if the second one is, how to make sure it’s Ubuntu partition?


When reviewing, it is possible to edit the post that is presented. However, when what you are reviewing is actually a review audit and you click edit, the following message appears:     This post is deleted and cannot be edited.   See    Doesn't this kind of give the game away? It's literally telling you that you need to flag the post as it's an audit. When you do so you'll get the Congratulations message, giving you a free review point.  Is this a problem? Should this be Changed?


I have a Sapphire 5850 GPU.  When I install any drivers in ubuntu for it my games run very heavy - with some strange glitches in the video.  I went back to the default driver and the games in steam run perfectly - but I can'tt control my fan speed with any command or tool.  All ask for CCC and the ati driver. Is there any solution for my problem?


I have arranged a tourist visa of U.A.E. with 60 days validity and I can stay there up to 39 days as stated by the visa agent. I should leave at the 40th day.  Is it true if yes then how can i confirm it before travelling?


What does >> or double Angle brackets mean?

It seems like such a simple questions but I cant find any resource regarding it  In C/C++ , it means to store the read in a value from command prompt and store it inside a variable ,   How about in Shell Programming?


If $a$ and $b$ commute and $\text{gcd}\left(\text{ord}(a),\text{ord}(b)\right)=1$, then $\text{ord}(ab)=\text{ord}(a)\text{ord}(b)$.

Prove if $\operatorname{ord}(a)=m$, $\operatorname{ord}(b)=n$, and $\operatorname{gcd}(m,n)=1$, then $\operatorname{ord}(ab)=mn$.   I was reading this and was thinking how this proof would look like. I tried to do it and am not sure if this is correct. Here is what I did:  If $a$ and $b$ commute then $(ab)^{mn} = a^{mn} * b^{mn} = (a^m)^n * (b^n)^m = 1 * 1 = 1.$ So $ord(ab) | mn$.  Now, take $k = \operatorname{ord}(ab) = m^\prime * n^\prime$ where m' is relatively prime with $n$ and $n'$ is relatively prime with $m$. By the result above $m' | m$ and $n' | n$. Now we have $((ab)^k)^{m/m'} = 1$ since $(ab)^k=1$. But on the other hand, by the commutativity:  $$((ab)^k)^(m/m') =$$  $$((ab)^(m' * n'))^(m/m') =$$  $$ a^{n'm} * b^{n'm} = $$  $$(a^m)^{n'} * b^{n'm'}=$$  $$b^{n'm'} = 1$$  This implies that $n' * m'$ is divisible by $n$. But $m'$ is relatively prime with $n$, so we must have $n' = n.$ By symmetry, $m' = m$. So $ord(ab) = mn$.  Just to say this again, I want to prove if $a$ and $b$ commute and $m$ and $n$ are relatively prime then   $$ord(ab)=mn.$$   The comments are vague. I guess this must be the answer then and there probably is not another way to do this.


Which houses (are/is) this road connected to?

We are having a debate at my work on if "are" or "is" is the right word to use in the above sentence (actually, a similar sentence which is work-related).  I am aware that there are other ways of rewriting this sentence which avoids this confusion, but keeping the sentence structure in-tact, what is the right word to use here? and why?     Which houses ____ this road connected to?         are   is      First time poster here. Be gentle.


Virtual box error - Kernel Driver not installed

Hi I recently installed Ubuntu for the first time and I am trying to install and use virtual box. I am using Ubuntu 20.04. I downloaded the deb package from the virtual-box website and installed the software. Then I tried to import a virtual machine I was using on a mac. I got the following error.  Kernel driver not installed (rc=-1908)  The VirtualBox Linux kernel driver is either not loaded or not set up correctly. Please try setting it up again by executing  '/sbin/vboxconfig'  Then I ran the command /sbin/vboxconfig as root. I also turned off the UEFI from boot menu. (secure boot). Then I got the following error message. vboxdrv.sh: Stopping VirtualBox services. vboxdrv.sh: Starting VirtualBox services. vboxdrv.sh: You must sign these kernel modules before using VirtualBox:   vboxdrv vboxnetflt vboxnetadp See the documenatation for your Linux distribution.. vboxdrv.sh: Building VirtualBox kernel modules. debconf: DbDriver "config": /var/cache/debconf/config.dat is locked by another process: Resource temporarily unavailable vboxdrv.sh: Failed to enroll secure boot key.. vboxdrv.sh: failed: modprobe vboxdrv failed. Please use 'dmesg' to find out why.  There were problems setting up VirtualBox.  To re-start the set-up process, run   /sbin/vboxconfig as root.  If your system is using EFI Secure Boot you may need to sign the kernel modules (vboxdrv, vboxnetflt, vboxnetadp, vboxpci) before you can load them. Please see your Linux system's documentation for more information.  Any help on how to fix the error?


How to express the eigenvalue of $AB$ in tems of eigenvalues of $A$ and $B$

My friend has asked me to find out the relationship between  the eigenvalues of $AB$ with eigenvalues of $A$,$B$.Where $A,B$ are any two matrices.  My try:Let $A,B$ are two matrices with $v$ be a common eigenvector.Then $Av=x_1v$ and $Bv=x_2v$,$x_1,x_2$ are the eigenvalues of $A$ and $B$ respectively.Then $ABv=A(x_2v)=x_2(Av)=x_2x_1v$......So $x_1x_2$ is also the eigenvalue of $AB$.  If $A,B$ are $2*2$ matrices let $x_3,x_4,x$ are the other eigenvalues of $A,B,AB$ respectively.As we know $det(AB)=det(A)det(B)$,and the determinant of matrix is the product of it's eigenvalues; I get $x_1x_2x=x_1x_3x_2x_4$$=>x=x_3x_4$.So each eigenvalue of $AB$ is the product of suitable pair of eigenvalues from $A$ and $B$.If I generalize this result I can conclude that if the $n*n$ matrices $A,B$ has same $(n-1)$ linearly independent common eigenvalues then each of the eigenvalues of $AB$ is the product of suitable pair of eigenvalues of $A$ and $B$.  Can I extend this result in more general case?Is the condition "$A$ and $B$ has $n-1$ common linearly independent eigenvectors" is necessary?I will be happy if anyone give me any result almost familer to that result with another condition or any beautiful result concerning eigenvalues of $AB$.


