I was met with this unpleasant surprise when trying to compile this file:  \documentclass{standalone}  \usepackage{pgfplots}  \pgfplotsset{compat=1.13}  \begin{document}  \begin{tikzpicture}      \begin{axis}[view={0}{90}]     \addplot3[domain=-10:10,         contour gnuplot={labels=false,levels={1}}     ]{(x+1)^2/4-(y-2)^2/9};     \end{axis}  \end{tikzpicture}  \end{document}   The file produces this error:  ! Package pgfplots Error: sorry, plot file{test_contourtmp0.table} could not be opened.   I did some digging and found out that my file is trying to borrow gnuplot functionality. Well, I installed gnuplot on my system, added --shell-escape and --enable-write18 to my pdflatex configuration, but the error persisted.  I'm completely out of ideas. Please, help me.
Im trying to run the following code  \documentclass[border=10pt]{standalone} \usepackage{pgfplots} \pgfplotsset{width = 7cm, compat = 1.8} \begin{document} \begin{tikzpicture} \begin{axis}[domain = -2:2, domain y = 0:2*pi] \addplot3[contour gnuplot = {output point meta = rawz, number=10, labels=false}, samples = 41, z filter/.code=\def\pgfmathresult{-1.6}] {exp(-x^2) * sin(deg(y))}; \addplot3[surf, samples = 25] {exp(-x^2) * sin(deg(y))}; \end{axis} \end{tikzpicture} \end{document}   and I'm getting the error  Package pgfplots Error: sorry, plot file{Utitlled_contourmp0.table} could not be opened   through a quick search I found out that contour maps require pgfplots and gnuplot to talk to each other. In theory the way to make them interact is adding  !TEX option = --enable-write18   or   %!TEX option = --enable-escape   at the top of the file. Unfortunately this has not worked for me. Any suggestions?
Which damage dice exactly does the Great Weapon Fighting fighting style allow you to reroll? I am a citizen of two different countries, and have two passports.  How should I use my passports when traveling? Novel about a teleportation device and a con artist alien I read two (maybe three) books about a protagonist who communicates with an alien who provides the instructions on how to create a device to teleport. The device is flawed in that it purposefully uses more energy (much more) by taking it from the rotation of the Earth.  The main character and two others continue to fight, commit intrigue, etc. The alien then uses them to recruit other races to do the same thing. Let's suppose I'm a wizard casting a ranged spell. An enemy is behind cover but I suspect he'll come out, so I ready an action to cast at him when he comes out; but I don't want to risk getting charged at by another enemy and losing concentration or taking disadvantage. Can I say:  "I ready a spell. When that guy over there leaves cover, or when any enemy gets within 5 feet of me, I will cast it on that enemy"? 'Guest' vs 'Guest User License' in sites? How to escape quotes in shell? I've just updated to the latest Google Chrome Dev build, and they've changed from the annoying-but-ok new tab page to an ugly and less usable page.  On the old one, nine thumbnails was not enough, and now they've restricted it to eight.  There's an empty "Tips and Suggestions" box which I wouldn't want even if it had stuff in; they've added Recent Downloads - on the rare occasions when I need that, I'll hit Ctrl-J to open the Downloads tab; and the site-specific search box on the right has now gone!  Is there a way to get the old new tab page back, or a plugin to provide a superior one?   Update: I launch Chrome by pressing Win+R and entering "chrome" - I have a shortcut on the Path with a Target of "C:\Documents and Settings\&lt;user&gt;\Local Settings\Application Data\Google\Chrome\Application\chrome.exe" --old-new-tab-page and whilst double-clicking this shortcut brings up the previous new tab page, using the keyboard method results in the old one.  How do I get it working via the Run box? (Without using a batch file, which slows things down too much.)  Update 2: GRRR! Now they've gone and stopped the --old-new-tab-page parameter from working at all! I hate this new version of the page that they're forcing upon us - can anyone provide a method to get rid of it and get the decent page back? How can I convert ereg expressions to preg in PHP? If you have two envelopes, and ... Suppose you're given two envelopes. Both envelopes have money in them, and you're told that one envelope has twice as much money as the other. Suppose you pick one of the envelopes. Should you switch to the other one?  Intuitively, you don't know anything about either envelope, so it'd be ridiculous to say that you should switch to the other envelope to maximize your expected money.   However, consider this argument. Let $x$ be the amount of money in the envelope you picked. If $y$ is the amount of money in the other envelope, then the expected value equals  $$E(y) = \frac{1}{2}\left(\frac{1}{2}x\right) + \frac{1}{2}\left(2x\right) = \frac{5}{4} x$$  But $5x/4 &gt; x$, so you should switch!    The Wikipedia article says that $x$ stands for two different things, so this reasoning doesn't work. I say this is not a valid resolution.   