Search Results

Search found 44965 results on 1799 pages for 'presenter first'.

Page 434/1799 | < Previous Page | 430 431 432 433 434 435 436 437 438 439 440 441  | Next Page >

  • Unable to delete inherited entity class in EF4

    - by Coding Gorilla
    I have two entities in an EF4 model (using Model First), let's call them EntityA and EntityB. EntityA is marked as abstract, and EntityB inherits from EntityA. They are similar to the following: public class EntityA { public Guid Id; public string Name; public string Uri; } public class EntityB : EntityA { public string AnotherProperty; } The generated database tables look as I would expect them, with EntityA as on table, and then another table like: EntityA_EntityB Id (PK, FK, uniqueidentifier) AnotherProperty (varchar) There is a foreign key constraint on EntityA_EntityB that references EntityA's Id property, no cascades are configured (although I did try changing these myself). The problem is that when I attempt to do something like: Context.DeleteObject(EntityA_EntityB); EF attempts to delete the EntityA_EntityB table record before deleting the EntityA table record, which of course violates the foreign key constraint on EntityA_EntityB table. Using EFProfiler I see the following commands being sent to the database: delete [dbo].[EntityA_EntityB] where (([Id] = '5c02899f-09ea-2ed9-d44b-01aef80f6b64' /* @0 */) followed by delete [dbo].[EntityA] where ([Id] = '5c02899f-09ea-2ed9-d44b-01aef80f6b64' /* @0 */) I'm completely stumped as to how to get around this problem. I would think the EF should know that it needs to delete the base class first, before deleting the inherited class. I know I could do some triggers or other database type solutions, but I'd rather avoid doing that if I can. All my classes are POCO built using some customized T4 templates. I don't want to paste in a lot of extraneous code, but if you need more information I'll provide what I can.

    Read the article

  • My IF statement is changing variables in PHP

    - by user1902509
    I am fairly new to the whole programming thing, so forgive me if this is a stupid question. It seems odd that I haven't run into it before. I am trying to make an order form for a cake. You fill out the form, submit it, and it will then display the order in a new window, where you then hit "submit," and upload it to the Database. I have a series of If Statements to check for errors in the form before submitting it. Here is a simplified version of the code. Writing means any writing you want on the cake, Name is your name, and cake is what type of cake you want (the default is "None"). try { $name = trim($params->name); $cake = trim($params->cake); $writing = trim($params->writing); if (strlen($name) < 3){ throw new Exception("Please enter Your name."); } if ($cake = "None") { throw new Exception("Please select a Cake" } if ($cake = "Caramel Apple Pie" or $cake = "Pumpkin Pie" or $cake = "Eggnog Pie" and strlen($writing) > 1) { throw new Exception("We are sorry, but you can't write on any of our specialty pies."); } } catch(Exception $x) { $error = $x->getmessage(); } So what is happening is that when I go and hit submit the first time, the correct cake type comes up, but when you submit it the second time, the error comes up saying that I have "None" selected. All the other values are there and remain the same. I think the problem is that the first "IF" statement (Where it says "If($cake = "None")) is automatically changing $cake to "None" because I have tried commenting just that statement out, and it will then change the cake to be "Caramel Apple Pie," which is in the top of the next IF statement. Anyone know why it is doing this? And how to fix it?

    Read the article

  • Nested Routes Show Action: What objects does it expect?

    - by NoahClark
    Here is the relevant line from my rake routes: client_note GET /clients/:client_id/notes/:id(.:format) notes#show When I try passing in the objects like <%= client_note_path([client, @notes.first]) %>> I get: No route matches {:action=>"show", :controller=>"notes", :client_id=>[#<Client id: 5, ... , #<Note id: 9, ...]} Which made me think to try a client ID. So, I tried: <%= client_note_path([client.id, @notes.first]) %> which gives me: No route matches {:action=>"show", :controller=>"notes", :client_id=>[5, #<Note id: 9,content: "He just bought a brand new bobcat, be sure to charg...", client_id: 5, created_at: "2012-06-11 16:18:16", updated_at: "2012-06-11 16:18:16">]} Which, made me want to try just passing in a client ID. <%= client_note_path(client.id) %> No route matches {:action=>"show", :controller=>"notes", :client_id=>5} Still not what I'm looking for. I want to be able to show an individual note which can normally be found at a url like looks like: http://localhost:3000/clients/2/notes/3/

    Read the article

  • Slideshow in Javascript without framework, animation?