Can we deploy PROFILES alone from one sandbox to another?

Can we deploy only profiles from one sandbox to another?  Thanks


From trigger beforeInsert how to stop the insert in the database table

Is there a possibilty in Salesforce from trigger beforeInsert how to stop the insert in the database table.


How can I clean up 'Other' storage on iPhone 3G?

My iPhone 3G is currently showing 3.1GB of 'Other' disk space in iTunes, and this amount seems to be growing by about 0.1GB every couple of days.  I can't find any good references for what this space could actually be getting used for.    I've heard of doing a restore to clear it up, which works, for about a day, but then the 'Other' space starts to quickly accumulate again.  I've also done all the Internet history clearing, turning off of indexing and removing of disabled mail accounts, still no success.  I'd love to know how to either clear this stuff up, or see a decent explanation for why my phone is using all this extra space.  Here's a snapshot of what my disk usage bar in iTunes looks like:   UPDATE: My phone is not jailbroken.  It is stock IOS 4.2.1.


I realize this question might have been asked already, but I'm relatively new to LaTeX and matlab so I need some help.  I'm trying to export a figure for inclusion in my tex document (to be compiled using pdflatex). The figure contains axes labels with LaTeX fonts (xlabel(...,'interpreter',latex)).  I've looked extensevely on the web but have not found a satisfactory solution.  My best solution so far is to produce a png file by using the savefig.m function, but the quality is not ideal  I'd be very grateful for any hints.


Can someone tell me which is grammatically sound in this context -- would or will? I've looked through some of the responses to similar questions, but the explanations weren't too clear for a non-native speaker like myself.  I'm not sure if this would make things more convenient for you, but I can meet you directly at the airport...  Or...  I'm not sure if this will make things more convenient for you, but I can meet you directly at the airport...  Many thanks.


Is a unit coupling coefficient for mutual inductance (so $M=\sqrt{L_1L_2}$) compatible with different self-inductances $L_1\neq L_2$?

We considered mutual inductance in my lectures and the definition $M=k\sqrt{L_1L_2}$ where the coupling constant $k$ can vary between 0 and 1. When covering transformers, my lecture notes "assume that all of the flux couples to both coils, such that the coupling coefficient is equal to unity". However I am not sure how this is the case, unless also the self inductance of each coil is the same (which certainly is not the case in the rest of my notes!).  In particular, the flux through each coil is  $$\phi_1 = L_1I_1 + MI_2 = L_1I_1 + k\sqrt{L_1L_2}I_2$$  and   $$\phi_2 = L_2I_2 + k\sqrt{L_1L_2}I_1$$  Equating these and rearranging, I find that   $$\sqrt{\frac{L_1}{L_2}}I_1 + \sqrt{\frac{L_2}{L_1}}I_2 = (I_1-I_2)k$$  so $$k=1 \iff L_1=L_2$$  Have I misunderstood what it means for 'all of the flux to couple to both coils'?


Reference request for Combinatorics problems

I'm looking for a book with variety of combinatorics exercises specially enumerative problems.  I have found some lecture notes but they were not coherent.  What do you advise?


when I open up the terminal and write the command   cd Desktop     also I have tried    cd /Desktop   a message appears that no file or directory was found what I suppose to do? I have logged in as  a root but still have the same problem any help?


Screaming Frog hreflang missing confirmation links for rel="alternative"

Screaming frog tells me that I have missing confirmation links in my hreflang, but I cannot seem to identify the problem. Here is a screenshot of the code on our Korean page:   Here is a screenshot of the code on our regular US page. Anyone have an idea of what I'm doing wrong? Thanks!


Removing and adding permission using numerical notation on the same line

I'm having some trouble trying to remove write permission from the owning group (g), and to add read permission to others (o) at the same time.   How would I remove some permission from the owning group and add some permission for others in the same line?


Can I record unrendered scene/animation?

I like how 3D View exposes me the auxiliary objects, like cameras, selected object coordinate system and TrackTo line. But all auxiliary objects are removed in the rendered view, that is stored to output device by animation. Can I render the animation in Solid view instead of Render, for instance?


How do I get google to show my page's structure in its results?

I know that for some pages Google lists the results as can be seen in the following screenshot:    As you can see, main navigation pages (About, Constructed, Contact etc.) are shown in an indented and table-like manner before the other results (urbalize.tumblr.com etc.) are shown.  My question is: How can I get Google to show the results of my (wordpress) page in the same way?  What I already tried: I assumed that submitting my sitemap (via sitemap.xml) to Google would help, but it didnt.   Is there anything else I have to do?


t test with drastically different sample sizes

I'm investigating if two of our processes are producing products with the same or different average measurements.   The first process has been used for a very long time and thus I have a sample size of 430 measurements for it.   The second process is very new and only has a sample size of 15 measurements for it.   I've done an F-test to compare the sample variances for what I have now, and I have no evidence to suggest the variances of the samples are different.   When I perform a t-test for the differences of averages, I get results that indicate a very significant difference between the two processes' measurements.   Is there any test out there that will achieve the goal as the t-test, but will also control for or take into account the very large sample size differences?


Is it not time to implement a mobile version of the site?  pros:   browsing experience greater availability more traffic   cons:   txtspeak answers fewer ad impressions


How to show Y number of custom posts after every X normal posts?

