I am a new user of QGIS, and I just downloaded the version 2.4 on Windows 7/32 bits. And I seem to encounter several problems:   I cannot install OpenLayers plugin In the "Plugins" tab under "Manage and install plugins" I have only 3 windows "All", "Installed" and "Settings" and it is missing "Not installed"...and here either I open the "all" or "installed" window I have the same number of plugins, that is 23...and I cannot make any modifications like "upgrade" or "uninstall" etc...   Dos any one have an idea what is happening with my QGIS version? Or if I did something wrong when installing...I know that I just followed the easy installation for new users...
I have been trying to teach myself QGIS by using this forum and others to help. Most of my questions can be answered by downloading plugins that are available through 3rd party repositories but for some reason I am not able to connect with these. Anyone have any ideas why this is the case?
I know that RAM disks are fast, faster than any disk, but they lose their contents on a shutdown of the operating system. The capacity is limited to the RAM. Is there a useful implementation on a new 64-bit Windows 2008 server? TypeError: Element-wise multiplication: not supported between 'Matrix' and 'Vector' What does general relativity say about the relative velocities of objects that are far away from one another? What does general relativity say about the relative velocities of objects that are far away from one another? In particular:--  Can distant galaxies be moving away from us at speeds faster than $c$? Can cosmological redshifts be analyzed as Doppler shifts? Can I apply a Lorentz transformation in general relativity? Process Builder - Breaking Production Deployments? I have a Process Builder flow set up and I am running some tests around the InvocableMethod Apex code. The tests pass fine in my staging and production environments. Yet, when I try to deploy to production, I get a strange error.  CANNOT_EXECUTE_FLOW_TRIGGER, The record couldn’t be saved because it failed to trigger a flow.  Thankfully I received a somewhat more informative error email.  UPSERT FAILED ---  ERRORS :  (CANNOT_EXECUTE_FLOW_TRIGGER) The record couldn’t be saved because it failed to trigger a flow. common.exception.AssertionException: ORA-20070: Cannot read from apex_class and apex_trigger while running tests ---  for SFDC record with ID : null,  Unfortunately, the deployment has nothing to do with the flow and it is unclear why it is failing. What is the root cause of this error and how can I fix it? EDIT: I found out this is a . The other claimed workaround is to deploy via the Metadata API. UPDATE: Because I was subscribed to the Known Issue, I received the following confirmation this issue is resolved.  We are pleased to notify you that the following Known Issue has been resolved: Executing an InvocableMethod during an apex test run from a change set can cause Errors. Thank you for being patient while we worked to address this issue. Please feel free to reach out to Customer Support if you have further questions. Sincerely, Salesforce Success Team I was presented with the following problem:      Prove that there exist solutions to $x^2+y^2=z^n$ for all $n$, with $x,y,z, n \in \mathbb{N}$   I showed that by taking any Pythagorean triple $x^2+y^2=z^2$ and multiplying by $z^{2(n-1)}$ we get $(z^{n-1}x)^2+(z^{n-1}y)^2=(z^2)^n$, which allows me to generate solutions easily for any value of $n$. I managed to find several similar questions on this site, such as  concerning the specific case $n=3$. I notice that all of these questions take a similar approach and start with a Pythagorean triple and use it to generate general solutions.  Is there a way to prove the statement (or better yet provide solutions to the equation) without first relying on Pythagoras? How to connect to remote X-Server (logged in via ssh) When I'm logged on to another host (e.g via ssh), how do I connect to the XServer of that machine (same user is logged in and is running a desktop (gnome))?  You may ask way I wish to do that: There are commands that don't open an X-Window, e.g. xinput, xhost, etc.. and there are situations where you want to run them from remote. Inversion in "only [adverb] have they" How do I clone a subdirectory only of a Git repository? I have my Git repository which, at the root, has two sub directories:  /finisht /static   When this was in , /finisht was checked out in one place, while /static was checked out elsewhere, like so:  svn co svn+ssh://admin@domain.com/home/admin/repos/finisht/static static   Is there a way to do this with Git? An unclear sentence in the book "Griffiths, Harris-Principles of algebraic geometry" Let $X$ be a complex manifold and consider a holomorphic vector bundle $\pi:E\to X$ of rank $r$. By the usual correspondence between vector bundles and locally free sheaves, we consider $E$ as a sheaf by abuse of notation. We denote with $\mathscr A_X^{p,q}$ the sheaf of $C^\infty$ $(p,q)$-differential forms on $X$ and we define: $$A^{p,q}(E):=\Gamma(X,\mathscr A^{p,q}\otimes_{\mathscr O_X} E)$$ $$A^k(E):=\bigoplus_{p+q=k}A^{p,q}(E)$$  Now suppose that $\nabla:A^\bullet(E)\to A^\bullet(E)$ is a linear connection on $E$, then the curvature operator is defined as: $$\nabla^2:A^0(E)\to A^2(E)$$ where $\nabla^2$ is the composition of the maps $\nabla: A^0(E)\to A^2(E)$   and $\nabla: A^1(E)\to A^2(E)$. One can show that $\nabla^2$ is $C^\infty(X)$-linear.    I don't understand the following sentence from the Griffiths-Harris book at page 75 (I rephrase it by using my notation):     Since $\nabla^2$ is $C^\infty(X)$-linear, then it is induced by a bundle map $E\to\bigwedge^2T^*X\otimes E$, or in other words, $\nabla^2$ corresponds to a global section $\Theta$ of the bundle $\bigwedge^2T^*X\otimes\operatorname{Hom}(E,E)$.   