    - by aaron
    The issue I am having is fairly complicated to explain. I have written up a javascript that displays an image slideshow, and it works fairly well, despite using up more resources than I would like // imgArr[] is populated before var i = 0; var pageLoaded = 0; window.onload = function() {pageLoaded = 1;} function loaded(i,f) { if (document.getElementById(i) != null) f(); else if (!pageLoaded) setTimeout('loaded(\''+i+'\','+f+')',100); } } function displaySlideshow() { document.getElementById(destinationId).innerHTML = '<div id="slideWindow"><img src="'+imgArr[i]+'" />' + '<img src="'+imgArr[i + 1]+'" /></div>'; setTimeout('displaySlideshow()',1000*3); i++; if (i >= imgArr.length - 1) i = 0; } loaded(destinationId,displaySlideshow); So, this script dynamically adds two images to a HTML element, and it is wrapped in a div. The div is styled with the height and width of the image, with the overflow (the second image) hidden. The second image is below the first, and the slideshow is meant to go from RIGHT to LEFT. My inquiry is twofold: 1) Is there a more efficient way of doing this? 2) How would I animate the images? Would I need to put the second image on the right of the first with CSS somehow, and then set a timer to pull the images (via a style) leftward?

    Read the article

  • Catching the return of main function before it deallocates resources

    - by EpsilonVector
    I'm trying to implement user threads in Linux kernel 2.4, and I ran into something problematic and unexpected. Background: a thread basically executes a single function and dies, except that when I call thread_create for the first time it must turn main() into a thread as well (by default it is not a thread until the first call, which is also when all the related data structures are allocated). Since a thread executes a function and dies, we don't need to "return" anywhere with it, but we do need to save the return value to be reclaimed later with thread_join, so the hack I came up with was: when I allocate the thread stack I place a return address that points to a thread_return_handler function, which deallocates the thread, makes it a zombie, and saves its return value for later. This works for "just run a function and die" threads, but is very problematic with the main thread. Since it actually is the main function, if it returns before the other threads finish the normal return mechanism kicks in, and deallocates all the shared resources, thus screwing up all the running threads. I need to keep it from doing that. Any ideas on how it can be done?

    Read the article

  • C++ map to track when the end of map is reached

    - by eNetik
    Currently I have a map that prints out the following map<string, map<int,int> > mapper; map<int,int>::iterator inner; map<string, map<int,int> >::iterator outer; for(outer = mapper.begin(); outer != mapper.end(); outer++){ cout<<outer->first<<": "; for(inner = outer->second.begin(); inner != outer->second.end(); inner++){ cout<<inner->first<<","<<inner->second<<","; } } As of now this prints out the following stringone: 1,2,3,4,6,7,8, stringtwo: 3,5,6,7, stringthree: 2,3,4,5, What i want it to print out is stringone: 1,2,3,4,6,7,8 stringtwo: 3,5,6,7 stringthree: 2,3,4,5 how can i check for the end of the map inside my inner map? Any help would be appreciated Thank you

    Read the article

  • Passing models between controllers in MVC4

    - by wtfsven
    I'm in the middle of my first foray into web development with MVC4, and I've run into a problem that I just know is one of the core issues in web development in general, but can't seem to wrap my mind around it. So I have two models: Employee and Company. Employee has a Company, therefore /Employee/Create contains a field that is either a dropdown list for selecting an existing Company, or an ActionLink to /Company/Create if none exists. But here's the issue: If a user has to create a Company, I need to preserve the existing Employee model across both Views--over to /Company/Create, then back to /Employee/Create. So my first approach was to pass the Employee model to /Company/Create with a @Html.ActionLink("Add...", "Create", "Organization", Model , null), but then when I get to Company's Create(Employee emp), all of emp's values are null. The second problem is that if I try to come back to /Employee/Create, I'd be passing back an Employee, which would resolve to the POST Action. Basically, the whole idea is to save the state of the /Employee/Create page, jump over to /Company/Create to create a Company record, then back to /Employee/Create to finish creating the Employee. I know there is a well understood solution to this because , but I can't seem to phase it well enough to get a good Google result out of it. I've though about using Session, but it seems like doing so would be a bit of a kludge. I'd really like an elegant solution to this.