I have a loop within a loop. I figured out how to show all or X number of custom posts after Y number of normal posts. I also figured out how to show 1 custom post after every Y normal posts. How do I show X custom posts after EVERY Y number of normal posts.  In simple terms. How do I show 2 book (custom post type) posts after every 4 blog posts? How does one fetch more than 1 post at a time from the loop?  this is the logic of the x custom posts after y normal posts. how do i get x custom posts after EVERY y normal posts?  main query // normal query $k=0 // setting iterator while have posts, the post  ---post markup---   if($k == 4 or $k % 4 == 0) { // whether after x number or after every x number second query // using WP_Query while second query has posts, the posts  ---custom post type markup // I NEED TO SHOW MORE THAN ONE HERE IF IT IS AFTER EVERY X blogposts  endwhile; //second query ends  }  $k++; endwhile // main query


How to show that the ring is a Dedekind domain

How to show that $\mathbb{R}[x, y] / \langle x^2 + y^2 - 1 \rangle $ is a Dedekind domain?


Add notifications about accepted edit suggestions

Consider a new SO user with insufficient reputation to make an edit with no approval.  When such users suggest an edit, they can hardly guess that it is possible to keep track of their edit, discover if it is either approved or rejected, and that there may be a comment that describes a reason of the rejection that can help avoid the same situation in future.  The issue is that this tracking information is hidden deep inside a user profile. You need to follow User Page → All Actions → Suggestions (possibly). There is a little chance that an average newcomer even knows what “suggestions” is for, even if they are curious enough to dig into every tab of their own profile.  So I propose to add a notification in the Recent inbox messages area when a suggested edit is either accepted or declined. The notification entry must lead to a review page of a corresponding edit.


There was a comic that told the story of an underground society. A nuclear war was still going on. Radiation was seeping down into their caverns. A scientist was tasked to find a safer location deeper down. However, he found the mutated remnants of an earlier human society that experienced a previous nuclear war. Trying to recall the name of the comic or the story itself.  I am thinking mid 80's when I read this but could be an earlier time when it was written.


If an electron is a wave, what is waving?   So many answers on the internet say "the probability that a particle will be at a particular location"... so... the electron is a physical manifestation of probability? That doesn't sound right.   This page  seems to suggest that the spherical wave pair is what gives the electron the properties of a particle. I could be misinterpreting, but this answer makes more sense to me - if only I understood what was waving!


half a $ with the serial numbers question

I have a $100 US bill that is torn. Can I use the half with the serial numbers to get my money back from a bank?  I tried to use a vending machine and accidentally put in a 100 dollar bill. It tore it in half. I have a half with the serial numbers. Can I get the money back from the bank or the establishment?


I'm trying to do payment with Node.js, but find:  4.9 * 100 = 490.00000000000006   I can't stand this situation sometimes. How can I solve it?


Style first 3 posts differently with WP_Query

I've got the following code, which gets the first 3 posts. However, I am hoping to style each differently with if statements. But when I add if statements (to determine whether it is the first or second post), they are added, which on top of the first 3 posts: accidently creating 5 posts.  Is there a proper way to style the posts depending on whether they are first, second and third, but keep within the showposts => 3 attribute?      <?php      $lifestyle_cat = array(         'category_name' => 'lifestyle',         'showposts' => 3,         'post_type' => 'post',         'post_status' => 'publish',         'orderby' => 'date',         'order' => 'DESC'     );      $lifestyle_query = new WP_Query( $lifestyle_cat );     if ( $lifestyle_query->have_posts()) {         $i = 0;          while ( $lifestyle_query->have_posts()) {              $i++;             $lifestyle_query->the_post();                 if ($i==1) { // these are added and not within the 3 show posts                    ?>
 <?php  the_title();?>  i = 1
 <?php                 } elseif ($i==2) { // these are added and not within the 3 show posts                      ?>
 <?php  the_title();?>  i = 2
 <?php                 } ?>
<?php the_title(); ?>
  <?php } } else {         // no posts found     }      wp_reset_postdata(); ?>


Different representation of a Lebesgue integral

I was reading the proof of the Portmanteau Theorem, when this statement was made:  $\int{fdP} = \int_{0}^{supf}{P\{{f\geq t\}}dt}$  Here the P is a probability measure on a metric space, and $f\ge0$ is a real-valued  continuous bounded function on the same space. Now I am familiar with measure theory and intuitively this makes sense to me. But for some reason I cannot justify it on paper. Any help would be appreciated as to why this is so.


Can a water softener be installed after a thermal expansion tank?

Our thermal expansion tank is installed after the meter and feeds into the house and hot water heater. It seems like it should have been installed immediately prior to the water heater... Can I install a water softener after the thermal expansion tank or should I try to install it between the meter and thermal expansion tank?


How to get Linear dependent columns indices in big dataset?

I have a dataset which is a size of 50k x 280 i want to find linear dependent column indices so that i can eliminate them, rank of my matrix is 249 so what i understand that there are 31 columns are linearly dependent, i know a method to get directlty indices pf LI columns by sympy's rref() method but it is taking so long to get indices, as i know that we can also get LI columns by pearson coefficient but how to choose which columns are LI by looking at matrix of size 280 X 280 of P values.


Defaults to true.  If set to true replaces all instances of known swear words with replacements (comical or * based). If false renders the content as originally presented.  Benefits:    Reduces moderation requirements necessary to ensure that people behind corporate firewalls are not blocked by an errent swear word.   Stops idiots like me complaining about it.


Is the Minecraft Java edition still available for Windows 10?

I purchased the Java edition 6 years ago, but after some time I uninstalled it. A few weeks ago I wanted to play again. When I went to download it, I got a message that I have a free code for the Windows 10 edition, so I downloaded that edition, but I didn't like it (among other things, you couldn't press F3 to view your coordinates). Today I wanted to download the Java version again, but it seems I cannot; when I go to "Download", it says "You already own Minecraft" and I have an option to download it on Windows 10. Whatever I try, I always seem to end up with that message.  Is it still possible to play the Java edition on Windows 10?


What is the smallest amount of neutrinos needed to create a black hole?

