Since todays morning, I got an exception, if I like to login to any stackexchange site using openid.stackexchange.com with Firefox. (It works with Chrome ...)  I can login to openid.stackexchange.com:    But authorizing to some site fails with the following exception:  Unable to log in with your OpenID provider:     The openid.return_to parameter   ()   does not match the actual URL   ()   the request was made with.
I can't seem to log in with my Stack Exchange OpenID. When I try, I get the error message:     Unable to log in with your OpenID provider:      The openid.return_to parameter (.) does not match the actual URL (.) the request was made with.   It works if I disable the HTTPS-Everywhere plugin in Firefox, but if I then re-enable the plugin and go to a site on which I am not logged in (in which case login is normally nearly seamless), it fails again with the same error message, or at least something very similar.  I'm not aware of having done anything that might have caused this, although I will admit I don't recall seeing https:// in the address bar on Stack Exchange before (I do now, and that's a good thing IMO!). I was using the site  and it worked fine then, but not now...
So lets say I have this interface:  public interface IBox {    public void setSize(int size);    public int getSize();    public int getArea();   //...and so on }   And I have a class that implements it:  public class Rectangle implements IBox {    private int size;    //Methods here }   If I wanted to use the interface IBox, i can't actually create an instance of it, in the way:  public static void main(String args[]) {     Ibox myBox=new Ibox(); }   right? So I'd actually have to do this:  public static void main(String args[]) {     Rectangle myBox=new Rectangle(); }   If that's true, then the only purpose of interfaces is to make sure that the class which implements an interface has got the correct methods in it as described by an interface? Or is there any other use of interfaces? What is a complete list of the usual assumptions for linear regression? Solve simple trig equation Hi I am working on a website for a student organization of my college.  In order to prevent spams, I have been looking for ways to limit account applicants only with email addresses from the college but haven't figure out how What do two question marks together mean in C#? What is a reliable method to locate floating islands in Terraria? Toolbar options are not displaying in Edit Profile - About me section Is this sentence acceptable?     You’re welcome, have a nice day ahead. How do you test non-live sites before switching DNS? I have a few websites that I need to move to a new server - how would I test that they work before switching DNS? What URL would I navigate to? The bijection between homogeneous prime ideals of $S_f$ and prime ideals of $(S_f)_0$ In our application, we receive text files (.txt, .csv, etc.) from diverse sources. When reading, these files sometimes contain garbage, because the files where created in a different/unknown codepage.  Is there a way to (automatically) detect the codepage of a text file?   The detectEncodingFromByteOrderMarks, on the StreamReader constructor, works for UTF8  and other unicode marked files, but I'm looking for a way to detect code pages, like ibm850, windows1252.     Thanks for your answers, this is what I've done.  The files we receive are from end-users, they do not have a clue about codepages. The receivers are also end-users, by now this is what they know about codepages: Codepages exist, and are annoying.  Solution:    Open the received file in Notepad, look at a garbled piece of text. If somebody is called François or something, with your human intelligence you can guess this. I've created a small app that the user can use to open the file with, and enter a text that user knows it will appear in the file, when the correct codepage is used.  Loop through all codepages, and display the ones that give a solution with the user provided text.  If more as one codepage pops up, ask the user to specify more text. The only 1-manifolds are $\mathbb R$ and $S^1$ I recall having heard somewhere that the only 1-manifolds (second countable, Hausdorff, connected spaces locally homeomorphic to $\mathbb R$) are $\mathbb R$ and $S^1$. Is this true? If so, is there a reasonably elementary proof? Draw somewhat random function I am trying to reconstruct this image here    I am not very happy with the code, as it uses hacking and adding white boxes and alike. My problem is now how do I draw the somewhat arbitary function in the figure? I tried to do a polynomial fit, but that did not work. I got dimensions to large, would a spline solution work better?    \documentclass{standalone}     \usepackage{tikz}     \usetikzlibrary{patterns}     \usepackage{pgfplots}     \pgfplotsset{compat=1.6}     \begin{document}     \begin{tikzpicture}      \begin{axis}[         xmin=-0.1,xmax=5,         xlabel={z},         ymin=0,ymax=4.5,     xtick={2.5,4},     xticklabels={$v_1$,$v_2$},     ytick={2.5,3.5},     yticklabels={$u_1$,$u_2$},     xlabel={$u$},       ylabel={$v$},     axis lines=middle]  \draw [fill=gray!40!white,thick,dashed] (axis cs:0,0) rectangle (axis cs:4,3.5); \draw [color=black,fill=white,thick,dashed] (axis cs:0,0) rectangle (axis cs:2.5,2); \draw [fill=black] (axis cs:0,0) rectangle (axis cs:0.01,4.45); \addplot+[black,thick,domain=0:5,no marks] {0}; % \node at (axis cs:2.5,0)    [anchor=south west] {$A$}; \node at (axis cs:4,0)      [anchor=south west] {$A'$}; \node at (axis cs:2.8,2.2)  [anchor=north]      {$B$}; \node at (axis cs:4.2,4)   [anchor=north]       {$B'$}; \node at (axis cs:0.25,2.5) [anchor=north]      {$C$}; \node at (axis cs:0.25,4)   [anchor=north]      {$C'$}; \node at (axis cs:0,0)     [anchor=south west]  {$O$}; % \end{axis} \end{tikzpicture} \end{document} Why is the sum of two random variables a convolution? For long time I did not understand why the "sum" of two random variables is , whereas a mixture density function sum of $f(x)$ and $g(x)$ is $p\,f(x)+(1-p)g(x)$; the arithmetic sum and not their convolution. The exact phrase "the sum of two random variables" appears in google 146,000 times, and is elliptical as follows. If one considers an RV to yield a single value, then that single value can be added to another RV single value, which has nothing to do with convolution, at least not directly, all that is is a sum of two numbers. An RV outcome in statistics is however a collection of values and thus a more exact phrase would be something like "the set of coordinated sums of pairs of associated individual values from two RV's is their discrete convolution"...and can be approximated by the convolution of the density functions corresponding to those RV's. Even simpler language: 2 RV's of $n$-samples are in effect two n-dimensional vectors that add as their vector sum.           Please show the details of how the sum of two random variables are a convolution and a sum. I have QGIS 1.8.0 installed via OSGeo Installer and work on win 7. All I need is to upload the shapefile to the database via this plugin. Unfortunately I am receiving an error:  Something's wrong: ["'shp2pgsql' is not recognized as an internal or external command,\n", 'operable program or batch file.\n']   How to install and configure shp2pgsql to make this plugin work fine? I'm having trouble understanding the simple voltage regulator that can be built using a zener diode (from section 2.04 in the Art of Electronics).  I know that it would be better to use amplifiers, et cetera, but I'm just trying to understand how this circuit works.      I don't really understand how the circuit works, but I am guessing that when a load is applied to the output, it drains current from the source (Vin) and thus causes the voltage to drop?  How does the zener diode help to maintain the voltage and thus make this circuit act as a regulator? Usage of brackets/parentheses When and how do we use the different kinds of brackets/parentheses&nbsp;— (){}[]&nbsp;— while writing English (not code)? Is there PvP in Diablo 3? How does it work? Age from Date of Birth using JQuery I need to calculate if someone is over 18 from their date of birth using JQuery.  var curr = new Date(); curr.setFullYear(curr.getFullYear() - 18);  var dob = Date.parse($(this).text());  if((curr-dob)&lt;0) {     $(this).text("Under 18"); } else {     $(this).text(" Over 18"); }   There must be some easier functions to use to compare dates rather than using the setFullYear and getFullYear methods.  Note: My actual reason for wanting to find a new method is length of the code. I have to fit this code into a database field that is limited to 250 chars. Changing the database is not something that can happen quickly or easily. Why gpedit and the corresponding registry entries are not synchronized?