    Read the article

  • 32-bit JVM on 64-bit Windows crashes on launch with -Xmx1300m and plenty of free memory

    - by Konrad Garus
    I'm struggling with Java heap space settings. The default Java on Windows is the 32-bit client regardless of OS version (that's what Oracle recommends to all users). It appears to set max heap size to 256 MB by default, and that is too little for me. I use a custom launcher to start the application. I would like it to use more memory on computers with plenty RAM, and default to -Xmx512m on those with less RAM. As far as I'm aware, the only way is the static -Xmx setting (that has to be set on launch). I have a user who has 8 GB RAM, 64-bit Windows and 32-bit Java 7. Maximum memory visible to the JVM is 4G (as returned by querying OperatingSystemMXBean). I understand why, no issue. For some reason my application is unable to start for this user with -Xmx1300m, even though he has 2.3G free memory. He closed some applications (having 5G free memory), and still it would not launch. The error reported to me was: error occured during init of vm could not reserve enough space for object heap What's going on? Could it be that the 32-bit JVM is only able to address the "first" 4G of memory and has to have a 1300M block available within those first 4 gigabytes? How can I solve this problem, except for asking everyone to install 64-bit Java (what is unlikely to be acceptable)?

    Read the article

  • Permutations distinct under given symmetry (Mathematica 8 group theory)

    - by Yaroslav Bulatov
    Given a list of integers like {2,1,1,0} I'd like to list all permutations of that list that are not equivalent under given group. For instance, using symmetry of the square, the result would be {{2, 1, 1, 0}, {2, 1, 0, 1}}. Approach below (Mathematica 8) generates all permutations, then weeds out the equivalent ones. I can't use it because I can't afford to generate all permutations, is there a more efficient way? Update: actually, the bottleneck is in DeleteCases. The following list {2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 0, 0, 0} has about a million permutations and takes 0.1 seconds to compute. Apparently there are supposed to be 1292 orderings after removing symmetries, but my approach doesn't finish in 10 minutes removeEquivalent[{}] := {}; removeEquivalent[list_] := ( Sow[First[list]]; equivalents = Permute[First[list], #] & /@ GroupElements[group]; DeleteCases[list, Alternatives @@ equivalents] ); nonequivalentPermutations[list_] := ( reaped = Reap@FixedPoint[removeEquivalent, Permutations@list]; reaped[[2, 1]] ); group = DihedralGroup[4]; nonequivalentPermutations[{2, 1, 1, 0}]

    Read the article

  • VB6 ActiveX exe - what is the proper registration sequence?

    - by Timbuck
    I have recently updated a Visual Basic 6 application that is an ActiveX exe, running on Windows XP. I have a couple of testers for this application who have received a copy of the exe and are attempting to run it. However, they are getting an error message "Unexpected error;quitting" when trying to do so. A key difference between their testing and my testing is that on the machines I tested on, I have admin rights and was able to register the application using the appname.exe /regserver command line. Reading the details at MS Support about file registration appears unclear: Visual Basic ActiveX EXE files register themselves the first time you run the EXE. However, you cannot use the EXE as a COM server until it is registered. So does this mean that after the first time the users run the exe that the application should be correctly registered, and the error I am receiving is sign of something other than an incorrectly registered application? Or does this mean that the application will not work properly until such time as the file is explicitly registered using the appname.exe /regserver command line? nb - during a production distribution, the software would be sent out to client PCs using Systems Management Server, which isn't an option for this testing.

    Read the article

  • Is there any time estimation about sqlite3's open speed?

    - by sxingfeng
    I am using SQLite3 in C++, I found the opening time of sqlite seems unstable at the first time( I mean ,open windows and open the db at the first time) It takes a long tiom on 50M db, about 10s in windows? and vary on different times. Has any one met the same problem? I am writting an desktop application in windows, so the openning speed is really important for me. Thanks in advance! int nRet; #if defined(_UNICODE) || defined(UNICODE) nRet = sqlite3_open16(szFile, &mpDB); // not tested under window 98 #else // For Ansi Version //*************- Added by Begemot szFile must be in unicode- 23/03/06 11:04 - **** OSVERSIONINFOEX osvi; ZeroMemory(&osvi, sizeof(OSVERSIONINFOEX)); osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFOEX); GetVersionEx ((OSVERSIONINFO *) &osvi); if ( osvi.dwMajorVersion == 5) { WCHAR pMultiByteStr[MAX_PATH+1]; MultiByteToWideChar( CP_ACP, 0, szFile, _tcslen(szFile)+1, pMultiByteStr, sizeof(pMultiByteStr)/sizeof(pMultiByteStr[0]) ); nRet = sqlite3_open16(pMultiByteStr, &mpDB); } else nRet = sqlite3_open(szFile,&mpDB); #endif //************************* if (nRet != SQLITE_OK) { LPCTSTR szError = (LPCTSTR) _sqlite3_errmsg(mpDB); throw CppSQLite3Exception(nRet, (LPTSTR)szError, DONT_DELETE_MSG); } setBusyTimeout(mnBusyTimeoutMs);

