In the beginning I want to ask why matrix is messed up in beamer, then @percusse gave the instructions to make it perform right.  Now the problem left is the two arrows before c4 and c7 seems not horizontal, is there a way to fixt it?    \documentclass{standalone} %\documentclass{beamer} \usepackage{tikz} \usetikzlibrary{matrix} \begin{document} %\begin{frame}[fragile] \begin{tikzpicture}   \matrix (m) [matrix of math nodes,row sep=3em,column sep=4em,minimum width=2em]   {       c_0 &amp; c_1 &amp; c_2 &amp; c_3 \\       {} &amp; c_4 &amp; c_5 &amp; c_6 \\       {} &amp; c_7 &amp; c_8 &amp;     &amp;     \\   };    \path[-stealth]       (m-1-1) edge node [above] {$a_0$} (m-1-2)       (m-1-2) edge node [above] {$a_1$} (m-1-3)       (m-1-3) edge node [above] {$a_2$} (m-1-4)       (m-2-1) edge node [above] {$a_3$} (m-2-2)       (m-2-2) edge node [above] {$a_4$} (m-2-3)       (m-2-3) edge node [above] {$a_5$} (m-2-4)       (m-3-1) edge node [above] {$a_6$} (m-3-2)       (m-3-2) edge node [above] {$a_7$} (m-3-3); \end{tikzpicture} %\end{frame} \end{document}
I am having trouble getting a basic example of a matrix of notes to show up in my beamer presentation. I am using the code copied from the pgf manual. Here is a complete working example. The error I get upon compilation is:  "Package pgfbasematrix Error: Single ampersand used with wrong catcode."  \documentclass{beamer} \usepackage{tikz} \usetikzlibrary{arrows,decorations.pathmorphing,backgrounds,fit,petri,positioning,matrix}  \begin{document}  \begin{frame}  \begin{tikzpicture} \matrix (magic) [matrix of nodes] { 8 &amp; 1 &amp; 6 \\ 3 &amp; 5 &amp; 7 \\ 4 &amp; 9 &amp; 2 \\ }; \draw[thick,red,-&gt;] (magic-1-1) |- (magic-2-3); \end{tikzpicture}  \end{frame} \end{document}
What to do when my 3-year-old holds poop in and won't go in diaper or on potty? Travel to Ireland (Dublin) with U.K. Visitor visa Can someone explain how combinatorial proofs work?  I've included an example questions that's been giving me a hard time.  Any insight on the topic would be great.  $$\sum_{k=1}^{n}k{n \choose k} = n2^{n-1}$$  Another one:  $${2n \choose 2} = 2{n \choose 2} + n^2$$  The solution says:  LHS: Pick two people from a pool of n men and n women. RHS: Pick two women, pick two men, and pick one of each.  But I don't see how this applies.  How does $n^2$ show that we're picking "one of each?"  Thanks for the help :) My understanding of the Stern–Gerlach experiment is that neutral (0 total charge) particles are sent through a non-homogeneous magnetic field, with the expectation that the field will push that particle's path higher or lower on a detector because of the collective spin of that particle. While the detector can detect particles in a two-dimensional surface, the results of the experiment are that particles appear in only two localized areas directly above the path of the particle stream, or directly below the path of the particle stream - spin up or spin down. The conclusions from these measurements are that the particle, when measured, will always have about the same magnitude.  Why does this not follow from classical mechanical theory related to magnetism? If you shot a magnet through a similar apparatus, I would expect the magnet to be rotated to align with the magnetic field in some way which, at high enough field strengths relative to the mass of the magnet, would cause us to measure basically the same magnitude as if the magnet entered the apparatus pre-aligned with the field.  How is my explanation incorrect? Kubuntu - can not enter wifi credentials after adding external wifi card My ethernet connection is quite unreliable (It uses powerline adapters) so I bought an external wifi adapter. I have plugged it in and run the command sudo ip address add 192.168.0.39/24 brd + dev enp7s0, and KDE has detected it. Unfortunately, it doesn't seem to realise it is a wireless network and therefore needs credentials. Where I could normally find a place to enter credentials (the network widget, system settings) there are none. KDE reports that the device is connected in the UI. How do I make it work out that it is wireless and therefore needs credentials? Edit: With ethernet plugged out, (USB) adapter plugged in: $ ip address show 1: lo: &lt;LOOPBACK,UP,LOWER_UP&gt; mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00     inet 127.0.0.1/8 scope host lo        valid_lft forever preferred_lft forever     inet6 ::1/128 scope host         valid_lft forever preferred_lft forever 2: enp7s0: &lt;NO-CARRIER,BROADCAST,MULTICAST,UP&gt; mtu 1500 qdisc fq_codel state DOWN group default qlen 1000     link/ether 04:d9:f5:8a:f5:e0 brd ff:ff:ff:ff:ff:ff  With ethernet plugged in, adapter plugged in: 1: lo: &lt;LOOPBACK,UP,LOWER_UP&gt; mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00     inet 127.0.0.1/8 scope host lo        valid_lft forever preferred_lft forever     inet6 ::1/128 scope host         valid_lft forever preferred_lft forever 2: enp7s0: &lt;BROADCAST,MULTICAST,UP,LOWER_UP&gt; mtu 1500 qdisc fq_codel state UP group default qlen 1000     link/ether 04:d9:f5:8a:f5:e0 brd ff:ff:ff:ff:ff:ff     inet 192.168.0.51/24 brd 192.168.0.255 scope global dynamic noprefixroute enp7s0        valid_lft 863988sec preferred_lft 