Go to do apt-get update and it can't find anything. 403 and 404 errors. Go to us.archive.ubuntu.com/ubuntu/dists/ and there is no disco there.
Recently I have installed an older version of Ubuntu on my old machine. Whenever I try to install any software, I get an error saying it couldn't be found:  $ sudo apt-get install vlc Reading package lists... Done                Building dependency tree        Reading state information... Done     E: Couldn't find package vlc
Can I have too many mods? I found a lot of mods that make thinks lighter, and add mark and recall, and a basement I like. They are all on Steam, and what I want to know is if I can have too many? Will they all work together? Or should I just leave them alone? Prove that a non-empty closed convex $S$ has an extreme point iff it does not contain any line I am wondering how to prove the following theorem: Let $S \subset \mathbf{R}^{n}$ be a non-empty closed convex set. Then $S$ has at least one extreme point iff $S$ does not contain any line. Extreme point $x \in S$ means that there is no couple of points $y, z \in S$ and $\lambda \in (0;1)$ such that $x = \lambda y + (1-\lambda)z$. I know that every non-empty closed convex set can be represented as an intersection of all closed half-spaces containing the set but I do not know if it is helpful in proving the theorem. C++ catching all exceptions Is there a c++ equivalent of Java's  try {     ... } catch (Throwable t) {     ... }   I am trying to debug Java/jni code that calls native windows functions and the virtual machine keeps crashing.  The native code appears fine in unit testing and only seems to crash when called through jni.  A generic exception catching mechanism would prove extremely useful. Why Does Harry Have a Scar When Avada Kedavra Leaves No Trace? Why does Harry have a scar when Avada Kedavra leaves no trace?     ‘The Muggle authorities were perplexed. As far as I am aware, they do not know to this day how the Riddles died, for the Avada Kedavra Curse does not usually leave any sign of damage ... the exception sits before me,’ Dumbledore added, with a nod to Harry’s scar.   Half-Blood Prince - page 343 - Bloomsbury - chapter 17, A Sluggish Memory   What caused Harry to retain a scar from Avada Kedavra, when no one else in know history showed any signs of cause of death when Avada Kedavra was used?  What caused Harry's scar?  I'd love an answer based in canon, such as the books, interviews with J.K. Rowling, or Pottermore. Among any three consecutive positive integers one is a multiple of 3 How to hide the [@] in a Minecraft command block Entering and leaving the UK on the day of visa expiry C++ STL Vector Iterator accessing members of an Object I think I've declared a Vector with an object correctly.  But, I don't know how to access it's members when looping with Iterator.  In my code, the line --->>  cout &lt;&lt; " " &lt;&lt; *Iter;  How do I print the contents of the members?  Like *Iter.m_PackLine ???  Not sure if I used the correct terminology, but appreciate the help!  Thanks  class CFileInfo {   public:       std::string m_PackLine;       std::string m_FileDateTime;       int m_NumDownloads; };  void main() {   CFileInfo packInfo;    vector&lt;CFileInfo, CFileInfo&amp;&gt; unsortedFiles;   vector&lt;CFileInfo, CFileInfo&amp;&gt;::iterator Iter;    packInfo.m_PackLine = "Sample Line 1";   packInfo.m_FileDateTime = "06/22/2008 04:34";   packInfo.m_NumDownloads = 0;   unsortedFiles.push_back(packInfo);    packInfo.m_PackLine = "Sample Line 2";   packInfo.m_FileDateTime = "12/05/2007 14:54";   packInfo.m_NumDownloads = 1;   unsortedFiles.push_back(packInfo);   for (Iter = unsortedFiles.begin(); Iter != unsortedFiles.end(); Iter++ )  {     cout &lt;&lt; " " &lt;&lt; *Iter; // !!! THIS IS WHERE I GET STUMPED     // How do I output values of the object members?   } }  // end main Why do neural networks need so many training examples to perform? A human child at age 2 needs around 5 instances of a car to be able to identify it with reasonable accuracy regardless of color, make, etc. When my son was 2, he was able to identify trams and trains, even though he had seen just a few. Since he was usually confusing one with each other, apparently his neural network was not trained enough, but still.  What is it that artificial neural networks are missing that prevent them from being able to learn way quicker? Is transfer learning an answer? How to set the chapter style in report class? I want to set chapters to look like 'bigger' sections.  Now in the report class I have a style like:     Chapter 1      Introduction      1.1. Section   What I want to achieve is:        Introduction         1.1. Section   I don't want to change the document class. Proving that the unities of a ring form a group under multiplication When the external resistor increases in temperature, why is the calculated value for internal resistance higher? Say we had a circuit with a cell (with internal resistance)and an external resistor of $10 \Omega$ as shown:  The $10\Omega$ resistor then increases in temperature, leading to an increase in resistance in this resistor. My thinking was that since $10 \Omega$ resistor now has a value higher than $10\Omega$, more voltage drops across this resistor. Since your emf is constant, less voltage must drop across the internal resistor. Less voltage drop means less resistance. Where is the flaw in my logic? Encopresis, I'm at my wits end? Does anybody have suggestions? Creating polygons from points in Mapinfo Opening a context menu (with the Menu key) Bonferroni adjustment in SPSS - what does it do? I'm probably being a bit simplistic here, but from what I understand the Bonferroni post hoc test is simply when we adjust the alpha to account for inflated error when several post hoc tests are conducted. You divide the alpha by number of tests. So what exactly does SPSS do when we click the button for Bonferroni?   Shouldn't the dividing of alpha be done by us in interpreting the result, e.g. if we do 10 post hoc tests our alpha criterion should be .005 so if the p value is .012 then it is not significant, but SPSS hasn't done anything there, we have just changed our interpretation. So what exactly is it adjusting? How to do this manually, not installing any tools? I'm well aware of the combinatorial variant of the proof, i.e. noting that each formula is a different representation for the number of subsets of a set of $n$ elements. I'm curious if there's a series of algebraic manipulations that can lead from $\sum\limits_{i=0}^n \binom{n}{i}$ to $2^n$. If someone could help me with the proposed change of variables, it would be greatly appreciated. Consider Euler's equation:  $$z^2w'' + \alpha zw' + \beta w = 0$$  where $w$ is a function of $z$ and $\alpha, \beta$ are constants. How would the change of variables $t =\ln(z)$ transform this equation? I am looking at some code and it has this statement:    ~ConnectionManager() {     Dispose(false); }   The class implements the IDisposable interface, but I do not know if that is part of that the tilde(~) is used for.