Search Results

Search found 19393 results on 776 pages for 'reference count'.

Page 626/776 | < Previous Page | 622 623 624 625 626 627 628 629 630 631 632 633  | Next Page >

• Trying to calculate large numbers in Python with gmpy. Python keeps crashing?

  - by Ryan Peschel

  I was recommended to use gmpy to assist with calculating large numbers efficiently. Before I was just using python and my script ran for a day or two and then ran out of memory (not sure how that happened because my program's memory usage should basically be constant throughout.. maybe a memory leak?) Anyways, I keep getting this weird error after running my program for a couple seconds: mp_allocate< 545275904->545275904 > Fatal Python error: mp_allocate failure This application has requested the Runtime to terminate it in an unusual way. Please contact the application's support team for more information. Also, python crashes and Windows 7 gives me the generic python.exe has stopped working dialog. This wasn't happening with using standard python integers. Now that I switch to gmpy I am getting this error just seconds in to running my script. I thought gmpy was specialized in dealing with large number arithmetic? For reference, here is a sample program that produces the error: import gmpy2 p = gmpy2.xmpz(3000000000) s = gmpy2.xmpz(2) M = s**p for x in range(p): s = (s * s) % M I have 10 gigs of RAM and without gmpy this script ran for days without running out of memory (still not sure how that happened considering s never really gets larger.. Anyone have any ideas? EDIT: Forgot to mention I am using Python 3.2

  Read the article

• Magi squares, recursive

  - by user310827

  Hi, my problem is, I'm trying to permute all posibilities for 3x3 square and check if the combination is magic. I've added a tweak with (n%3==0) if statement that if the sum of numbers in row differs from 15 it breaks the creation of other two lines... but it doesn't work, any suggestions, I call the function with Permute(1). public static class Global { //int[] j = new int[6]; public static int[] a= {0,0,0,0,0,0,0,0,0}; public static int[] b= {0,0,0,0,0,0,0,0,0}; public static int count = 0; } public static void Permute(int n) { int tmp=n-1; for (int i=0;i<9;i++){ if (Global.b[i]==0 ) { Global.b[i]=1; Global.a[n-1]=i+1; if ((n % 3) == 0) { if (Global.a[0+tmp]+Global.a[1+tmp]+Global.a[2+tmp] == 15) { if (n<9) { Permute(n+1); } else { isMagic(Global.a); } } else break; } else { Permute(n+1); } Global.b[i]=0; } } }

  Read the article

• C++ Multiple inheritance with interfaces?

  - by umanga

  Greetings all, I come from Java background and I am having difficulty with multiple inheritance. I have an interface called IView which has init() method.I want to derive a new class called PlaneViewer implementing above interface and extend another class. (QWidget). My implementation is as: IViwer.h (only Header file , no CPP file) : #ifndef IVIEWER_H_ #define IVIEWER_H_ class IViewer { public: //IViewer(); ///virtual //~IViewer(); virtual void init()=0; }; #endif /* IVIEWER_H_ */ My derived class. PlaneViewer.h #ifndef PLANEVIEWER_H #define PLANEVIEWER_H #include <QtGui/QWidget> #include "ui_planeviewer.h" #include "IViewer.h" class PlaneViewer : public QWidget , public IViewer { Q_OBJECT public: PlaneViewer(QWidget *parent = 0); ~PlaneViewer(); void init(); //do I have to define here also ? private: Ui::PlaneViewerClass ui; }; #endif // PLANEVIEWER_H PlaneViewer.cpp #include "planeviewer.h" PlaneViewer::PlaneViewer(QWidget *parent) : QWidget(parent) { ui.setupUi(this); } PlaneViewer::~PlaneViewer() { } void PlaneViewer::init(){ } My questions are: Is it necessary to declare method init() in PlaneViewer interface also , because it is already defined in IView? 2.I cannot complie above code ,give error : PlaneViewer]+0x28): undefined reference to `typeinfo for IViewer' collect2: ld returned 1 exit status Do I have to have implementation for IView in CPP file?

  Read the article

• PHP: Next Available Value in an Array, starting with a non-indexed value

  - by Erik Smith

  I've been stumped on this PHP issue for about a day now. Basically, we have an array of hours formatted in 24-hour format, and an arbitrary value ($hour) (also a 24-hour). The problem is, we need to take $hour, and get the next available value in the array, starting with the value that immediately proceeds $hour. The array might look something like: $goodHours = array('8,9,10,11,12,19,20,21). Then the hour value might be: $hour = 14; So, we need some way to know that 19 is the next best time. Additionally, we might also need to get the second, third, or fourth (etc) available value. The issue seems to be that because 14 isn't a value in the array, there is not index to reference that would let us increment to the next value. To make things simpler, I've taken $goodHours and repeated the values several times just so I don't have to deal with going back to the start (maybe not the best way to do it, but a quick fix). I have a feeling this is something simple I'm missing, but I would be so appreciative if anyone could shed some light. Erik

  Read the article

• Rails - eager load the number of associated records, but not the record themselves.