Is there some smallest amount of neutrinos needed to create a black hole?  Note that this question is not at all the same as the question here .  The other question asks if one particle alone can be turned into a black hole and this question asks how many particles is needed to form a black hole. Now obviously from the other question we can deduce that one neutrino alone is not enough to create black hole but the question still remains: can we create black holes out of two particles, three, more, how many are required?


What is actually alternating current (AC)? And direct current (DC)? I've been reading several books about basic electric circuits analysis and they are contradictory.   Some books say that AC is the same as the sinusoidal stationary state. That is, a sine or cosine function (actually, they are the same only shifted horizontally). For instance, \$v(t) = A \sin(\omega t + \phi)\$. Acording to these books, DC is totally stationary (static), that is, the voltage and current are not time-dependant (\$v(t) = k\$, where \$k = \mathrm{const.}\$). Currents have the same form as voltages on each of these cases. According to other books, AC is any current that is changing (that is alternating) his sign over time (\$t\$). With maths notation: \$i(t_1) < 0\$ and \$i(t_2) > 0\$ for some \$t_1\$ and \$t_2\$ where \$t_1 \neq t_2\$. It could have any shape as long as it's alternating his sign.   I'm inclined to think that in practice wins the first option but maybe it's better the etymology of the second option.  Some other cuestions have relation to this:   Is AC a voltage that is the sum of a sinusoidal stationary state and a constant voltage? For instance, \$v(t) = A \sin(\omega t + \phi) + k\$. Is AC a shawtooth wave?


Show that the equation $e^z=az^n$ has $n$ solutions in the unit disc centred at the origin counting multiplicity.

Let $a \in \mathbb{C}$ be such that $|a| > e$. Show that the equation $e^z=az^n$ has $n$ solutions in the disk $D_1(0)$ i.e. the unit disk centred at the origin counting multiplicity.   I think I'm supposed to use use Rouches theorem to solve this. Thanks in advance.


60s short story where band gives concert ending with a nuke detonation

I’m looking for a short story from the sixties that had to do with a rock band giving a concert where the climax of the show was a detonation of a nuke. The US government sponsored the concert trying to convince the public to use nukes in Vietnam to end the war.    My Dad used to bring home science fiction anthologies home with him from his business trips and this is one of the stories I remember.


How do I return path to file if it exists in python

I have to check that file exists or not, and if it does, have to return path to it , the main problem is that os.path.isdir returns only True or False depending on existence, so it seems it does not fit. Any hints? Current schema in my mind  is:  def get_config_path():     if exists(path1):         return path1     if exists(path2):         return path2


Need help diagnosing a NullPointerException

I am new to generics and I am trying out to make a linked list.  Here is the Code for Node_ class.  public class Node_<T> {      private int index;     private T data;     private Node_<T> next;     public Node_() {     }      public Node_(T data, int index) {         this.data = data;         this.index = index;         next = null;     }      public void set(T data, int index) {         this.data = data;         this.index = index;         this.next= null;     }      public void display() {         System.out.println(this.data.toString());     }      public void setindex(int index) {         this.index = index;     }      public void setData(T data) {         this.data = data;     }      public Node_<T> getNext() {         return next;     }      public boolean hasNext() {         if (next != null) return true;         else return false;     }      public int getIndex() {         return this.index;     } }   and linked list class.  public class LinkList<T> {         private int total = 0;     private Node_<T> start;     private Node_<T> end;     private Node_<T> ptr;      public LinkList() {     }          public LinkList(T data) {         start = new Node_<T>(data, 0);         end = start;         ptr = start;         total++;     }      public void add(T data) {         if (start == null) {             start = new Node_<T>(data, 0);             end = start;             ptr = start;             total++;         } else {             end.set((T) data,(int) total);             total++;             end = end.getNext();         }     }       public void displayAt(int index) {         if (start != null) {             ptr = start;             do {                 if (ptr.getIndex() == index)                     ptr.display();             } while (ptr.hasNext());         }          else             System.out.println("No Element found");     }      public void displayAll() {         if (start != null) {             ptr = start;             do {                 ptr.display();             } while (ptr.hasNext());         }          else             System.out.println("No Element Present");     } }   The following code in Main class  public class Main {     public static void main(String[] args) {             LinkList<Integer> list = new LinkList<Integer>(25);         list.displayAll();         for (int i = 0; i < 11; i++) {             list.add((Integer) i);         }         list.displayAll();     }  }   I am getting the following error and i cant figure out the problem.  25 Exception in thread "main" java.lang.NullPointerException at LinkList.add(LinkList.java:26) at Main.main(Main.java:8)   Any suggestion where am I going wrong.


Virtualbox install 12.04 guest: "pae not present"

I get this message while trying to install Ubuntu 12.04 as a guest in VirutalBox 4.1.18, on an Ubuntu 10.04 host.         This kernel requires the following feature not present on the CPU: pae   Some host specs:     The host's kernel is: Linux 2.6.32-41-generic-pae GNU/Linux   lscpu (host): Architecture: i686, CPU op-mode(s): 32-bit, 64-bit   grep --color=always -i PAE /proc/cpuinfo   does show pae in its output.   The 12.04 iso used is: ubuntu-12.04.0-desktop-i386.iso      As a comparison/check, I downloaded and installed Linux Mint 13 Cinnamon to the same host on the exact same VM (I just changed the .iso image). It worked fine. Its iso is: linuxmint-13-cinnamon-dvd-32bit.iso   It seems (to me) that I have pae.. what is going on here?   Update: I had assumed that Linux Mint also required pae (being Ubuntu based), but I've just run;   grep --color=always -i PAE /proc/cpuinfo   in the Mint VM.   It showed no output.   So it seems the issue may lie with VirtualBox.   If that is the case, how can I get Virtualbox into pae mode?


Is this always true: $P(A|B) = 1-P(A^c|B)$?

