Interlock.Add() for double
Why is there no overload of Interlocked.Add that accepts Doubles as parameters?
I have written code like below and all works fine, but while submitting the form I get the error below. I am trying to filter the second dropdown based on the first drop down selection.     An illegal choice has been detected. Please contact the site administrator.   How do I overcome that error?       function dynamic_location_dropdown_form_alter(&amp;$form, $form_state, $form_id) {   if($form_id == 'product_node_form') {    $location_options = array();    if(isset($form['field_destination']['und']['#default_value'][0])) {     $destination = $form['field_destination']['und']['#default_value'][0];   }   else {     $destination = 0;   }    $location_options = dynamic_location_dropdown_locations($destination);    $form['field_destination']['und']['#ajax'] = array(     'event' =&gt; 'change',     'wrapper' =&gt; 'squadron-wrapper',     'callback' =&gt; 'dynamic_location_dropdown_ajax_callback',     'method' =&gt; 'replace',   );   $form['field_product_location']['#validated'] = true;   $form['field_product_location']['und']['#prefix'] = '&lt;div id="squadron-wrapper"&gt;';   $form['field_product_location']['und']['#suffix'] = '&lt;/div&gt;';   $form['field_product_location']['und']['#options'] = $location_options;   } }  function dynamic_location_dropdown_ajax_callback($form, $form_state) {   $country_id = $form['field_destination']['und']['#value'];   $form['field_product_location']['#validated'] = true;   $form['field_product_location']['und']['#options'] =  dynamic_location_dropdown_locations($country_id);    return $form['field_product_location']; }  function dynamic_location_dropdown_locations($destination_id) {   $nodes = array();   $nodes[''] = '- None -';   if($destination_id != '') {     $select = db_query("       SELECT node.title AS node_title, node.nid AS nid, node.created AS node_created       FROM {node} node       LEFT JOIN {field_data_field_location_country} field_data_field_location_country        ON node.nid = field_data_field_location_country.entity_id        AND (field_data_field_location_country.entity_type = 'node'        AND field_data_field_location_country.deleted = '0')       WHERE (( (node.status = '1')        AND (node.type IN  ('location'))        AND (field_data_field_location_country.field_location_country_nid = $destination_id)))       ORDER BY node_title ASC     ");     $nodes[''] = '- None -';     foreach ($select as $node) {       $nodes[$node-&gt;nid] = $node-&gt;node_title;     }   }    return $nodes; } How do I unit test (using xUnit) a class that has internal private methods, fields or nested classes? Or a function that is made private by having  (static in C/C++) or is in a private () namespace?  It seems bad to change the access modifier for a method or function just to be able to run a test. Maximal order of an element in a symmetric group If we let $S_n$ denote the symmetric group on $n$ letters, then any element in $S_n$ can be written as the product of disjoint cycles, and for $k$ disjoint cycles, $\sigma_1,\sigma_2,\ldots,\sigma_k$, we have that $|\sigma_1\sigma_2\ldots\sigma_k|=\operatorname{lcm}(\sigma_1,\sigma_2,\ldots,\sigma_k)$.  So to find the maximum order of an element in $S_n$, we need to maximize $\operatorname{lcm}(\sigma_1,\sigma_2,\ldots,\sigma_k)$ given that $\sum_{i=1}^k{|\sigma_i|}=n$. So my question:      How can we determine $|\sigma_1|,|\sigma_2|,\ldots,|\sigma_k|$ such that $\sum_{i=1}^k{|\sigma_i|}=n$ and $\operatorname{lcm}(\sigma_1,\sigma_2,\ldots,\sigma_k)$ is at a maximum?   Example  For $S_{10}$ we have that the maximal order of an element consists of 3 cycles of length 2,3, and 5 (or so I think) resulting in an element order of $\operatorname{lcm}(2,3,5)=30$.  I'm certain that the all of the magnitudes will have to be relatively prime to achieve the greatest lcm, but other than this, I don't know how to proceed. Any thoughts or references? Thanks so much. How do I remove all sub-directories from within a directory? This question is kind of a phase II to the first question I posted at   I have a directory that contains a bunch of sub-directories, .zip files, and other random files not contained within a sub-directory.  I'd like a command line script to remove all sub-directories from within the parent directory, but keep all zip files and loose files that don't belong to any sub-directories. All of the sub-directories have content, so I believe I'd need to force their deletion with the -f command.  So basically, a command that looks inside the parent directory (or the current directory), deletes all folders from within it, but keeps all other content and files that are not a folder or contained within a folder.  