    Read the article

  • Copy a LinkedList that has a Random Pointer in it

    - by Bragaadeesh
    Hi, First of all this is not a homework, this is an interview question that I got from a company I attended today. You have a singly linked list with the Node structure as the following class Node{ int data; Node next; Node random; } You have a typical singly linked list of length n. The random pointer in each node in the linkedlist randomly points to some Node within the linked list. The Question is to create a copy of the linked list efficiently into a different LinkedList. I said that I will first calculate the Random pointer's position in the linked list and store it in an array. Then create a new linked list normally. Then iterate through the linked list by setting the random pointer where they belong by reading the values stored from the array. I know its a very brute force technique and the interviewer asked me to come up with a better solution but I couldnt. Please can someone answer this? I can explain if the question is not clear.

    Read the article

  • How to find the closest descendants (that matches a selector) with jQuery?

    - by powerboy
    We can use closest(selector) to find the first ancestor element that matches the selector. It travels up the DOM tree until it finds a match for the selector. But what if I want to travels down the DOM tree until it finds a match for the selector? Is there any jQuery function for doing this? Or do I need to implement this using breadth-first search? Give an example. For the DOM tree below, <div id="main"> <div> <ul><!-- I want to match this ul --> <li> <ul><!-- but not this ul --> </ul> </li> </ul> <ul><!-- and match this ul --> </ul> </div> </div> how to do something like $('#main').closestDescendants('ul')?

    Read the article

  • Jquery ajax ($.ajax) not working on chrome. please help

    - by racky
    Hi, I need a little help to figure out why the following code does not work on google chrome 5/windows xp. It works well on all other browsers (IE, FF, Safri, Opera etc). Can someone shed some light around this? /* AJAX Request */ jq("#a-post-request").unbind("click").bind("click", function(e){ //jq("#loading").css({"display":"block"}); jq.ajax({ url: "search_data_table.html", type: "get", cache: false, error: function(){alert ("No data found for your search.");}, success: function(data){ jq("#search-results-table tbody").empty().append(data); jq("#search-results").css({"display":"block"}); jq("#search-results-table").trigger("update"); // this one is for the table sorter plugin // set sorting column and direction, this will sort on the first column. var sorting = [[0,0]];// this one is for the table sorter plugin // sort on the first column . jq("#search-results-table").trigger("sorton",[sorting]);// this one is for the table sorter plugin e.preventDefault(); } }); }); Many thanks, Racky

    Read the article

  • jQuery Fancy - popup window doesn't fully expand

    - by fmz
    I am using jQuery Fancybox to display a number of Flash videos on a site and I am having trouble with the window not opening fully on the first click in Firefox. It works fine in other browsers. Here is the jQuery: <script type="text/javascript"> $(document).ready(function() { $("a.videoLink").fancybox({ 'titleShow' : false, 'autoscale' : true, 'width' : '820', 'height' : '620', 'transitionIn' : 'elastic', 'transitionOut' : 'elastic' }); }); </script> Here is the html: <tr> <td class="title"><a class="videoLink" href="#video-content30">CPR Lesson 1 Movie</a></td> <td class="time">38:39</td> <td class="video" style="display:none"> <div id="video-content30"> <script type='text/javascript'> var flashvars = { file: 'http://www.stockmarketcpr.com/smsys/link/CPR-Lesson-1-Movie.flv', id: '30' }; var params = { wmode: 'opaque', bgcolor: '#CCCCCC', allowfullscreen: 'true', allowscriptaccess: 'always' }; swfobject.embedSWF('http://www.stockmarketcpr.com/_flash/player.swf', 'player30','800','600', '9.0.0','expressInstall.swf', flashvars, params); </script> <div id="player30"></div> </div> </td> </tr> I end up getting a quarter inch high, full-width window on the first click. The second click plays fine. I would appreciate any assistance. Thank you!

