Pass in local variable to callback function
JavaScript closure inside loops – simple practical example
How to find chromatic number of the $n$-dimensional hypercube $Q_n$? How can I tell if an AC adapter is compatible with my laptop? Possible Duplicate:        How can I tell if an AC adapter is compatible with my laptop?  For example, does the voltage output have to bee the same, or just close?  What power measurements matter? The very common beginner mistake is when you try to use a class property "statically" without making an instance of that class. It leaves you with the mentioned error message:     You can either make the non static method static or make an instance of that class to use its properties.   Why? I am not asking for solutions. I would be grateful to know what is the reason behind it. The very core reason!  private java.util.List&lt;String&gt; someMethod(){     /* Some Code */     return someList;             }  public static void main(String[] strArgs){                // The following statement causes the error. You know why..     java.util.List&lt;String&gt; someList = someMethod();          } When drawing a line between two nodes in TikZ, you can specify the anchors on the beginning and end nodes in order to control how the line is drawn.  I would like to specify the anchor on the beginning node, and the angle at which the line is drawn, and let TikZ figure out where it will intercept the end node.  The usual use case is when I'm connecting to a "big node" and I would like the lines to be vertical.  I can cheat by placing a coordinate behind the big node, drawing a line to the coordinate instead, and then drawing the big node so that it covers things up.  However this won't work if I need to put an arrow on the end.  I could try to calculate the intercept coordinate on the edge of the big node manually, but that seems against the TikZ spirit.  |- doesn't work in this case.  \documentclass[10pt]{minimal} \usepackage[active,tightpage,pdftex]{preview} \usepackage{tikz}  \begin{document} \begin{preview}  \tikzstyle{RectObject}=[rectangle,fill=white,draw,line width=0.5mm] \tikzstyle{line}=[draw] \tikzstyle{arrow}=[draw, -latex]   \begin{tikzpicture}   %%%%%%%%%%%%%%%%%%%%%%%%   %%  LEFT SIDE   %%%%%%%%%%%%%%%%%%%%%%%%   \draw (1,0) node[RectObject] (Small1A) {A};   \draw (3,0) node[RectObject] (Small1B) {B};   \coordinate (Cheat1A) at (1,2);   \coordinate (Cheat1B) at (3,2);   \path [line] (Small1A.north) -- (Cheat1A);   \path [line] (Small1B.north) -- (Cheat1B);    % need to draw Big Node last to cover up our cheating   \draw (2,2) node[RectObject, inner xsep=1cm] (Big1) {Big Node};    \draw (2,4) node[text width=4cm] (text1) {L: Cheating to control line orientation. Arrows would be hard.};    %%%%%%%%%%%%%%%%%%%%%%%%   %%  RIGHT SIDE   %%%%%%%%%%%%%%%%%%%%%%%%   \draw (7,2) node[RectObject, inner xsep=1cm] (Big2) {Big Node};   \draw (6,0) node[RectObject] (Small2A) {A};   \draw (8,0) node[RectObject] (Small2B) {B};   \path [arrow] (Small2A) -- (Big2);   \path [arrow] (Small2B) -- (Big2);    \draw (7,4) node[text width=4cm] (text2) {R: No cheating. Arrows easy. Can't control line orientation.}; \end{tikzpicture} \end{preview} \end{document}   Here's a side-by-side example of "cheating", which shows what I want to be able to do, and "not cheating", which does not do what I want.    The left side of this example shows what I want to be able to do, except I want to do it without cheating, and I'd like to put arrows on the end of the lines. Can't install Oracle JDK 9 I uninstalled jdk packages and now can't install them back. I managed to install oracle-java7-installer and oracle-java8-installer but can't install oracle-java9-installer. It seems that my computer tries to download wrong version of oracle-java9-installer 177 when version i would be able to download is 178.    $ wget http://download.java.net/java/jdk9/archive/178/binaries/jdk-9+178_linux-x64_bin.tar.gz --2017-07-21 11:00:02--  http://download.java.net/java/jdk9/archive/178/binaries/jdk-9+178_linux-x64_bin.tar.gz Connecting to 10.144.1.10:8080... connected. Proxy request sent, awaiting response... 200 OK Length: 293348142 (280M) [application/x-gzip] Saving to: 'jdk-9+178_linux-x64_bin.tar.gz'  jdk-9+178_linux-x64_bin.tar.gz     1%[&gt;                                                          ]   5.42M  5.04MB/s               ^C  $ wget http://download.java.net/java/jdk9/archive/177/binaries/jdk-9+177_linux-x64_bin.tar.gz --2017-07-21 11:00:16--  http://download.java.net/java/jdk9/archive/177/binaries/jdk-9+177_linux-x64_bin.tar.gz Connecting to 10.144.1.10:8080... connected. Proxy request sent, awaiting response... 