Interpreting the residuals vs. fitted values plot
Interpreting the residuals vs. fitted values plot for verifying the assumptions of a linear model
Could Hermione really free the Hogwarts house-elves with her knitted hats? How to format date and time in Android? How can I play encrypted DVD movies? My machine can't play encrypted DVDs on a fresh install.  How do I add this capability?  Another useful bit of information would be what programs are best for playing DVDs, once I'm able to do so.  See the .  Will I be able to play DVD movies from ? I'm currently doing a couple of exercises on logarithmic expressions, and I was a bit confused when presented with the following: $5^{\log_5 17}$.  The answer is $17$, which is the argument of the logarithm in the exponent, but I don't understand the reason why.  A previous question in the exercise was $12^{\log_{12} 144}$, which is pretty straight forward since $\log_{12} 144=2$ and $12^2=144$ but since $\log_5 17$ is an irrational number, I couldn't calculate it the same way.  So my question is, why is $x^{\log_x n}=n$?  [Update]  I've now managed to reason this out and realized how simple it is.  Basically, if $y=\log_x n$, then $y$ is the number that  $x$ must be raised to to become $n$; therefore, if I raise $x$ to that power $y$, I will naturally get $n$.  I guess my problem was that I tried to work out the question mechanically instead of intelligently and that's why I failed, because once I realized that I can't calculate $\log_5 17$, I was stumped.  Now that I reasoned it out, as explained in the previous paragraph, I understand it. Confirmation that someone is listening to another person's speech When someone is telling you a very long and detailed story he usually wants to hear some "confirmations" (or response) that you are listening to his story. In Russian we often use something like "tak" (which has a meaning of "ok" and "well, proceed further"), "a-ha" or "uh-huh".  What word serves the same purpose in English and American English? Where can I find other RPG players? I'd really like to learn how to play pen-and-paper RPGs.  I know that it takes a few players to actually sit down and play, but I'm not at all sure where to find more gamers.  How do I find existing groups to join? Or, are there any resources online that may help me find existing RPG groups or players? It would be nice to be able to put emphasis on specific bits of a fragment or of a quote (bold can help for a quote but I find that it makes things less readable sometimes). What do you think? Update: On , you can highlight particular lines by prefixing each line with @@. See also: Is there any way to get the ID of the element that fires an event?  I'm thinking something like:    $(document).ready(function() {   $("a").click(function() {     var test = caller.id;     alert(test.val());   }); }); &lt;script type="text/javascript" src="starterkit/jquery.js"&gt;&lt;/script&gt;  &lt;form class="item" id="aaa"&gt;   &lt;input class="title"&gt;&lt;/input&gt; &lt;/form&gt; &lt;form class="item" id="bbb"&gt;   &lt;input class="title"&gt;&lt;/input&gt; &lt;/form&gt;     Except of course that the var test should contain the id "aaa", if the event is fired from the first form, and "bbb", if the event is fired from the second form. Realtek RTL8723be doesn't have good reception Only when I'm closer to the router, it shows any signal, but when I'm just little far from it, it is not showing wifi routers signals. Displaying row/column of point in raster using QGIS? Is it possible in QGIS to display column and row index of pixel in raster?   I mean something similar to value tool. I want to create a   How can I create a formfield with N fields, each 5 mm wide with separations like in the picture?    At the moment I use a workaround with a for loop, but this renders the code hard to maintain. Finally I need a function \formline{N}{cellwidth}{label}{value} to create the complete formfield and fill it with an optional value:   The following code is available on .   \documentclass[a4paper,11pt]{article} \usepackage[utf8]{inputenc} \usepackage{tikz} \usetikzlibrary{shapes}  \thispagestyle{empty} % no pagenumber. The form should be a stand alone macro... later.  \definecolor{SEPAOrange}{RGB}{254,213,161} \definecolor{SEPADOrange}{RGB}{253,185,19} \definecolor{SEPABlindcolor}{RGB}{255,0,0} \begin{document} \begin{tikzpicture}[x=1 mm, y=-1mm] \pgfmathsetmacro{\yh}{4.2333} % y heigth step defined as 1/6 inch =&gt; 1/6 * 25.4 mm = 4.2333 mm \pgfmathsetmacro{\xs}{9} % x start (own definition) \pgfmathsetmacro{\xe}{141.5} % x end (own definition) \pgfmathsetmacro{\widefield}{4.9859} % def: 134.62 mm / 27 \pgfmathsetmacro{\narrowfiels}{3.9594} % def: 134.62 mm/ 34  \filldraw[draw=black,color=SEPAOrange] (7.62, 4.5*\yh) rectangle (149.86-7.62,105.83-1); %orange background  \filldraw[draw=black,color=white] (\xs, 5*\yh) rectangle (\xe, 6.5*\yh -1.5); %Recepient 27 Char \foreach \x in {1,...,26} {  \draw[color=SEPAOrange, line width=0.3mm] (7.62 + \x*\widefield, 5*\yh ) -- (7.62 + \x*\widefield, 6.5*\yh);  \draw[color=SEPAOrange, line width=0.7mm] (7.62 + \x*\widefield, 5.8*\yh ) -- (7.62 + \x*\widefield, 6.5*\yh); }  \filldraw[draw=black,color=white] (\xs, 7*\yh) rectangle (\xe, 8.5*\yh -1.5); %IBAN 34 Char \foreach \x in {1,...,33}  \draw[color=SEPAOrange, line width=0.3mm] (7.62 + \x*4, 7*\yh ) -- (7.62 + \x*4, 8.5*\yh);  \filldraw[draw=black,color=white] (\xs, 9*\yh) rectangle (\xe, 10.5*\yh -1.5); %BIC \filldraw[draw=black,color=white] (\xe-12*5, 11*\yh) rectangle (\xe, 12.5*\yh -1.5); %Value 12 Char  \filldraw[draw=black,color=white] (\xs, 13*\yh) rectangle (\xe, 14.5*\yh -1.5); %Subject1 \filldraw[draw=black,color=white] (\xs, 15*\yh) rectangle (\xe, 16.5*\yh -1.5); %Subject2 \filldraw[draw=black,color=white] (\xs, 17*\yh) rectangle (\xe, 18.5*\yh -1.5); %Subject3  \filldraw[draw=black,color=white] (\xs, 19*\yh) rectangle (\xs+22*5, 20.5*\yh -1.5); % IBAN 22 Char  \filldraw[draw=black,color=white] (149.86-17.59, 19* \yh) rectangle (\xe, 20.5*\yh -1.5); % counter \filldraw[draw=black,color=white] (\xs, 21* \yh) rectangle (42.52, 24.5*\yh); % date \filldraw[draw=black,color=white] (42.52+5, 21*\yh) rectangle (149.86-17.59, 24.5*\yh); % signature  \draw[color=SEPADOrange] (0, 4.5 *\yh) --(149.86, 4.5*\yh); upper dark orange line \draw[color=SEPADOrange] (0, 20.5 *\yh) --(149.86, 20.5*\yh); lower dark orange line \draw[draw=black,color=black, line width=0.3mm] (0,0) rectangle (149.86,105.83); % black border %\draw[align=left] at (\yh,\yh) {SEPA-Überweisung};  \end{tikzpicture} \end{document} Main page of StackOverflow на Русском Meta gives error The data for the tag search is still loading; please retry in a moment. Tighten rope without turnbuckles? I have two 4-ft x 4" x 4" wood posts, and each post has a screw eye. There's 12 feet of distance between each post.  How can I tighten a piece of 1/2" diameter rope that goes through each screw eye and it's stretched tightly without having to buy turnbuckles?  There has to be a knot just for this. Ubuntu 14.04 LTS fails to start with a kernel panic Basis of the null space Find the basis of the null space for the matrix  $$D = \begin{bmatrix}0 &amp; 0 &amp; 0 &amp; 0\\0 &amp; 1 &amp; 1 &amp; 0\\1 &amp; 1 &amp; 0 &amp; 0\\1 &amp;1 &amp; 0 &amp; 0\end{bmatrix}.$$  I computed the solution by letting eigenvectors $(x,y,z,w)$ such that $y+z=0,x+y=0$, and I got a basis vector $\{(1,-1,1,0), (0,0,0,1)\}$ . But from one textbook  I have found the solution as $\{(1,0,0,0),(0,0,1,1)\}$. May I made a mistake? Thanks! I'm getting errors in a matrix equation. When I compile it looks fine, but I'd like to fix them so I don't have to press return for every error at compile time. The code for the equation is:  \begin{equation*}  \begin{bmatrix} U(1,t)  &amp; \cdots &amp; U(n,t) \\  \vdots &amp; \ddots &amp; \vdots \\ O_{n1} &amp; \cdots &amp; O_{nn}  \end{bmatrix} \times \begin{bmatrix} W(1,1)  &amp; \cdots &amp; W(1,n) \\  \vdots &amp; \ddots &amp; \vdots \\  W(n,1) &amp; \cdots &amp; W(n,n)  \end{bmatrix} = \begin{bmatrix}  D(1,t)  &amp; \cdots &amp; D(n,t) \\ \vdots &amp; \ddots &amp; \vdots \\ I_{n1} &amp; \cdots &amp; I_{nn} \end{bmatrix}  \end{equation*}   The errors I'm getting are related to missing $'s inserted. Running JAR file on Windows I have a JAR file named helloworld.jar. In order to run it, I'm executing the following command in a command-line window:  java -jar helloworld.jar   This works fine, but how do I execute it with double-click instead? Do I need to install any software? Custom one-key keyboard shortcuts in Outlook 2010 or 2013? I have a script myscript.sh  #!/bin/sh  echo $1 $2   which is used something like ...  ./myscript.sh foo bar   which gives me an output of ...  foo bar     but how can i make this script include custom command options? for example ...  ./myscript.sh -a foo and corespond to $1   and  ./myscript.sh -b bar and corespond to $2 For a command, if using - as an argument in place of a file name will mean STDIN or STDOUT.   But in this example, it creates a file with the name -:  echo hello &gt; -   How can I make - in this example mean STDOUT? Conversely, how can I make - mean a file named - in examples such as:  cat -