Does this identity hold for all events?  $$ P(A|B) = 1-P(A'|B) $$  Logically speaking, if the probability of $A$ given $B$ occurred is $X$, shouldn't the probability that $A$ does not occur, $A'$, given $B$, be similarly $1-X$?  There is a related question .  This is the closest that I could get to proving (or disproving) it:   $P(A\cap B)=P(A)-P(A' \cap B)$ $P(A|B)P(B)=P(A)-P(A'|B)P(B)$ $\therefore P(A'|B)= \frac {P(A)} {P(B)}-P(A|B)$   Are there are certain formulae which can be used to prove this? Or does the identity only hold under certain situations, and if so, what kind of situations?  Thanks.


Folks, I want to know if there exists a command that just highlight some portions of the input text, rather than filtering it like grep does.  To give an example, suppose the following input text:  foo bar gaz das xar   grep "bar\|gaz" input would print the first two lines, highlighting bar and gaz, but would not display xar.  I'm aware that I could simply set a big constant to the -C argument, so it would "always" show the context, like: grep -C1000 "bar\|gaz" input, but I'm not sure if that is efficient, or if there is a better tool for that.


Should I be more worried about creating a consistent UI among platforms or creating native experiences?

I am starting to develop for all three major mobile platforms (Android, iOS, and Windows UWP), and have run into a UX issue a few times. Each platform has it's own design guide. Android has Material, Windows has Metro (I'm not sure what iOS's is called). Each design looks really good on its platform and only its platform. For example, Material looks beautiful on Android, but it would seem odd on iOS.   Now, I would like to follow these guidelines, and design per platform, but I feel that users would like it better if the app had a consistent design across all platforms. Furthermore, I also develop web apps, and since the web has no real "design guide", I would have to make yet another design. I could choose one design and make it universal across all platforms, but I feel like I would be performing some sort of "bad practice" to not use Metro and Material, and so on (plus, it may end up being harder to design and might look out of place).  In this scenario, what should I do? Use native styles for the different platforms, or create a single style, to be used across all platforms.


Why is the formula for calculating euler totient true?

I know that the way to calculate Euler Totients of a number X is to take the prime factorization of X and then use the rule $φ(p^n) = p^n - p^{n-1}$ on each of those prime factorizations and multiply all of the results together. My question is why do these hold true. First, what allows you to say that $φ(A \cdot B) = φ(A) \cdot φ(B)$ and also why $φ(p^n) = p^n - p^{n-1}$.


Merge two arrays as key value pairs in PHP

I've got two arrays of the same size.  I'd like to merge the two so the values of one are the key indexes of the new array, and the values of the new array are the values of the other.  Right now I'm just looping through the arrays and creating the new array manually, but I have a feeling there is a much more elegant way to go about this.  I don't see any array functions for this purpose, but maybe I missed something?  Is there a simple way to this along these lines?  $mapped_array = mapkeys($array_with_keys, $array_with_values);


Find all real-valued functions $h$, defined and of class $C^2$ on the positive real line, such that the function $u(x,y)=h(x^2 + y^2)$ is harmonic.   I was thinking that it will be harmonic only if $h$ will be constant.  My attempt:    Since $u$ is harmonic, $$ u_{xx}+u_{yy}=0 $$  $ u_{xx}=4x^2h_{xx}+2h_x $ and $u_{yy}=4y^2h_{yy}+2h_y$. So,  $$ 4\Big(x^2h_{xx}+y^2 h_{yy}\Big)+2\Big( h_x+h_y \Big) =0$$ After that I stuck. Any hint will be appreciated.


find not recursive when given a pattern on the command line

Imagine a source tree. There are xml files everywhere.  But since there is a XYZ.xml at the root of this tree it won't find my xml files.  find -iname *.xml   returns  ./XYZ.xml   instead of  ./XYZ.xml ./a/b/c/bob.xml ./b/d/top.xml


Calculation of Integral values of $x$ for which the expression $x^2+19x+92$ is a perfect square.  $\bf{My\; Solution::}$ Let $x^2+19x+92 = k^2\;,$ where $x,k\in \mathbb{Z}$  $$x^2+19x+(92-k^2)=0$$  Now $$\displaystyle x = \frac{-19\pm \sqrt{19^2-4(92-k^2)}}{2} = \frac{-19\pm \sqrt{4k^2-7}}{2}$$  Now for perfect square $\displaystyle 4k^2-7 = 0\Rightarrow k=\pm \frac{\sqrt{7}}{2}$  But it is wrong,  Please explain me how can i solve it and where i am wrong,  thanks


A nice way to see that $(\ell^\infty,d_\infty)$ is not separable

Let $(X,d)$ a metric space such that $\exists A\subseteq X$  uncountable and $\exists \epsilon\gt0$ such that $\forall x,y \in A,x\neq y\Rightarrow d(x,y)\gt\epsilon$. Prove that $X$ is not a separable space and and use this result to show that $(\ell^\infty,d_\infty)$ is not separable.  There is a result that says that in a separable metric space, every uncountable subset contains a point of accumulation. There is a result that says that in a separable metric space, every uncountable subset contains a point of accumulation. I started considering the result, which did not lead to anything. Then, by contradiction, I wanted to prove that $X$ is separable. In order to use that, I could see if $X$ has a countable base or a cover of open sets of $X$ has a countable subcover.


How to create bootable USB when you are currently using 'Try Ubuntu'?