I understand that deleting items from the command line requires special care, but I have already taken all necessary precautions to back up remotely. How to get own process pid from the command prompt in Windows I'm trying to find a way to get my own PID from a command prompt (for later use in bat scripts).  So far the only useful way I found was to use getpids.exe from here : , but I'm looking for a command that's "built in" to Windows.  I'm looking for a "bullet proof" way. No assumptions about my process being the only cmd.exe or anything. Stack Overflow in ES, PT, RU, JP have mixed-language descriptions In categorical terms, why is there no canonical isomorphism from a finite dimensional vector space to its dual? I've read in several places that one motivation for category theory was to be able to give precise meaning to statements like, "finite dimensional vector spaces are canonically isomorphic to their double duals; they are isomorphic to their duals as well, but not canonically."  I've finally sat down to work through this, and -  Okay, yes, it is easy to see that the "canonical isomorphism" from $V$ to $V^{**}$ is a functor that has a natural isomorphism (in the sense of category theory) to the identity functor.  Also, I see that there is no way that the functor $V\mapsto V^*$ could have a natural isomorphism to the identity functor, because it is contravariant whereas the identity functor is covariant. My question amounts to:     Is contravariance the whole problem?   To elaborate:   I was initially disappointed by the realization that the definition of natural isomorphism doesn't apply to a pair of functors one of which is covariant and the other contravariant, because I was hoping that the lack of a canonical isomorphism $V\rightarrow V^*$ would feel more like a theorem as opposed to an artifact of the inapplicability of a definition.  Then I tried to create a definition of a natural transformation from a covariant functor $F:\mathscr{A}\rightarrow\mathscr{B}$ to a contravariant functor $G:\mathscr{A}\rightarrow\mathscr{B}$. It seems to me that this definition should be that all objects $A\in\mathscr{A}$ get a morphism $m_A:F(A)\rightarrow G(A)$ such that for all morphisms $f:A\rightarrow A'$ of $\mathscr{A}$, the following diagram (in $\mathscr{B}$) commutes:  $$\require{AMScd}\begin{CD} F(A) @&gt;m_A&gt;&gt; G(A)\\ @VF(f)VV @AAG(f)A\\ F(A') @&gt;&gt;m_{A'}&gt; G(A') \end{CD}$$  This is much more stringent a demand on the $m_A$ than the typical definition of a natural transformation.  Indeed, it is asking that $m_A=G(f)\circ m_{A'}\circ F(f)$, regardless of how $f$ or $A'$ may vary. Taking $\mathscr{A}=\mathscr{B}=\text{f.d.Vec}_k$, $F$ the identity functor and $G$ the dualizing functor, it is clear that this definition can never be satisfied unless $m_V$ is the zero map for all $V\in\text{f.d.Vec}_k$ (because take $f$ to be the zero map). In particular, it cannot be satisfied if $m_V$ is required to be an isomorphism.     Is this the right way to understand (categorically) why there is no natural isomorphism $V\rightarrow V^*$?   As an aside, are there any interesting cases of some kind of analog (the above definition or another) of natural transformations from covariant to contravariant functors?  Note: I have read a number of math.SE answers regarding why $V^*$ is not naturally isomorphic to $V$. None that I have found are addressed to what I'm asking here, which is about how categories make the question and answer precise. ( was closest.) Hence my question here. Was the chip real or fake? I'm talking about the movie  Spoilers ahead.  Walter (Daniel Radcliffe) gave the task or blackmailed the Four Horsemen to steal a chip from a lab which can access any digital device. So they did steal the chip. And when they rescue Dylan Rhodes (Mark Ruffalo) from drowning in the water, Jack Wilder said that the chip is fake.     Jack: Wait something is not right.      Atlas: What's wrong?      Jack: It's fake.   Then they assumed that Walter did not know that the chip is fake. So they came with a plan to bluff. They pretended that they had the real chip. After they got caught by Walter, they gave the fake chip to Walter. Walter checked the chip and declared it as real. The Four Horsemen were surprised.     Walter: I'm sorry to interrupt. But I have to say congratulations and   thank you. It's real.      Lula: What? It's real!!!!!      Atlas: What? Is it real?      Jake: What is he talking about?   What happened? I didn't get it. What did I miss? Was the chip real? Was Walter pretending it to be real? If so, then why? If not, who switched the real chip with the fake one? Who had the real chip before? Switch statement fallthrough in C#? How do I kill the lockscreen after the Windows 10 anniversary update? What is the benefit of breaking up a continuous predictor variable? I'm wondering what the value is in taking a continuous predictor variable and breaking it up (e.g., into quintiles), before using it in a model.   