404 Not Found 2017-07-21 11:00:17 ERROR 404: Not Found.   Can you help? apt-get tries to install Oracle JDK 9.  I run Ubuntu 16.04 in virtual machine hosted by win7  Full error message:  sudo apt-get install oracle-java9-installer Reading package lists... Done Building dependency tree        Reading state information... Done oracle-java9-installer is already the newest version (9b177-1~webupd8~0). 0 upgraded, 0 newly installed, 0 to remove and 147 not upgraded. 1 not fully installed or removed. After this operation, 0 B of additional disk space will be used. Do you want to continue? [Y/n] Y Setting up oracle-java9-installer (9b177-1~webupd8~0) ... Using wget settings from /var/cache/oracle-jdk9-installer/wgetrc Downloading Oracle Java 9... --2017-07-21 10:54:11--  http://download.java.net/java/jdk9/archive/177/binaries/jdk-9+177_linux-x64_bin.tar.gz Connecting to 10.144.1.10:8080... connected. Proxy request sent, awaiting response... 404 Not Found 2017-07-21 10:54:13 ERROR 404: Not Found.  download failed Oracle JDK 9 is NOT installed. dpkg: error processing package oracle-java9-installer (--configure):  subprocess installed post-installation script returned error exit status 1 Errors were encountered while processing:  oracle-java9-installerE: Sub-process /usr/bin/dpkg returned an error code (1) Order of finite fields is $p^n$ Let $F$ be a finite field. How do I prove that the order of $F$ is always of order $p^n$ where $p$ is prime? Baker-Hausdorff Lemma from Sakurai's book I'd like to show that, given to hermitian operators $A,G$ on a Hilbert space $\mathscr{H}$, the following identity holds: $$ e^{iG\lambda}A e^{-iG\lambda} = A + i\lambda [G,A] + \frac{\left(i\lambda\right)^2}{2!}[G,[G,A]]+\ldots+\frac{(i\lambda)^n}{n!}\underbrace{[G,[G,[G,\ldots[G}_{n\ times},A]]]\ldots]+\ldots $$ where $\lambda$ denotes a real parameter and $[\ \!,]$ indicates the commutator.  This is a proof left to the reader by Sakurai in his books on Modern Quantum Mechanics. Show that if $a \equiv b \pmod n$, $\gcd(a,n)=\gcd(b,n)$ Concave implies subadditive Trouble with proving $A$ is an integrally closed domain $\Rightarrow$ $A[t]$ is integrally closed domain What could cause touch to fail with this error message?  touch: cannot touch `foo': No such file or directory   Note that an error due to incorrect permissions looks different:  touch: cannot touch `foo': Permission denied Is just after your PhD a good time to switch your research area? I am finishing my PhD soon. The area in which I pursued my PhD is very challenging as I was only able to publish couple of papers even after spending many years. I want to switch into other research are due these reasons   to attract more students  to be comfortable to do research (along with teaching, I should be able to do research)   Even though I like the research I am doing right now, I seem to be isolated in my university. If ten students join my university for a PhD, hardly one student takes this area. My research area is not like machine learning or deep learning etc, so researchers of my domain are also not that much interested in my work.   The thing is I can work different research area but: Is this the right time? I am heading to a post-doc and learning a new area will probably take several months. Although my switch is not 180 degree, I am still worried. Playing Minecraft on Windows 10, owning a Xbox One disc I own a Minecraft disc for an Xbox One, and would like to play on my PC (ultimately, playing with others who will be on the Xbox).  I'm not too familiar with the Xbox account ecosystem, and with dozen different Minecraft editions, I'm lost as to how I can do that. Does someone falling into a black hole see the end of the universe? This question was prompted by . Notoriously, if you calculate the Schwarzschild coordinate time for anything, matter or light, to reach the event horizon the result is infinite. This implies that the universe ages by an infinite time before someone falling into the black hole reaches the event horizon, so could that person see the universe age by an infinite time?  