I installed the newest version of cinnamon on my ubuntu 13.04 only to see how good it looks, hoping that I would still be able to use Unity if I didn't like it. It turns out it was a bad idea because cinnamon broke not only unity (to the point of complete uselessness) but also crucial system functions like the software center and bug reporting.  I tried to reinstall unity using terminal (I found a tutorial but I can't recall exactly what commands were there, 'reinstall ubuntu-desktop' or something like that) and purge cinnamon (with another tutorial) and now unity runs pretty much ok, but software center doesn't open and bug reporting causes a big crash (restart needed). Furthermore I can't access the 'appearance' option, it just doesn't start.  Is there way of restoring things as they were before cinnamon? Or I messed to much and have to reinstall ubuntu?
Since upgrading to 13.10, I can't log in to unity desktop. Light dm works correctly, but attempting to log in tries to start the session then drops back to light. I've already dropped to terminal (ctrl+alt+f2) and done this:  sudo apt-get update  sudo apt-get install --reinstall ubuntu-desktop  sudo apt-get install unity   Logging in as a guest session also fails. Logging in to other window managers works with varying degrees of success.  Note: I have Cinnamon 2.0 installed from PPA.  I'm using a 2 monitor setup.  Also of note is that the session prior to my upgrade to 13.10 the background of unity failed to display at all, instead showing what was there in the screen buffer from the previous frame. The entire OS worked correctly otherwise though, so I just ignored it for the session. No other upgrades or even updates were done prior to this occurring.  My upgrade path to 13.10 was basically this: Install 13.04 alongside Windows 7, use ubuntu as a glorified web browser for a while, get updates (in preparation for 13.10), install 13.10.  I also used Unity Tweak Tool to change some aspects of unity, particularly auto-hide.  Any help or ideas would be appreciated, as I'm typing this on my phone :(
How are Python's Built In Dictionaries Implemented? Does anyone know how the built in dictionary type for python is implemented?  My understanding is that it is some sort of hash table, but I haven't been able to find any sort of definitive answer. How do you convert a matrix to a cell array of equivalent size? Schengen visa refusal on threat to public policy, security, health I applied for German Schengen visa as a medical escort to my relative in a different country from  where I reside, but my visa application was refused and the refusal letter  was written in German as the following:        Ein oder mehrere Mitgliedstaaten sind der Auffassung, dass Sie eine Gefahr für die öffentliche Ordnung, die innere Sicherheit, die   öffentliche Gesundheit gemäß Artikel 2 Absatz 19 der Verordnung (EG)   Nr 562/2006 (Schengener Grenzkodex) oder die internationalen   Beziehungen eines oder mehrerer Mitgliedstaaten darstellen.      I was in Germany for nearly a year with my relative during his treatment; I extended my stay there 3 times; and I returned back home two months ago in order to renew my passport. I applied again using the same documents that I used for my extension in Germany.    First, can anyone tell me what the refusal means? Next, is there any possibility that there is a mistake in the assessment?    Note: In English this reason is...     One or more member state(s) consider you to be a threat to public   policy, internal security, public health as defined in Article 2(19)   of Regulation (EC) No 562/2006 (Schengen Borders Code) or the   international relations of one or more of the member states). Do I need a transit vsa in Kuwait; what about checked baggage? Android SQLite database: slow insertion Proving that, $|f'(x)-f'(y)|\le k|x-y| \implies (f'(x))^2< 2 kf(x) $ Let $f:\Bbb R\to (0,\infty)$ be a differentiable function such that for some constant $k$ we have, $$|f'(x)-f'(y)|\le k|x-y|$$   for all $x,y \in\Bbb R.$ Then prove that, $$(f'(x))^2&lt;2 kf(x).$$   Due to lack of arguments I could not proof this inequality. But rather I proved that is true for the particular function,   $$f(x) =\cos^2(x)+1\implies f'(x) = -\sin(2x).$$ And we readily have,$$|\sin(2x)-\sin(2y)| = \left|\int_{2x}^{2y}\cos t dt\right|\le 2|x-y|$$ as well   $$(f'(x))^2 = 4 \sin^2 x\cos^2x &lt; 4(\cos^2x +1) = 4f(x).$$  It is also true for the function $x\mapsto \sin^2x +1.$   From these example I don't see how to prove the general case. Any hint will be welcome. Let $V,W$ be two vector spaces over a field $F$ and let $f:V \to W$ be a linear mapping. I have going over some facts about vector spaces (not necessarily finite dimensional) and I have been trying to apply the rank nullity theorem to derive a simple lemma.  