The issue is the following: I need to create a working WindowsBootUsbStick from Try Ubuntu.  I am currently using from an Ubuntu-Boot-USBStick the 'Try Ubuntu'. Which is pretty neat - I set it up to download the WIN10 iso file on one of a Fat32 partition.  After that, I need to burn a bootable USB stick from here to set up Windows. What are the commands through Terminal to create a USB stick and burn an .iso to it?   Background story: I originally tried several methods - and to make you laugh - I am sitting among different USB sticks with Win7/Win10.    First I tried to create Win10USB from MacOS with UneBootin (1) This was working until it stops at the setting up Windows 10 /Of course, I tried to solve it with different methods with BIOS/  Then I downloaded another torrent-version of Win10 and created boot USB and same procedure it gave another error(2) Then I downloaded the official one from Microsoft.com (3) and go through the same procedure.  Then I tried to choose another boot program, in that case, I created the USB-Boot from MacOS Terminal(4) - it is not even working but the creation I think pretty similar like here.   So now I need to navigate(I) from the terminal the ISO file then I need a command to create a bootable stick from there(II).   By the way, the UbuntuBoot is working properly so from here I can easily get an up and running Ubuntu but before I need Windows.   These are the partitions what I created with the 'Try Ubuntu' mode.  Device         Start       End   Sectors   Size Type /dev/sda1       2048 104974335 104972288  50.1G Microsoft basic data  /dev/sda2  104974336 167888895  62914560    30G Linux filesystem  /dev/sda3  167888896 230864895  62976000    30G Linux filesystem  /dev/sda4  230864896 976773119 745908224 355.7G Microsoft basic data   I also created a folder at the FAT32 partition at /dev/sda4 with the name of the Folder: 'Downloads' So first question:   How can I reach the .iso file from Terminal?      Then how can I create the bootable USB stick with the Win10.iso file?


Why do many graduate programs in mathematics (United States) still have foreign language requirements today (in 2010s)?

As far as I know, nowadays most of the mathematical literature is written and published in English and mathematicians communicate with each other in English. Although there are certain number of books written in other languages (like EGA), but at the same time their counterparts also appear in English (like Stacks Project). However, many graduate programs still require their students to pass a language translation test in French, German or Russian (which a paper dictionary, not a dictionary app in cellphones, which seems even more ridiculous to me...). I wonder what makes it still necessary to have foreign language requirement as of 2010s.  I believe my question has different focus than this one     Where the questioner specifically asked for advice for the most useful language among French, German and Russian:  I personally have no preference on which to learn, but I was wondering if there were other reasons that would make one language more advantageous over the others in terms of a general mathematical career.  while I am asking why we ever need a second language for mathematical study in 2010s:


save programdata at computer shutdown in java

I work on a program which saves data in a database when shutting down the program. Now it would be nice if that happend also at a system shutdown. I am curious if this is possible somehow in java 8 (Oracle JDK ). It should work for Ubuntu (16.04 and newer) and Windows 10.  Probably I have to tell the OS somehow to wait till the app finished.


Really advanced techniques of integration (definite or indefinite)

Okay, so everyone knows the usual methods of solving integrals, namely u-substitution, integration by parts, partial fractions, trig substitutions, and reduction formulas. But what else is there? Every time I search for "Advanced Techniques of Symbolic Integration" or "Super Advanced Integration Techniques", I get the same results which end up only talking about the methods mentioned above. Are there any super obscure and interesting techniques for solving integrals?  As an example of something that might be obscure, the formula for "general integration by parts " for $n$ functions $f_j, \ j = 1,\cdots,n$ is given by $$ \int{f_1'(x)\prod_{j=2}^n{f_j(x)}dx} = \prod_{i=1}^n{f_i(x)} - \sum_{i=2}^n{\int{f_i'(x)\prod_{\substack{j=1 \\ j \neq i}}^n{f_j(x)}dx}} $$ which is not necessarily useful nor difficult to derive, but is interesting nonetheless.  So out of curiosity, are there any crazy unknown symbolic integration techniques?


How can Lazy provide thread safe lazy loading when it's .value property does not lock?

Ok, so I've been looking at the  because I want to extend it. I know that in theory, it is supposed to be thread safe, but I don't know how it can be. Looking it's it .value getter, it does not lock on anything before reading the value.  public T Value {     get     {         Boxed boxed = null;         if (m_boxed != null )         {             // Do a quick check up front for the fast path.             boxed = m_boxed as Boxed;             if (boxed != null)             {                 return boxed.m_value;             }               LazyInternalExceptionHolder exc = m_boxed as LazyInternalExceptionHolder;             Contract.Assert(m_boxed != null);             exc.m_edi.Throw();         }          // Fall through to the slow path. #if !FEATURE_CORECLR         // We call NOCTD to abort attempts by the debugger to funceval this property (e.g. on mouseover)         //   (the debugger proxy is the correct way to look at state/value of this object)         Debugger.NotifyOfCrossThreadDependency();  #endif         return LazyInitValue();      } }   It's my understanding that to be thread safe, something must lock when both writing as well as reading, because if a read get's interrupted by a write it can return incorrect data or even have an error. Is this understanding correct, or is something complicated happening with Lazy<T>?


I switched from windows to Ubuntu yesterday and I'm just starting. I had two partitions on windows as it's normal there and I left as it was. I want to install software on Local Disk :D, not C, but I have no idea about the solution. Can anyone help me?


Python: Split a string, respect and preserve quotes

Using python, I want to split the following string:  a=foo, b=bar, c="foo, bar", d=false, e="false"   This should result in the following list:  ['a=foo', 'b=bar', 'c="foo, bar"', 'd=false', 'e="false'"']   When using shlex in posix-mode and splitting with ", ", the argument for cgets treated correctly. However, it removes the quotes. I need them because false is not the same as "false", for instance.  My code so far:  import shlex  mystring = 'a=foo, b=bar, c="foo, bar", d=false, e="false"'  splitter = shlex.shlex(mystring, posix=True) splitter.whitespace += ',' splitter.whitespace_split = True print list(splitter) # ['a=foo', 'b=bar', 'c=foo, bar', 'd=false', 'e=false']


I was having a go at making a simple machine learning program so I could understand more about AI, but ran into a problem. My program has a 2D list (101 lists of 3 Boolean values (303 total)). It does several loops, and has to set 1, or 2 values from one of the sub lists to True in each loop. When running my program, all values changed to true far too quickly. At first, I thought this might be due to bad luck with random(), but then I saw that all the values changed after only 90 to 100 loops, which should be impossible.  I decided to experiment in the shell.  >>> Choises=[[False]*3]*101 >>> Choises[1][1]=True >>> Choises [[False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False], [False, True, False]]   Why on earth did it change the 2nd value of each list, rather than just the 2nd value of just the 2nd one?