It seems to me that by binning the variable we lose information.   Is this just so we can model non-linear effects?  If we kept the variable continuous and it wasn't really a straight linear relationship would we need to come up with some kind of curve to best fit the data? How do you compare two version Strings in Java? Is there a standard idiom for comparing version numbers?  I can't just use a straight String compareTo because I don't know yet what the maximum number of point releases there will be.  I need to compare the versions and have the following hold true:  1.0 &lt; 1.1 1.0.1 &lt; 1.1 1.9 &lt; 1.10 Possible Duplicate:          I know that I have to find the number of factors of $5$'s, $25$'s, $125$'s etc. in order to do this. But how can you derive such a formula for any number $n$? Difference between I and Me I am quite confused with the usage of I and me, Can anybody tell me what should be used in the following sentence: Your husband doesn't believe that You're older than (I / Me). How do I recover or "undelete" files that I accidentally deleted? I've accidentally deleted some really important files on my machine, and I'm looking to find out how to recover them.  Using the Trash bins "restore" isn't an option, as the files aren't there (mostly likely I wasn't paying attention and permanently deleted them from there).  Is there any way that I can un-delete these files? Good refactoring support for C++ The Visual Studio refactoring support  for C# is quite good nowadays (though not half as good as some Java IDE's I've seen already) but I'm really missing C++ support.  I have seen  and am currently trying it out, but maybe one of you guys know a better tool or plugin?  I've been working with  now for a week or two and got totally addicted. Thanks for the tip, I'll try to convince my boss to get me a license at work too.  I've been bughunting for a few days since Visual Assist X kept messing up my Visual Studio after a few specific refactorings, It took me (and customer support) a week to hunt down but let's say for now that Visual Assist X is not a good combination with . Is FFmpeg missing from the official repositories in 14.04? I tried to install ffmpeg in trusty/Ubuntu 14.04 and got the following message:  $sudo apt-get install ffmpeg  Reading package lists... Done Building dependency tree        Reading state information... Done Package ffmpeg is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source  E: Package 'ffmpeg' has no installation candidate   Why isn't the package available? Can I submit an edit for approval after earning 2k reputation? I have now enough reputation points on Stack Overflow to edit every post directly. But sometimes (especially if this is about a field where I'm not savvy, or when I try to edit a question title without having understood the question itself) I might be not totally sure about whether my edit really is an improvement.  For now, I have these options:   Do the edit anyway, hope that someone else will catch it if it is wrong Don't do the edit, and hope that someone else will see this post and edit it in the right way Let a comment and hope that someone will see it (either after editing or instead of it). Flag the post for moderator attention (but will the moderators know it better?) Search the right chat room to find someone who knows more about the topic.   All these are not really optimal, I think.  I would like to have a check box     [_] Submit this edit for approval   which, when checked, would submit the edit into the usual edit approval queue. Then I would get at least one or two other pairs of eyes looking over my edit, and maybe even improving it.  (I don't really care about the +2 reputation for the edit - I think it should be without any reputation difference here.)  There's an  for nearly giving everyone the ability to suggest edits that the post owner can approve, but I'm simply interested in being able to insert them into the general edit queue where anyone can approve them.  Actually, I could do this right now by having a low-reputation sock puppet (or a totally anonymous edit), but I think this is not the intended use for sock puppets, is it? Also, I would like to be able to get feedback for my edit. I have a shape (rounded rectangle) in PowerPoint 2007 of which I would like to increase the vertical size only (to illustrate de-bottlenecking). So, the width will stay the same but the height will grow (both from the top and bottom, so the centre will remain in the same location).  Custom Animation -> Emphasis only appears to change the whole shape.  Is it possible to increase only the vertical size (stretch the shape)?  This is during animation of the shape. Problem applying L'Hopitals rule.