I absolutely don't understand how I can see the operator $\nabla^2$ as the section $\Theta$. Why does the area of a bar in a histogram represent the frequency of that particular class In a bar-graph, the height of the bars represent the frequency of a particular category but it is counter-intuitive that in a histogram, instead of the height of the bar(which represents the frequency density), the area of the bar represents the frequency of the particular class. Why is this so? WCF - Faults / Exceptions versus Messages We're currently having a debate whether it's better to throw faults over a WCF channel, versus passing a message indicating the status or the response from a service.  Faults come with built-in support from WCF where by you can use the built-in error handlers and react accordingly. This, however, carries overhead as throwing exceptions in .NET can be quite costly.  Messages can contain the necessary information to determine what happened with your service call without the overhead of throwing an exception. It does however need several lines of repetitive code to analyze the message and determine actions following its contents.  We took a stab at creating a generic message object we could utilize in our services, and this is what we came up with:  public class ReturnItemDTO&lt;T&gt; {     [DataMember]     public bool Success { get; set; }      [DataMember]     public string ErrorMessage { get; set; }      [DataMember]     public T Item { get; set; } }   If all my service calls return this item, I can consistently check the "Success" property to determine if all went well. I then have an error message string in the event indicating something went wrong, and a generic item containing a Dto if needed.  The exception information will have to be logged away to a central logging service and not passed back from the service.  Thoughts? Comments? Ideas? Suggestions?  Some further clarification on my question  An issue I'm having with fault contracts is communicating business rules.  Like, if someone logs in, and their account is locked, how do I communicate that? Their login obviously fails, but it fails due to the reason "Account Locked".  So do I:  A) use a boolean, throw Fault with message account locked  B) return AuthenticatedDTO with relevant information Approximating $\pi$ with least digits Do you a digit efficient way to approximate $\pi$? I mean representing many digits of $\pi$ using only a few numeric digits and some sort of equation. Maybe mathematical operations also count as penalty.  For example the well known $\frac{355}{113}$ is an approximation, but it gives only 7 correct digits by using 6 digits (113355) in the approximation itself. Can you make a better digit ratio?  EDIT: to clarify the "game" let's assume that each mathematical operation (+, sqrt, power, ...) also counts as one digit. Otherwise one could of course make artifical infinitely nested structures of operations only. And preferably let's stick to basic arithmetics and powers/roots only.  EDIT: true. logarithm of imaginary numbers provides an easy way. let's not use complex numbers since that's what I had in mind. something you can present to non-mathematicians :) I've tried to find any solution or proof for $$\langle x| x' \rangle=\delta(x-x'),$$ but I only came to this post:   So I got the information, that the vector $|x\rangle$ form a dirac-normalized basis for the Hilbert Space.   I know that the dirac-delta distribution is defined like this: $$\delta(x-x') = \begin{cases} 0 &amp;\mbox{if } x\neq x' \\ \infty &amp; \mbox{if } x=x' \end{cases},$$ this means that my x' is a point on my x axis where I have my infinite high peak. And also $$\int_{-\infty}^{\infty}dx\cdot \delta(x-x')=1.$$  But how actually correlate this with the scalar product of vectors x, x' in the Hilbert Space that form a so-called 'diracl-normailzed" basis of it?  Can you give me some tips on this please? Or maybe you actually know a link, where this is explained. Converting Degree Minutes to decimal degrees using Excel formula? I have location points collected from a garmin device stored in an excel sheet in Degree Minutes format --- W00208.172,N1046.977.  I am looking for an Excel formula to convert either to Decimal Degrees or Degrees Minutes seconds Format ? Show that a ring is commutative if it has the property that ab = ca implies b = c when $a\neq 0$.   This is my proof to show that a ring is commutative if it has the property that ab = ca implies b = c.  We need to show that if x, y ∈ R then xy = yx. Let a = x, b = yx and c = xy. Then ab = x(yx) = (xy)x = ca. Thus, by the hypothesis, b = c, or xy = yx. Thus, for x, y ∈ R we have xy = yx.   How would I show when $a\neq 0$? "I cannot seem to find it" What's the opposite word for "sin"? I would like to know if there is an opposite word for sin in English.  I mean, how could I say the opposite of     I committed a sin   other than using a negation? Problem about angle in isosceles triangle $ABC$ is an isosceles triangle, $AB=AC$, and $\measuredangle A=20^{\circ}$. For point $M$ on $AB$ and $N$ on $AC$, we have $AM=NC=BC$. Compute the  $\measuredangle BMN$.  In a similar problem (with only one point on one side) the key step was to construct an equilateral triangle on the other side. I tried using that in this problem too, but I didn't manage to solve it. Given a DateTime object, how do I get an ISO 8601 date in string format? How can I repair a ceiling fan that hums, but doesn't turn?