Call Class by String c#
Working with objects created with Activator.CreateInstance
Understanding QGIS buffer tool units I  have had no luck getting the buffer tool to accept anything but degrees as units of measure.  I have found lots of stuff saying the layer needs to be reprojected and saved but it hasn't worked at all for me.   Is there a way I could create a buffer without using ftools or at least force the units to meters somehow?  As a workaround I converted meters to degrees (lat) and used that but the final product needs to be as close to reality as possible.  Things I've tried:   setting every unit option I could find to meters (where possible). setting everything to NAD83/Maryland (data is for Washington, DC) and saving it as such (as layers in ESRI shape files). reimporting the reprojected layers setting relevant layers to Google Mercator   The was tried followed by creating a buffer. Many were tried in combination. QGIS 1.7.3 Slackware64 current (qgis from SBo-13.37 repo, tried on multilib and plain 64it with same results) evaluate $\int_{0}^{\infty}\cos(t) t^{z-1}dt=\Gamma(z)\cos(\frac{\pi z}{2})$ How is my laptop ram running in dual channel? Which badges do not cause a notification for experienced users? \ifmmode doesn't seem to work correctly inside an array environment I’m struggling with getting \ifmmode to work correctly when used inside an array environment which is inside a displaymath environment.  Here is a minimal example:  \documentclass{article}  \newcommand{\signal}[1]{%   \ifmmode     1#1   \else     2$#1$   \fi }  \begin{document} \begin{displaymath}   \begin{array}{cc}     \signal{a} \signal{b} &amp; \signal{c} \signal{d} \\   \end{array} \end{displaymath} \end{document}   This example generates the following output:        Why doesn’t all invokations of \signal detect math-mode? I am simply adding user in 'Monitored Users' in Debug Logs. But User is not getting added. I would like to know how many switch can be stacked with fiber channel to get a best transfer rate between computers.  I have 200 computers connected to 12 3Com switches. All switches have two fiber ports.  Is the best way to have fiber backbone switch and connect fiber channel from every switch to the backbone? Or connect switch 1 to switch 2 to switch 3 to ... switch 12 to switch 1 again?  Thanks! $100$-th derivative of the function $f(x)=e^{x}\cos(x)$ I've got this task I'm not able to solve. So i need to find the 100-th derivative of $$f(x)=e^{x}\cos(x)$$ where $x=\pi$.  I've tried using Leibniz's formula but it got me nowhere, induction doesn't seem to help either, so if you could just give me a hint, I'd be very grateful.  Many thanks! Uncommitted work pending in unit test with trigger and queueable callout I have an after insert trigger that invokes queueable Apex which makes a callout.  The trigger and callout work fine in the UI and I don't get any errors in normal operation.  However, my unit test keeps failing with the "uncommitted work pending" error despite all my attempts to separate the callout.  I've used a testVisible variable to disable the callout from the trigger so that I can invoke the queueable job explicitly in a startTest/stopTest block after the DML that fires the trigger.  I've pored over the callout class to make sure it's not doing any DML beforehand.  Anyway, if it was doing DML, I should get the uncommitted work pending errors in the UI, right?  I've tried API version 37 and version 41 but the unit test still fails.   I've had a case open with Salesforce premier support for 6 weeks now but haven't made any progress.  Any suggestions?  The unit test:  @isTest static void testCallout() {     // Disable the callout while setting up data.     CCx_EHR_CMCT_Services.isQueueSendEnabled = false;      // Set up the data and execute the DML.     / ...     insert act;      // Set up the http mock     // ...      // Now enable and execute the callout     Test.startTest();     CCx_EHR_CMCT_Services.isQueueSendEnabled = true;     Test.setMock(HttpCalloutMock.class, mock);     System.enqueueJob(new QueueSendToRedox(new List&lt;ActivityHL__c&gt;{act}, desk)));     Test.stopTest();  }   Trigger:  trigger HL_ActivityHL_c on ActivityHL__c (before insert, before update, after insert) {     if (Trigger.isAfter) {         if (Trigger.isInsert) {             CCx_ClientDataDomain.sendEHRClinicalComm(Trigger.new);         }     } }   Trigger handler class:  public without sharing class CCx_ClientDataDomain {     public static void sendEHRClinicalComm(List&lt;ActivityHL__c&gt; triggerNew) {     // do some processing here.     // ...     // then queue the callout job.     System.enqueueJob(new CCx_EHR_CMCT_Services.QueueSendToRedox(             deskActivities.get((Id) desk.getDeskId()), desk));     } }   Queueable job class with callout method:  public with sharing class CCx_EHR_CMCT_Services {     // isQueueSendEnabled is an attempted workaround for unit tests     @testVisible     private static Boolean isQueueSendEnabled = true;      public class QueueSendToRedox implements Queueable, Database.AllowsCallouts {         private List&lt;ActivityHL__c&gt; activities;         private CCx_DeskHierarchySelector.Desk desk;         private Boolean isEnabled;          public QueueSendToRedox(List&lt;ActivityHL__c&gt; activities, CCx_DeskHierarchySelector.Desk desk) {             this.activities = activities;             this.desk = desk;             this.isEnabled = isQueueSendEnabled;         }          public void execute (QueueableContext context) {             if(this.isEnabled) sendClinicalCommToRedox(activities, desk);         }     }      public static void sendClinicalCommToRedox(List&lt;ActivityHL__c&gt; activities, CCx_DeskHierarchySelector.Desk desk) {         // Set up data for the callout.  No DML actions are executed before the callout.         HttpRequest req = buildRequest();         // ...          // Callout         Http http = new Http();         HttpResponse resp = http.send(req);     } } I stumbled upon a question given like:  Let $m$ and $n$ be two integers such that $m \geq n \geq 1$.   Count the number of functions $$f: \{1, 2, · · · , n\} \to \{1, 2, · · · , m\}$$ of the following two types:  (a) strictly increasing; i.e., whenever $x &lt; y, f(x) &lt; f(y)$, and  (b) non-decreasing; i.e., whenever $x &lt; y, f(x) \leq f(y)$.  I tried in the following way.  For (a). We can say $f(n)&gt;f(n-1)$ AND $f(n)&gt;f(n-2) \ldots f(n)&gt;f(1)$ (total $n-1$ elements)  Similarly for $f(n-1)&gt;f(n-2), f(n-1)&gt;f(n-3) \ldots f(n-1)&gt;f(1)$ (total $n-2$ elements)...  and $f(2)&gt;1$  Like this $$(n-1) + (n-2) + \ldots + (1) = \frac{n(n-1)}{2}$$  Is this correct?  For (b). Since there's equality, it will be $$n + (n-1) + ... (1) = \frac{n(n+1)}{2}$$  Is my approach correct? Any help is appreciated. Thanks in advance. Hi I would like to know whether the trace of the inverse of a symmetric positive definite matrix $\mathrm{trace}(S^{-1})$ is convex.  Actually I know that the trace of a symmetric positive definite matrix $S\in M_{m,m}$ is convex since we can find $B\in M_{n,m}$ such that $S=B^T\times B$ then we can write the trace as the sum of scalar quadratic forms, i.e. $\mathrm{trace}(S)=\mathrm{trace}(B^T\times B)=\sum_{j=1}^mb_j^T\times b_j$ where $b_j$ is the $j^{th}$ column of $B$.  for instance if we have  $trace([\begin{array}{cc} 1 &amp; 2  \\ 3 &amp; 4  \\ \end{array}] \times [\begin{array}{cc} 1 &amp; 3  \\ 2 &amp; 4  \\ \end{array}])= [\begin{array}{cc} 1 &amp; 2  \\ \end{array}]\times [\begin{array}{c} 1   \\ 2   \\ \end{array}]+ [\begin{array}{cc} 3 &amp; 4  \\ \end{array}]\times [\begin{array}{c} 3   \\ 4   \\ \end{array}]=30$  And so I wonder if $\mathrm{trace}(S^{-1})$ is convex too.. Atomic clocks were used in Hafele and Keatings experiment which supposedly helped to prove time dilation.    How can we be sure other forces didn't act upon the clocks as a result of their being at different speeds and elevations? Perhaps the elapsed time may have been the same for all and only appeared different as a result of the clock's atoms behaving differently in different environments.  How might the presence of dark matter (presumably all over the place) impacted the clocks if say the dark matter is stationary relative to the earth's rotation?  What experiments have been done to test the constancy of clocks at different speeds and elevations? Using Virtual Box, how can I install an OS to a secondary, physical disk, and boot it in both (at separate times) Virtual Box, and as a typical secondary OS install? Scenario: I have a custom button on a standard layout, which will call an apex class to do some validation on a record. If not validated, it needs to throw out some errors on that page. What are the best UX options to achieve this?  