Consider opening up the envelope that you pick, and finding $\$10$ inside. Then you can run the expected value calculation to get $$E(y) = \frac{1}{2} \cdot \$5+\frac{1}{2} \cdot \$20 = \$12.50$$  This means that if you open one of the envelopes and find $\$10$, you should switch to the other envelope. The $\$10$ doesn't stand for two different things, it literally just means $\$10$.   But you don't have to open up the envelope to run this calculation, you can just imagine what's inside, and run the calculation based on that. This is what "Let $x$ be the amount in the envelope" means. The problem with the argument is not that $x$ stands for two different things.   So what is the problem?    Previous questions on stack exchange have given the resolution that I just said I wasn't satisfied by, so please don't mark this as a duplicate. I want a different resolution, or a more satisfying explanation of why $x$ does stand for two different things.  Apparently there is still research being published about this problem - maybe it isn't so obvious?    I think there's something subtle wrong with the premise. Because there's no uniform probability distribution on $\mathbb{R}$, statements like "random real number" are not well-defined. Likewise, I think "one envelope has twice as much money as the other" assumes some probability distribution on $\mathbb{R}$, and perhaps our expected value calculation assumes that this distribution is uniform, which it cannot be ... Digitizing Free Satellite Imagery in QGIS without getting Alignment issues with Openlayers Plugin Every subspace of a vector space has a complement I want to see if my proof is true or I thought very trivially?    If $H$ is a subspace of a finite dimensional vector space $V$, show there is a subspace $K$ such that $H\cap K=0$ and $H+K=V$    So far I have tried :    $H\subseteq V$ is a subspace $\Rightarrow\,\exists\;K=(V-H)\subseteq V$ $K$ is a subspace because it's the sum of two subspace $V$ and $(-H)$ Now we should prove that $H\cap K=0$ We assume $H\cap K\neq0\Rightarrow\exists\,\vec u\neq0\,,\,\vec u\in H\cap K$ $\vec u\in H\cap K\Rightarrow \begin{cases}\vec u\in H\\\vec u\in K\,\Rightarrow\vec u\in V-H\Rightarrow\vec u\in V,\,\vec u\notin H\end{cases}$ That's a contradiction so our hypothesis was wrong and $\vec u=0$ A random variable that induces a $\sigma$-algebra the same as the one in the sample space I have browsed several ASIC manufacturer's webs, but I haven't found an actual number. I assume there would be a fixed cost associated with creating masks and such and then there will be a cost per unit.     Note: that I don't actually want to have an ASIC made, I'm just curious. I'm testing something in Oracle and populated a table with some sample data, but in the process I accidentally loaded duplicate records, so now I can't create a primary key using some of the columns.  How can I delete all duplicate rows and leave only one of them? Disallow downvoting other answers if I've posted my own Possible Duplicates:        As Dan Dyer mentioned in his comment on , there is a conflict of interest when you have posted your own answer and are allowed to downvote other answers.  Despite the vote editing window being drastically reduced, the fundamental problem remains: I can downvote the other answers permanently and still benefit - my answer gets upvoted ONCE and wham, I have just made up the rep loss for my 10 other downvotes. The vote editing window fixes part of the problem, but there is a more complete fix that has the extra benefit of not preventing legitimate vote changes: to disallow downvotes on competing answers when you have posted one yourself.  The temptation to wrongfully downvote competing answers is huge. The rep loss is tiny in comparison. It has to be in order for people to continue to legitimately downvote.  Details:   If I have previously voted and then post my own answers, delete my downvotes. Continue to allow me to remove the upvotes - I think this is fully legitimate. If I delete my answer it's probably best to continue to deny downvotes (perhaps even including the question), but I don't have a strong opinion either way. Using relative paths for Windows shortcuts Where can I ask questions about the computer problems I have been facing?  Current problems I am facing with my computers:   Windows 7 errors random "Blue screens of Death" computer randomly freezing up Xfire challenges Java method dispatch with null argument Install Biber in MiKTeX on a 64-bit version of Windows Update: As of summer 2015 Biber is also included in the 64-bit repositories for MikTeX. There is no need to install Biber manually any more, it can simply be installed via the Package Manager just like other packages.   The question  describes how to use Biber with MiKTeX. But on the 64-bit version of MiKTeX Biber isn't installed.  How it is possible to install Biber on a 64-bit version of Windows?  Can I use this ? Should I really have been awarded mortarboard on a Per-site meta?