863988sec     inet6 fe80::7eb1:eca2:96a0:fe5c/64 scope link noprefixroute         valid_lft forever preferred_lft forever  With just ethernet: 1: lo: &lt;LOOPBACK,UP,LOWER_UP&gt; mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00     inet 127.0.0.1/8 scope host lo        valid_lft forever preferred_lft forever     inet6 ::1/128 scope host         valid_lft forever preferred_lft forever 2: enp7s0: &lt;BROADCAST,MULTICAST,UP,LOWER_UP&gt; mtu 1500 qdisc fq_codel state UP group default qlen 1000     link/ether 04:d9:f5:8a:f5:e0 brd ff:ff:ff:ff:ff:ff     inet 192.168.0.51/24 brd 192.168.0.255 scope global dynamic noprefixroute enp7s0        valid_lft 863960sec preferred_lft 863960sec     inet6 fe80::7eb1:eca2:96a0:fe5c/64 scope link noprefixroute         valid_lft forever preferred_lft forever  With nothing: 1: lo: &lt;LOOPBACK,UP,LOWER_UP&gt; mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00     inet 127.0.0.1/8 scope host lo        valid_lft forever preferred_lft forever     inet6 ::1/128 scope host         valid_lft forever preferred_lft forever 2: enp7s0: &lt;NO-CARRIER,BROADCAST,MULTICAST,UP&gt; mtu 1500 qdisc fq_codel state DOWN group default qlen 1000     link/ether 04:d9:f5:8a:f5:e0 brd ff:ff:ff:ff:ff:ff  lsusb, adapter plugged in: Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 003 Device 002: ID 046d:c31c Logitech, Inc. Keyboard K120 Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 001 Device 003: ID 1d57:32da Xenta 2.4GHz Receiver (Keyboard and Mouse) Bus 001 Device 004: ID 0bda:b812 Realtek Semiconductor Corp. 802.11ac NIC Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub  I'm not adding it with it plugged out because it's obviously the Bus 001 Device 004: ID 0bda:b812 Realtek Semiconductor Corp. 802.11ac NIC. There were no restarts between any of these changes. I am running QGIS 2.18.14 (QGIS code revision: ff83b9a479) on a windows 7 machine, it comes with GRASS 7.2.2 (Code Revision r71496), but it does not come with r.in.lidar. I have noticed QGIS 2.18.16.1 has the same problem and it shares the same GRASS 7.2.2 (Code Revision r71496).  I know there were some issues with it and later solved as I read , I also certailny used it short ago in 2017, so I wonder which version should I go for before starting the always risky attempt of a new installation. Particularly, what is the best snippets package out there?  Features:   easy to define new snippets (plain text, custom input with defaults) simple navigation between predefined positions in the snippet multiple insertion of the same custom input accepts currently selected text as a custom input cross-platform (Windows, Linux) dynamically evaluated expressions (embedded code) written in a concise programming language (Perl, Python, Ruby are preferred) nicely coexists with others packages in Emacs   Example of code template, a simple for loop in C:  for (int i = 0; i &lt; %N%; ++i) {   _ }   It is a lot of typing for such common code. I want to invoke a code template or snippet which inserts that boilerplate code for me. Additionally it stops (on TAB or other keystroke) at %N% (my input replaces it) and final position of the cursor is _. Epson LX-310 not working after Cumulative Update 2017-11 Windows 10 I have Windows 10 Pro x32 and an Epson LX-310 printer that was working. Yesterday, Windows 10 automatically updated with 2017-11 Cumulative Update for Windows 10.   Today, I cannot print. The printer status is on. When I click "Print a test page", it quickly says the test page has been sent but the printer does not print it.   My printer is connected to a USB port. What wrong with my Windows 10? Plot Option Precedence while combining Plots with Show[] Correct usage of "lest" I'm a fan of extension methods in C#, but haven't had any success adding an extension method to a static class, such as Console.  For example, if I want to add an extension to Console, called 'WriteBlueLine', so that I can go:  Console.WriteBlueLine("This text is blue");   I tried this by adding a local, public static method, with Console as a 'this' parameter... but no dice!      public static class Helpers {     public static void WriteBlueLine(this Console c, string text)     {         Console.ForegroundColor = ConsoleColor.Blue;         Console.WriteLine(text);         Console.ResetColor();     } }   This didn't add a 'WriteBlueLine' method to Console... am I doing it wrong? Or asking for the impossible? I'm trying to delete some old flow which are inactive via workbench. DestructiveChanges.xml &lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot;?&gt; &lt;Package xmlns=&quot;http://soap.sforce.com/2006/04/metadata&quot;&gt;     &lt;types&gt;         &lt;members&gt;Advanced_Round_Robin&lt;/members&gt;         &lt;name&gt;Flow&lt;/name&gt;     &lt;/types&gt;Ï &lt;/Package&gt;  package.xml &lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot;?&gt; &lt;Package xmlns=&quot;http://soap.sforce.com/2006/04/metadata&quot;&gt;       &lt;version&gt;48.0&lt;/version&gt; &lt;/Package&gt;  I've added both file in zip and in workbench when I deploy using this zip file I get below error.  