Can't set Transmission to download files

Just installed Ubuntu 12. on my new computer. When trying to download files I want to use Transmission but after I choose a file to download Transmission is not in the list of programs to run with (infact it's empty) and when I click "Choose a program" (or whatever it says in english") and find the folder Transmission there's no file or program to choose from (I also choose "show hidden files", the folders within the Transmission folder are empty exept for settings.json. When I go to the list of settings in Firefox, Transmission are not among these and I don't know how to add it. Please, help. Want to getting started downloadning again.


How to perform chroot with Linux namespaces?

After reading about Linux namespaces I was under the impression that they are, amongst a lot of other features, an alternative to chroot. For example, in :     Other uses [of namespaces] include [...] chroot()-style isolation of a process to a portion of the single directory hierarchy.   However, when I clone the mount namespace, for example with the following command, I still see the whole original root tree.  unshare --mount -- /bin/bash   I understand that I am now able to perform additional mounts in the new namespace that are not shared with the original namespace and thus this provides isolation, but it is still the same root, e.g. /etc is still the same for both namespaces. Do I still need chroot to change the root or is there an alternative?  I was expecting that  would provide an answer, but the answer only uses chroot, again.  EDIT #1  There was a now deleted comment that mentioned pivot_root. Since this is actually part of , it is in fact part of the namespaces implementation. This suggests that changing the root directory only with unshare and mount is not possible, but namespaces provides an own - more clever - version of chroot. Still I do not get the main idea of this approach that makes it fundamentally different from chroot, even after reading the source code (in the sense of e.g. security or better isolation).  EDIT #2  This is not a duplicate of . After executing all the commands from the answer I have separate /tmp/tmp.vyM9IwnKuY (or similar), but the root directory is still the same!


How to understand and control PC suspension

I am using Windows 7 and it goes "off" periodically, I presume either suspended or screen locked (how can I tell the difference?)  This is a problem because sometimes I run applications that should not be suspended. For example, today I had the laptop in a car and it was reading the OBDII sensor via a USB connector collecting live data. In the middle of the trip the screen went dark. When I clicked it, the rainbow with the clock appeared, I clicked that and it invited me to log in. Was the computer suspended, thus interrupting the collection of data?  How can I understand and control the mode of the computer to ensure that vital processes that should not be suspended continue running?  These are my current power settings:    This would seem to suggest the computer would never sleep or hibernate, so am I safe in assuming that the data collection was not interrupted? I saw no data file in the directory where it supposed to be, so I am afraid it may have been interrupted anyway somehow.


I'm trying to create a class (Team) but I'm getting a nullpointer error This is where it's called  Team[] Teams = new Team[6];    private void AddTeamButtonMouseClicked(java.awt.event.MouseEvent evt) {                                                    String InputTeamName = TeamNameInput.getText();          switch(TeamCounter)         {             case 0:                 Teams[TeamCounter].Name = InputTeamName;                 Team_1.setText(Teams[TeamCounter].Name);                 TeamCounter++;                 break; }   Team Class  public class Team  {     String Name;     Player[] Players = new Player[5]; }


How to create an SHA-512 hashed password for shadow?

The previous SF questions I've seen have lead to answers that produce MD5 hashed password.  Does anyone have a suggestion on to produce an SHA-512 hashed password? I'd prefer a one liner instead of a script but, if a script is the only solution, that's fine as well.  Update  Replacing previous py2 versions with this one:  python3 -c "import crypt;print(crypt.crypt(input('clear-text pw: '), crypt.mksalt(crypt.METHOD_SHA512)))"


Find the minimum value of $\sin^2\theta+\cos^2\theta+\csc^2\theta+\sec^2\theta+\tan^2\theta+\cot^2 \theta$

What is the minimum value of this expression?   $$\sin^2\theta+\cos^2\theta+\csc^2\theta+\sec^2\theta+\tan^2\theta+\cot^2 \theta$$   I tried grouping $\sin^2x+\csc^2x$, $\cos^2x+\sec^2x$ and $\cot^2x+\tan^2x$.  I got the answer as $6$ but the book says $7$. How?


I2C pull-up resistors calculation & where to place them

I'm connecting a  (master) to a  (slave) using I2C. The wire between the devices is ~30cm. I'm using 400kHz without slew rate control. Later on, I'll add another 18F4620 on ~5cm from the master (~35cm from the other slave).  How do I calculate the pull-up resistance needed on both the SCL as the SDA line?   Does it matter where I place the pull-up (near the master, near the slave, both, in the middle, ...)?


Difference between $\Delta$, $d$ and $\delta$

I have read the thread regarding , but it does not answer my question.  I am confused about the notation for change in Physics. In Mathematics, $\delta$ and $\Delta$ essentially refer to the same thing, i.e., change. This means that $\Delta x = x_1 - x_2 = \delta x$. The difference between $\delta$ and $d$ is also clear and distinct in differential calculus. We know that $\frac{dy}{dx}$ is always an operator and not a fraction, whereas $\frac{\delta y}{\delta x}$ is an infinitesimal change.   In Physics, however, the distinction is not as clear. Can anyone offer a clearer picture?


How and where can I install threeparttable.sty?

I want to install threeparttable.sty to add footnotes into tables, but I don't know where and how. I tried by Miktex, but didn't work for an error on connection.  The package is online   Thanks for all


Flagging a comment doesn't count as a review

While reviewing First Posts or Late Answers if you upvote a comment, it counts as "reviewed".  If you flag a comment (for any reason) it doesn't count.  Is this intentional? Any particular reason behind it?