I have not been able to complete the proof and was wondering if I need to use something other then $\ker f + \mathrm{Im}\; f = \dim V$.  How do we show that for ever vector subspace $K \subset W$, $ \dim(f^{-1}(K)) = \dim(K \cap \mathrm{Im}\; f) + \dim( \mathrm{Ker}\; f)$? Will Area 51 be supported in the app? Will  be supported on the Android App in the future? I visit A51 rather frequently and I would like to see it in the App. I would like to install Ubuntu  for almost 120 users. But it's very difficult in using USB and drives.  Any suggestions? What does "sudo apt-get update" do? I am wondering what sudo apt-get update does?  What does it update? I have 4GB RAM. When I open Firefox, IntelliJ IDEA or VS Code and some other application my memory is about used up thus my machine hangs and I can't do anything. I can't even close any applications.    Date and time are shown in the top bar so that I can view it any time without any thing typing.   If I would view memory status in this way without typing anything then I can make a decision whether to open an application or whether this application may put my machine in hanging state or not.    Is it possible in Ubuntu 18.04 LTS? Case-insensitive string comparison in C++ Windows 10 high memory usage (unknown reason) A few days ago I updated my PC to Windows 10. However, after some use my PC started to slow down until it was impossible to use – it was due to high memory usage. After a restart, everything came back to normal (total usage around 25% of 8GB of RAM). However, during a few hours of usage the memory builds up again to 70%, and if not restarted it further goes to 100%, and later on even freezes. Task manager does not help very much as it does not show all the processes (added screenshots below). Also tried RAMMap but it gives an error: "error refreshing database". I tried Googling this question, yet without much success.  I do not know much about PCs, but maybe some of you know this issue, or could help to find out what is using my RAM. If I have the following enum:  public enum ReturnValue{     Success = 0,     FailReason1 = 1,     FailReason2 = 2     //Etc... }   Can I avoid casting when I return, like this:  public static int main(string[] args){     return (int)ReturnValue.Success; }   If not, why isn't an enum value treated as an int by default? We're working on a Log Viewer. The use will have the option to filter by user, severity, etc. In the Sql days I'd add to the query string, but I want to do it with Linq. How can I conditionally add where-clauses? How to get images to planes objects to receive shadow? What is the quantum mechanical explanation of the octet rule? What is the quantum mechanical explanation of the ? In other words, what makes the octet rule be true from a quantum mechanical view? How we explain  what makes some atoms don't follow the octet rule using QM? Expanding code in etoolbox's \ifblank I am trying to use the etoolbox \ifblank (and its cousin \notblank), but I want to expand any macros in its test statement.  For example:  \documentclass{article} \usepackage{etoolbox}  \begin{document}  \newtoggle{longformt} \newcommand{\longform}{\toggletrue{longformt}} \newcommand{\iflong}[2]{\iftoggle{longformt}{#1}{#2}}  \newcommand{\quoteifnotblank}[1]{%     \notblank{#1}{``#1''}{}% }  % Try commenting this line. \longform  This should be completely blank if the form is short: \quoteifnotblank{\iflong{Some long quoted text}{}}  \end{document}   The problem here is that \notblank sees its argument of \iflong{Some long quoted text}{} as a string, not as code to be expanded, so the quotes always appear.  How do I expand arguments before they are passed to \notblank? I want to be able to make callouts to JotForm, but they do not support OAuth and username/password is insufficient for their API. ; for reference, here are the 3 auth options:        Authenticate with Query Parameters   Authenticate with HTTP Headers   Authenticate with Javascript SDK      Basically, they provide an API Key and want me to include an apikey parameter in the header. I don't want to hard code it, I don't want to store it as plain text in custom settings/metadata, and this isn't a managed package. Is there any way to securely store/authenticate from Salesforce, ideally using a Named Credential?  I'd love to be able to just have a Named Credential that is just a securely stored, obscured API Key... How can I check if a program exists from a Bash script?