    Read the article

  • Java Graphics not displaying on successive function calls, why?

    - by primehunter326
    Hi, I'm making a visualization for a BST implementation (I posted another question about it the other day). I've created a GUI which displays the viewing area and buttons. I've added code to the BST implementation to recursively traverse the tree, the function takes in coordinates along with the Graphics object which are initially passed in by the main GUI class. My idea was that I'd just have this function re-draw the tree after every update (add, delete, etc...), drawing a rectangle over everything first to "refresh" the viewing area. This also means I could alter the BST implementation (i.e by adding a balance operation) and it wouldn't affect the visualization. The issue I'm having is that the draw function only works the first time it is called, after that it doesn't display anything. I guess I don't fully understand how the Graphics object works since it doesn't behave the way I'd expect it to when getting passed/called from different functions. I know the getGraphics function has something to do with it. Relevant code: private void draw(){ Graphics g = vPanel.getGraphics(); tree.drawTree(g,ORIGIN,ORIGIN); } vPanel is what I'm drawing on private void drawTree(Graphics g, BinaryNode<AnyType> n, int x, int y){ if( n != null ){ drawTree(g, n.left, x-10,y+10 ); if(n.selected){ g.setColor(Color.blue); } else{ g.setColor(Color.gray); } g.fillOval(x,y,20,20); g.setColor(Color.black); g.drawString(n.element.toString(),x,y); drawTree(g,n.right, x+10,y+10); } } It is passed the root node when it is called by the public function. Do I have to have: Graphics g = vPanel.getGraphics(); ...within the drawTree function? This doesn't make sense!! Thanks for your help.

    Read the article

  • Filtering string in Python

    - by Ecce_Homo
    I am making algorithm for checking the string (e-mail) - like "E-mail addres is valid" but their are rules. First part of e-mail has to be string that has 1-8 characters (can contain alphabet, numbers, underscore [ _ ]...all the parts that e-mail contains) and after @ the second part of e-mail has to have string that has 1-12 characters (also containing all legal expressions) and it has to end with top level domain .com EDIT email = raw_input ("Enter the e-mail address:") length = len (email) if length > 20 print "Address is too long" elif lenght < 5: print "Address is too short" if not email.endswith (".com"): print "Address doesn't contain correct domain ending" first_part = len (splitting[0]) second_part = len(splitting[1]) account = splitting[0] domain = splitting[1] for c in account: if c not in "abcdefghijklmopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_.": print "Invalid char", "->", c,"<-", "in account name of e-mail" for c in domain: if c not in "abcdefghijklmopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_.": print "Invalid char", "->", c,"<-", "in domain of e-mail" if first_part == 0: print "You need at least 1 character before the @" elif first_part> 8: print "The first part is too long" if second_part == 4: print "You need at least 1 character after the @" elif second_part> 16: print "The second part is too long" else: # if everything is fine return this print "E-mail addres is valid" EDIT: After reproting what is wrong with our input, now I need to make Python recognize valid address and return ("E-mail adress is valid") This is the best i can do with my knowledge....and we cant use regular expressions, teacher said we are going to learn them later.

    Read the article

  • Anyone Experiencing Slow Builds With VS2010?

    - by MrKWatkins
    Hi, We've recently upgraded to the final release of VS2010 and are experiencing very slow build times compared to the same code under 2008. I was wondering if anyone else is experiencing the same so I can work out whether it's just our environment or not? A few details: Using VS2010 Ultimate on Windows 7 with fairly beefy machines, talking to TFS 2010. The solution has been upgraded from VS2008 but still builds against .NET 3.5 and ASP.NET MVC 1.0. It doesn't seem to be the compilation itself taking long but something else in the build process. This is because even projects that are up to date and don't need compiling are taking a few seconds or so to process. It's not due to an Visual Studio addin because a couple guys in the team haven't installed any. The first build after loading VS2010 is pretty quick, then they seem to slow down over time. For example on of the projects in my solution just took 00:00:00.08 to process after a restart. (The project was up to date and didn't need compiling) I then immediately hit rebuild and it jumps to 00:00:01.33. We're also experiencing the problem with another solution that uses .NET 4.0 that was building perfectly fine under VS2010 RC. There are no build events or anything like that I can blame, just straightforward assembly builds. The IDE is not very responsive during the slow builds. Anyone else has similar problems? Update: It looks like the resolving assembly references is taking a long time. Looking at the MSBuild diagnostic output or the example above the first build has 30ms for ResolveAssemblyReferences, the second build has 800ms. Subsequent builds seem to be taking longer copying stuff around, e.g. CopyFilesToOutputDirectory jumps from 1ms to 27ms.