Proving $|G|=pq$ and $p>q$ , $q$ does not divide $p-1$ $\implies$ $G$ is cyclic , without using Cauchy's and Sylow's theorems

Without using Cauchy's or Sylow's theorems , can we give a proof of the result that "If $ p,q$ are primes such that $p>q$ and $q$ does not divide $p-1$ , then any group of order $pq$ is cyclic " ?


What is the difference between RGB and CMYK colours?

Why does the printer ask for all colours to be in CMYK, cant you sometimes send them as RGB like when you might print them from an office printer?


Who are the clients of my shared iTunes library?

Is it possible to see who is currently connected and listening to a shared iTunes library? Is it possible to see which songs they listen to and how many/often?  It's not really important; I'm just curious about it. Would be nice to know which colleagues love my music…


Is there any difference between the two prononciations, /ˈter-ə-bəl/ and /ˈte-rə-bəl/, showed in the picture?

For the word terrible, there are two different ways to pronounce it on Merriam-Webster:  ter·ri·ble | \ ˈter-ə-bəl, ˈte-rə- \  And this question has been confusing me for a very long time. When the R-controlled vowel followed by a vowel in a word, should we pronounce the R-controlled vowel as in the same syllable or the r sound should be pronounced with the vowel after it?


Early sf short story about a talking storytelling device

In this story there is a toy device that can tell stories. The author manages to portray the impression that the device has some kind of increasing capability to empathise with the listener.  In the end, the machine breaks and just repeats a phrase over and over, which I cannot remember.  This story left quite an impression upon me as a child, would be great to find out who wrote it so I can read it again as an adult.


Programming Puzzles & Code Golf does not fit in Stack Exchange

Isn't StackExchange a network to build a knowledge base for Google? Or to help people?  Yes, it is. So why is there the Programming Puzzles & Code Golf website? What problems are solved there? What questions are asked there?  None.  Therefore, I think Programming Puzzles & Code Golf doesn't fit into the philosophy of StackExchange. It should or   get it's own domain be removed (though I wouldn't do that)   I would love to hear your thoughts on this!


Error installing Mac OS X 10.10 (Yosemite) on a 512GB SSD in my 2010 MacBook

The Mac OS X 10.10 (Yosemite) installer fails to extract any files onto my drive:  OS X could not be installed on your computer An error occurred while extracting files from the package "Essentials.pkg". Quit the installer to restart your computer and try again.  However, I have reinstalled Mac OS X 10.9.5 (Mavericks) just fine, which leads me to believe there’s something wonky going on with the installer. Judging by the comments on , it seems like this error might be occurring with people who have installed SSDs in their old MacBooks. I have a mid-2010 MacBook with a 512GB SSD in the main hard drive slot and a secondary 250GB HDD in the DVD drive bay. I also have installed 16GB of RAM in this laptop. So far all of the new hardware has worked fine for the past 6 months so I doubt my issues are due to faulty hardware. I am trying to perform the install on a freshly formatted partition. Here is the . Here’s  from when I was trying to upgrade the OS instead of using a freshly formatted partition.


I want to make the code shorter. I defined the following pair of macros:  \def\b*{\begin{align*}} \def\e*{\end{align*}}   My point is that I saw this in a document, with  \def\b*{\begin{eqnarray*}} \def\e*{\end{eqnarray*}}   instead. The first pair of macros do not compile (on sharelatex.com), and the second one does. Why?


How to uprade from 12.04 to 14.04 LTS without internet connection ?

I just installed Ubuntu 12.04 and want to update to Ubuntu 14.04 LTS but do not have an internet connection or another Ubuntu PC. I don't have an internet connection as the network modem drivers only works on windows and mac OS X. Can i just update it by putting it on usb and then onto the Ubuntu PC?


Why would one need to mix the dry ingredients (flour, salt, soda) separately and before mixing into the liquid (butter, sugar) than just mixing everything into one bowl at the same time when making cakes? What would be the result if done ?


Can't understand a proof: Let $a,b,c$ be integers. If $a$ and $b$ divide $c$, then $lcm(a,b)$ also divides $c$  Proof I've been shown:  Since $c$ is a common multiple of $a,b$, it means that $lcm(a,b) \leq c$.  So: $c=q\cdot lcm(a,b)+r$, $q \in \mathbb Z$ and $0\leq r \leq lcm(a,b)$  Since $c$ and $lcm(a,b)$ are common multiples of $a,b$, then so is $r$. But $m$ is the least common divisor, then it means $r=0$.   [Proof taken from: http://www.math.utah.edu/~wood/4400/hw1sol.pdf]  I cannot understand the last step... Why does it imply that $r=0$?   Thank you!


float comparsion (operator !=) returns false, but numbers are equal although the numbers appear to be the same

I wrote a small test to evaluate my programm, but somehow a weired thing happens:     Values of the vector(as printed using 'cout' in the first loop):   0.06   0.06   0.06   0.06   0.06   0.6       Message triggered by the call of function fail         Adjustment at i=4 was 0.06, but should have been 0.06   Somehow this fairly easy comparison of two floats returns false in this loop, but numbers are equal printed and should be equal. Furthermore from i=0 to i=3 comparison of the values evaluate as they should (returning equal)  Somebody know what the problem is?  vector<float> adjustment = *adj.getCalculatedAdjustment(); for (vector<float>::iterator it = adjustment.begin();it!=adjustment.end();it++){     cout << *it << "\n"; } for (unsigned int i=0;i<adjustment.size()-1;i++){     if (adjustment[i]!=(float)0.06){         stringstream ss;         ss << "Adjustment at i=" << i << " was " << adjustment[i] << ", but should have been 0.06";         fail(ss.str());     }  }


Can I assign a keyboard shortcut to bring up the Mac OS X Login Window?

I’d like to assign an “Every Application” keyboard shortcut to bring up the login window, for when I step away from my computer. Is there a way to do this? (Lion-only methods are fine.)


I quite often get stuck trying to solve particular problems, or getting syntaxes right.   Apart from the details provided in the links on , does anyone know of any 3rd party resources/manuals explaining it in a bit more user friendly way?