I am not too sure how to achieve this. Within a trigger, you can use the addError method to add the custom errors.  Can my Apex class reference the fields of a standard object? The ideal approach would be to do the following:  Contact.Email.addError('Please enter the right format here');   How can I achieve this via an apex class that the custom button will call?  What I have thought: Having a VF Page popup on the screen so that user can see all the errors, but that's not the best approach as UX is a big deal for this application  Thanks. How do you prove that $e=\sum_{n=0}^{\infty}\frac{1}{n!}$? Here I am assuming $e:=\lim_{n\to\infty}(1+\frac{1}{n})^n$. Do you have any good PDF file or booklet available online on this? I do not like how my analysis text handles this... GBM vs XGBOOST? Key differences? I am trying to understand the key differences between GBM and XGBOOST. I tried to google it, but could not find any good answers explaining the differences between the two algorithms and why xgboost almost always performs better than GBM. What makes XGBOOST so fast? Disable browser 'Save Password' functionality One of the joys of working for a government healthcare agency is having to deal with all of the paranoia around dealing with PHI (Protected Health Information). Don't get me wrong, I'm all for doing everything possible to protect people's personal information (health, financial, surfing habits, etc.), but sometimes people get a little too jumpy.  Case in point: One of our state customers recently found out that the browser provides the handy feature to save your password. We all know that it has been there for a while and is completely optional and is up to the end user to decide whether or not it is a smart decision to use or not. However, there is a bit of an uproar at the moment and we are being demanded to find a way to disable that functionality for our site.  Question: Is there a way for a site to tell the browser not to offer to remember passwords? I've been around web development a long time but don't know that I have come across that before.  Any help is appreciated. Deleting comments and review actions cause layout to be broken, AJAX response contains full page How can anything ever fall into a black hole as seen from an outside observer? The event horizon of a black hole is where gravity is such that not even light can escape. This is also the point I understand that according to Einstein time dilation will be infinite for a far-away-observer.  If this is the case how can anything ever fall into a black hole.  In my thought experiment I am in a spaceship with a powerful telescope that can detect light at a wide range of wavelengths.  I have it focused on the black hole and watch as a large rock approaches the event horizon.  Am I correct in saying that from my far-away-position the rock would freeze outside the event horizon and would never pass it? If this is the case how can a black hole ever consume any material, let alone grow to millions of solar masses.  If I was able to train the telescope onto the black hole for millions of years would I still see the rock at the edge of the event horizon?  I am getting ready for the response of the object would slowly fade.  Why would it slowly fade and if it would how long would this fading take?  If it is going to red shift at some point would the red shifting not slow down to a standstill? This question has been bugging me for years!  OK - just an edit based on responses so far.  Again, please keep thinking from an observers point of view.  If observers see objects slowly fade and slowly disappear as they approach the event horizon would that mean that over time the event horizon would be "lumpy" with objects invisible, but not passed through?  We should be able to detect the "lumpiness" should we not through? Is it possible to somehow mark a System.Array as immutable.  When put behind a public-get/private-set they can't be added to, since it requires re-allocation and re-assignment, but a consumer can still set any subscript they wish:  public class Immy {     public string[] { get; private set; } }   I thought the readonly keyword might do the trick, but no such luck.