insufficient access rights on cross-reference id   What permission I need to have to perform this action? Also is there way I can delete few version of same flow only? Like keep only last 3-4 version and delete all previous version of given flow? Thank you. Altium de-highlighting nets after using 'Find Similar Objects...' command What does "...from nonmagical attacks not made with silvered weapons" mean? Spoilers Alert!!!      Bran sees that Jon is the son of Lyanna at Tower of Joy.   However, People of the north won't just believe words.  Howland Reed was with Eddard at the tower, Eddard is dead, but Howland could be alive. Even if Howland Reed comes forth and tells Jon's true lineage. It will still be just words.   Why would the people believe the words of a child and an old man? What happens to a Devil when its alignment is forcibly changed? According to PHB 122, in the section entitled Alignment in the Multiverse, for most creatures, "alignment is a moral choice." Myth says good-aligned gods created the races that are free to choose to be evil (they have free will), while evil-aligned gods created the races that are very inclined towards evil, since they were born to serve the evil god in the first place.  However, there are some types of creatures -- like devils -- which embody an alignment in its essence:     Alignment in the Multiverse, PHB 122      A devil does not choose to be lawful evil, and it doesn't tend toward lawful evil, but rather it is lawful evil in its essence. If it somehow ceased to be lawful evil, it would cease to be a devil.   My first thought was to not take this reading literally. The text could have meant that a neutral evil devil "isn't really a devil," but really, it's still a devil. It's a bit like imagining a guitarist who loses both hands. The loss of some part of a person's essence makes them not the same person anymore.  However, keeping my attention on it, I'm finding this text more and more difficult to interpret. If a devil "is lawful evil in its essence" then what does it mean when "it would cease to be a devil"? What happens to a devil when its alignment is forcibly changed?  There are , and a devil can be subject to some of them. com.google.android.trichromelibrary causes many Android apps to crash Why does "unisex" mean both sexes? There are some places where men and women are segregated — for example public toilets and public swimming pool changing areas.  By this I mean, for example, that there are "Men's toilets" and "Ladies' toilets".  However, in some more cosmopolitan swimming baths, and other places, there are such things as unisex changing areas, or unisex toilets.  From my understanding uni- implies one, as in universe, unilateral or unicycle.  However when it comes to unisex, this means both sexes, so applies to two things.  How does uni- mean one in unisex? Does it mean one? Redirect, Change URLs or Redirect HTTP to HTTPS in Apache - Everything You Ever Wanted to Know About mod_rewrite Rules but Were Afraid to Ask This is a  about Apache's mod_rewrite.   Changing a request URL or redirecting users to a different URL than the one they originally requested is done using mod_rewrite. This includes such things as:   Changing HTTP to HTTPS (or the other way around) Changing a request to a page which no longer exist to a new replacement. Modifying a URL format (such as ?id=3433 to /id/3433 ) Presenting a different page based on the browser, based on the referrer, based on anything possible under the moon and sun. Anything you want to mess around with URL   Everything You Ever Wanted to Know about Mod_Rewrite Rules but Were Afraid to Ask!  How can I become an expert at writing mod_rewrite rules?   What is the fundamental format and structure of mod_rewrite rules? What form/flavor of regular expressions do I need to have a solid grasp of? What are the most common mistakes/pitfalls when writing rewrite rules? What is a good method for testing and verifying mod_rewrite rules? Are there SEO or performance implications of mod_rewrite rules I should be aware of? Are there common situations where mod_rewrite might seem like the right tool for the job but isn't? What are some common examples?   A place to test your rules  The  web site is a great place to play around with your rules and test them. It even shows the debug output so you can see what matched and what did not. Adding word 'Table' before each entry in list of tables I need to prefix each entry in list of tables and figures with appropriate text - table or figure for each. Also I need to remove chapter numbers from list, because tables are numbered consequently through the whole report.  I managed to do everyting I need with this simple commands:  \renewcommand{\thetable}{\arabic{table}} \renewcommand{\thefigure}{\arabic{figure}}  \makeatletter \providecommand\phantomsection{}% for hyperref  \newcommand\listoftablesandfigures{%     \chapter*{List of Tables and Figures}%     \phantomsection %\addcontentsline{toc}{chapter}{List of Illustrations}% %\section*{Figures}% %\phantomsection %\addcontentsline{toc}{section}{\protect\numberline{}Figures}% \@starttoc{lof}% \bigskip %\section*{Tables}% %\phantomsection %\addcontentsline{toc}{section}{\protect\numberline{}Tables}% \@starttoc{lot}} \makeatother   Now only one thing remains: to be consistent with text in list of tables and figures.