    Read the article

  • Is there a proper and wrong way to format CSS?

    - by DavidR
    When I first started writing CSS, I was writing it in an expanded form div.class { margin: 10px 5px 3px; border: 1px solid #333; font-weight: bold; } .class .subclass { text-align:right; } but now I find myself writing css like this: (Example from code I'm actually writing now) .object1 {} .scrollButton{width:44px;height:135px;} .scrollButton img {padding:51px 0 0 23px;} .object2 {width:165px;height:94px;margin:15px 0 0 23px;padding:15px 0 0 10px;background:#fff;} .featuredObject .symbol{line-height:30px; padding-top:6px;} .featuredObject .value {width:90px;} .featuredObject .valueChange {padding:5px 0 0 0;} .featuredObject img {position:absolute;margin:32px 0 0 107px;} and I'm beginning to worry because a lot of the time I see the first form done in examples online, while I find the second form a lot easier for me to work with. It has a lower vertical height, so I can see all the classes at a glance with less scrolling, the tabulation of the hierarchy seems more apparent, and it looks more like code I'd write with javascript or html. Is this a valid way of doing code, or to keep with standards when putting it online should I use the vertical form instead?

    Read the article

  • C# ? Can anyone explain the strange behaviour?

    - by partizan
    Hi, guys. Here is the example with comments: class Program { // first version of structure public struct D1 { public double d; public int f; } // during some changes in code then we got D2 from D1 // Field f type became double while it was int before public struct D2 { public double d; public double f; } static void Main(string[] args) { // Scenario with the first version D1 a = new D1(); D1 b = new D1(); a.f = b.f = 1; a.d = 0.0; b.d = -0.0; bool r1 = a.Equals(b); // gives true, all is ok // The same scenario with the new one D2 c = new D2(); D2 d = new D2(); c.f = d.f = 1; c.d = 0.0; d.d = -0.0; bool r2 = c.Equals(d); // false, oops! this is not the result i've expected for } } So, what do you think about this?

    Read the article

  • std::map keys in C++

    - by Soumava
    I have a requirement to create two different maps in C++. The Key is of type CHAR * and the Value is a pointer to a struct. I am filling 2 maps with these pairs, in separate iterations. After creating both maps I need find all such instances in which the value of the string referenced by the CHAR * are same. For this i am using the following code : typedef struct _STRUCTTYPE { .. } STRUCTTYPE, *PSTRUCTTYPE; typedef pair {CHAR *,PSTRUCTTYPE} kvpair; .. CHAR *xyz; PSTRUCTTYPE abc; after filling the information; Map.insert (kvpair(xyz,abc)); the above is repeated x times for the first map, and y times for the second map. after both are filled out; std::map {CHAR *, PSTRUCTTYPE} :: iterator Iter,findIter; for (Iter=iteratedMap-begin();Iter!=iteratedMap-end();mapIterator++) { char *key = Iter-first; printf("%s\n",key); findIter=otherMap-find(key); //printf("%u",findIter-second); if (findIter!=otherMap-end()) { printf("Match!\n"); } } The above code does not show any match, although the list of keys in both maps show obvious matches. My understanding is that the equals operator for CHAR * just equates the memory address of the pointers. My question is, what should i do to alter the equals operator for this type of key or could I use a different datatype for the string? *note : {} has been used instead of angle brackets as the content inside angle brackets was not showing up in the post.

    Read the article

  • User Defined Conversions in C++

    - by wash
    Recently, I was browsing through my copy of the C++ Pocket Reference from O'Reilly Media, and I was surprised when I came across a brief section and example regarding user-defined conversion for user-defined types: #include <iostream> class account { private: double balance; public: account (double b) { balance = b; } operator double (void) { return balance; } }; int main (void) { account acc(100.0); double balance = acc; std::cout << balance << std::endl; return 0; } I've been programming in C++ for awhile, and this is the first time I've ever seen this sort of operator overloading. The book's description of this subject is somewhat brief, leaving me with a few unanswered questions about this feature: Is this a particularly obscure feature? As I said, I've been programming in C++ for awhile and this is the first time I've ever come across this. I haven't had much luck finding more in-depth material regarding this. Is this relatively portable? (I'm compiling on GCC 4.1) Can user-defined conversions to user defined types be done? e.g. operator std::string () { /* code */ }

    Read the article

  • lapply slower than for-loop when used for a BiomaRt query. Is that expected?