To be more precise, suppose the observer starts falling from rest at time $t = 0$ and some initial distance $r &gt; r_s$. If we wait for some time $T$ then shine a light ray at the falling observer. Will the light ray always reach the falling observer before they cross the event horizon? If not, what is the formula for the longest time $T$ that we can wait and still be sure the ray will catch the observer? If $T$ is not bounded it implies that observer could indeed see the end of the universe.  I can think of a qualitative argument for an upper limit on $T$, but I'm not sure how sound my argument is. The proper time for the observer to fall to the event horizon is finite - call this $\tau$. The proper time for the light ray to reach the horizon is zero, therefore the light ray will reach the observer before they cross the event horizon only if $T &lt; \tau$. Hence $T$ is bounded and the observer won't see the end of the universe.  I think a more rigorous approach would be to determine the equations of motion (in the Schwarzschild coordinates) for the falling observer and the light ray, and then find the condition for the light to reach the falling observer at some distance $\epsilon$ from the event horizon. Then take the limit as $\epsilon \rightarrow 0$. In principle this seems straightforward, but in practice the algebra rapidly defeated me. Even for a light ray the radial distance:time equation isn't closed form (Wolfram claims it needs the $W$ function) and for the falling observer the calculation is even harder. Is it possible to get rid of the bullets in the miniframes outer theme Definite integral, quotient of logarithm and polynomial: $I(\lambda)=\int_0^{\infty}\frac{\ln ^2x}{x^2+\lambda x+\lambda ^2}\text{d}x$ I was thinking this integral : $$I(\lambda)=\int_0^{\infty}\frac{\ln ^2x}{x^2+\lambda x+\lambda ^2}\text{d}x$$ What I do is use a Reciprocal subsitution, easy to show that: $$I(\lambda)=\int_0^{\infty}\frac{\ln ^2x}{\lambda ^2x^2+\lambda x+1}\text{d}x =\frac{1}{\lambda}\int_0^{\infty}\frac{(\ln x-\ln \lambda)^2}{x^2+x+1}\text{d}x \\ =\frac{\ln ^2\lambda}{\lambda}\int_0^{\infty}\frac{1}{x^2+x+1}\text{d}x+\frac{1}{\lambda}\int_0^{\infty}\frac{\ln ^2x}{x^2+x+1}\text{d}x \\ =\frac{\ln ^2\lambda}{\lambda}\frac{2\pi}{3\sqrt{3}}+\frac{2}{\lambda}\int_0^1\frac{\ln ^2x}{x^2+x+1}\text{d}x$$ But I hav no idea on process the remaining integral:( Anyone knows how to solve it?  THX guys! I came with another method might work for this: Recall the handy GF $$\frac{1}{x^2+x+1}=\frac{2}{\sqrt{3}}\sum_{k=0}^{\infty}\sin \left(\frac{2\pi}{3}\left(k+1\right)\right)x^k$$ Then we have :  $$\int_0^1\frac{\ln ^2x}{x^2+x+1}\text{d}x=\frac{2}{\sqrt{3}}\sum_{k=0}^{\infty}\frac{2}{\left(k+1\right)^3}\sin \left(\frac{2\pi}{3}\left(k+1\right)\right)x^k$$ With $$\sum_{k=1}^{\infty}\frac{\sin (kx)}{k^3}=\frac{\pi ^2}{6}x-\frac{\pi}{4}x^2+\frac{x^3}{12}$$ What can we arrived? Possible Duplicate:        When I click 'Unanswered' in the menubar, I get a list of questions, all of which have been answered. Does it just mean there's no accepted answer? If so, can we make that more obvious? Can we get some way of finding really unanswered questions? How can I prove the Carmichael theorem I am trying to prove that these two definitions of Carmichael function are equivalent.  I am using this definition of Carmichael function:     $\lambda(n)$ is the smallest integer  such that $k^{\lambda(n)}\equiv1 \pmod n\,$ $\forall  k$ such that $\gcd(k,n)=1$.   to prove this one:     $\lambda(n) = \begin{cases}\phi(p^a) &amp; (p=2\text{ and }a\le 2)\text{ or }(p\ge 3)\\\dfrac 1 2 \phi{(2^a)}  &amp; a\ge 3\\ \text{lcm}\left((\lambda(p_1^{a_1}),\cdots,\lambda(p_k^{a_k})\right)&amp; \text{for }n=\prod_{i=1}^k p_i^{a_i} \end{cases}$   Since $a^{\lambda(n)}\equiv 1 \pmod n$,  and $a^{\lambda(m)}\equiv1 \pmod m$ with $\gcd(m,n)=1 \implies a^{\text{lcm}({\lambda(n)},\lambda(m)}\equiv1 \pmod {nm} $   Hence $\lambda (mn)=\text{lcm}(\lambda(n), \lambda(n))$ for $m$ and $n$ coprime to each other.  How can I prove the other relations? Convergence of $A_nT$ to $AT$ in operator norm for compact $T$ $A_n:Y\rightarrow Z$ are operators that strongly converge to $A$. Also, $\|A_n\|_\text {op}\le c$ for $c&gt;0$. Given a compact operator $T:X\rightarrow Y$, I need to show that $A_nT$ converges to $AT$ in operator norm (all spaces in this question are Banach spaces).     I was unable to prove this and I also do not understand why we need to assume that $T$ is compact. Any ideas? tcolorbox manual tip box, how to clone?