    - by ptocquin
    I would like to query a database using BiomaRt package. I have loci and want to retrieve some related information, let say description. I first try to use lapply but was surprise by the time needed for the task to be performed. I thus tried a more basic for-loop and get a faster result. Is that expected or is something wrong with my code or with my understanding of apply ? I read other posts dealing with *apply vs for-loop performance (Here, for example) and I was aware that improved performance should not be expected but I don't understand why performance here is actually lower. Here is a reproducible example. 1) Loading the library and selecting the database : library("biomaRt") athaliana <- useMart("plants_mart_14") athaliana <- useDataset("athaliana_eg_gene",mart=athaliana) 2) Querying the database : loci <- c("at1g01300", "at1g01800", "at1g01900", "at1g02335", "at1g02790", "at1g03220", "at1g03230", "at1g04040", "at1g04110", "at1g05240" ) I create a function for the use in lapply : foo <- function(loci) { getBM("description","tair_locus",loci,athaliana) } When I use this function on the first element : > system.time(foo(cwp_loci[1])) utilisateur système écoulé 0.020 0.004 1.599 When I use lapply to retrieve the data for all values : > system.time(lapply(loci, foo)) utilisateur système écoulé 0.220 0.000 16.376 I then created a new function, adding a for-loop : foo2 <- function(loci) { for (i in loci) { getBM("description","tair_locus",loci[i],athaliana) } } Here is the result : > system.time(foo2(loci)) utilisateur système écoulé 0.204 0.004 10.919 Of course, this will be applied to a big list of loci, so the best performing option is needed. I thank you for assistance. EDIT Following recommendation of @MartinMorgan Simply passing the vector loci to getBM greatly improves the query efficiency. Simpler is better. > system.time(lapply(loci, foo)) utilisateur système écoulé 0.236 0.024 110.512 > system.time(foo2(loci)) utilisateur système écoulé 0.208 0.040 116.099 > system.time(foo(loci)) utilisateur système écoulé 0.028 0.000 6.193

    Read the article

  • implementation musical instrument using audio unit

    - by Develop.Kim
    post same question at apple developer forum ,too hi first sorry that my english is poor.. i want develop iphone application that playing musical instrument like 'ocarina' but don't need blow mic features. so first i tried to find that how implementation 'virtual musical instrument ' in iphone development. the during the decide implementation using 'Audio Unit' to report this article (link) so i want two kind of questions. i recognize that the 'musical instrument' can be divided into three sound that 'attack', 'sustain' , 'release'. 'decay' maybe included (link) . How implementation when audio unit base 'AUInstrumentBase' each sound ? i download sample 'SinSynth' (link) . i want play note this instrument unit for analyze source and study. Is there way to using AULab? expected the way using MIDI input . but i don't have MIDI. in addition, i wonder that i would think it right the way. to ask the advice... thank for reading poor english my article.

    Read the article

  • hasAndBelongsToMany only working one way

    - by Cameron
    In my application I have users that are able to be friends with other users. This is controlled with a users table and a friends_users table. The friends_users table has the following columns: id, user_id, friend_id, status And the model User looks like: public $hasAndBelongsToMany = array( 'Friend'=>array( 'className' => 'User', 'joinTable' => 'friends_users', 'foreignKey' => 'user_id', 'associationForeignKey' => 'friend_id' ) ); This seems to work fine when viewing the Users for a user who is in the user_id column, but doesn't work the other way around, i.e. in reverse... Any ideas why? Here is the method I use to list the friends for a user: $user = $this->User->find('first', array( 'conditions' => array('User.id' => $this->Auth->user('id')), 'contain'=>'Profile' )); $friends = $this->User->find('first', array( 'conditions'=>array( 'User.id'=>$user['User']['id'] ), 'contain'=>array( 'Profile', 'Friend'=>array( 'Profile', 'conditions'=>array( 'FriendsUser.status'=>1 ) ) ) ) ); $this->set('friends', $friends);

    Read the article

< Previous Page | 430 431 432 433 434 435 436 437 438 439 440 441  | Next Page >