  - by Max Williams

  I have a page that's taking ages to render out. Half of the time (3 seconds) is spent on a .find call which has a bunch of eager-loaded associations. All i actually need is the number of associated records in each case, to display in a table: i don't need the actual records themselves. Is there a way to just eager load the count? Here's a simplified example: @subjects = Subject.find(:all, :include => [:questions]) In my table, for each row (ie each subject) i just show the values of the subject fields and the number of associated questions for each subject. Can i optimise the above find call to suit these requirements? I thought about using a group field but my full call has a few different associations included, with some second-order associations, so i don't think group by will work. @subjects = Subject.find(:all, :include => [{:questions => :tags}, {:quizzes => :tags}], :order => "subjects.name") :tags in this case is a second-order association, via taggings. Here's my associations in case it's not clear what's going on. Subject has_many :questions has_many :quizzes Question belongs_to :subject has_many :taggings has_many :tags, :through => :taggings Quiz belongs_to :subject has_many :taggings has_many :tags, :through => :taggings Grateful for any advice - max

  Read the article

• how to find a control inside ItemsPanelTemplate in wpf?

  - by kakopappa

  I am trying to access a Grid inside the DataTemplate while the ItemsControl is binded by ItemsSource. this is the full XMAL code, How do i find a certain element from outside? for (int i = 0; i < allViewControl.Items.Count; i++) { var container = allViewControl.ItemContainerGenerator.ContainerFromItem(allViewControl.Items[i]) as FrameworkElement; var grid = allViewControl.ItemTemplate.FindName("grid", container) as DataGrid; } i found this always returning null ? <ScrollViewer Grid.Row="0" HorizontalScrollBarVisibility="Disabled" VerticalScrollBarVisibility="Auto"> <ItemsControl x:Name="allViewControl" Focusable="False" HorizontalContentAlignment="Center" Grid.IsSharedSizeScope="true" ItemsSource="{Binding AllClassCharacters}" ItemTemplate="{StaticResource CharacterViewModelTemplate}" > <ItemsControl.ItemsPanel> <ItemsPanelTemplate> <Extensions:AnimatedWrapPanel IsItemsHost="true" /> </ItemsPanelTemplate> </ItemsControl.ItemsPanel> </ItemsControl> </ScrollViewer> <DataTemplate x:Key="CharacterViewModelTemplate" DataType="{x:Type ViewModel:CharacterViewModel}"> <Grid x:Name="grid" Width="200" Height="Auto" MinHeight="115" Margin="1" MinWidth="130" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" RenderTransformOrigin="0.5,0.5" Background="#66000000" > <Grid.RowDefinitions> <RowDefinition Height="70"/> <RowDefinition Height="*"/> </Grid.RowDefinitions> <Grid.ColumnDefinitions> <ColumnDefinition Width="*" /> <ColumnDefinition Width="*" /> </Grid.ColumnDefinitions> <ProgressBar x:Name="playerProgressBar" VerticalAlignment="Top" Background="Transparent" Height="5" Width="Auto" Value="0" Visibility="Collapsed" Grid.Column="0" Grid.Row="0" Grid.ColumnSpan ="2" Grid.RowSpan="2" Foreground="White" BorderThickness="0" Style="{DynamicResource ProgressBarStyle1}" /> </Grid>

  Read the article

• Using the Proxy pattern with C++ iterators

  - by Billy ONeal

  Hello everyone :) I've got a moderately complex iterator written which wraps the FindXFile apis on Win32. (See previous question) In order to avoid the overhead of constructing an object that essentially duplicates the work of the WIN32_FIND_DATAW structure, I have a proxy object which simply acts as a sort of const reference to the single WIN32_FIND_DATAW which is declared inside the noncopyable innards of the iterator. This is great because Clients do not pay for construction of irrelevant information they will probably not use (most of the time people are only interested in file names), and Clients can get at all the information provided by the FindXFile APIs if they need or want this information. This becomes an issue though because there is only ever a single copy of the object's actual data. Therefore, when the iterator is incrememnted, all of the proxies are invalidated (set to whatever the next file pointed to by the iterator is). I'm concerned if this is a major problem, because I can think of a case where the proxy object would not behave as somebody would expect: std::vector<MyIterator::value_type> files; std::copy(MyIterator("Hello"), MyIterator(), std::back_inserter(files)); because the vector contains nothing but a bunch of invalid proxies at that point. Instead, clients need to do something like: std::vector<std::wstring> filesToSearch; std::transform( DirectoryIterator<FilesOnly>(L"C:\\Windows\\*"), DirectoryIterator<FilesOnly>(), std::back_inserter(filesToSearch), std::mem_fun_ref(&DirectoryIterator<FilesOnly>::value_type::GetFullFileName) ); Seeing this, I can see why somebody might dislike what the standard library designers did with std::vector<bool>. I'm still wondering though: is this a reasonable trade off in order to achieve (1) and (2) above? If not, is there any way to still achieve (1) and (2) without the proxy?

  Read the article

• populate textboxs with xml node attributes

  - by Doug

  I have Data.xml: <?xml version="1.0" encoding="utf-8" ?> <data> <album> <slide title="Autum Leaves" description="Leaves from the fall of 1986" source="images/Autumn Leaves.jpg" thumbnail="images/Autumn Leaves_thumb.jpg" /> <slide title="Creek" description="Creek in Alaska" source="images/Creek.jpg" thumbnail="images/Creek_thumb.jpg" /> </album> </data> I'd like to be able to edit the attributes of each Slide node via GridView (that has a "Select" column added.) And so far I have: protected void GridView1_SelectedIndexChanged(object sender, EventArgs e) { int selectedIndex = GridView1.SelectedIndex; LoadXmlData(selectedIndex); } private void LoadXmlData(int selectedIndex) { XmlDocument xmldoc = new XmlDocument(); xmldoc.Load(MapPath(@"..\photo_gallery\Data.xml")); XmlNodeList nodelist = xmldoc.DocumentElement.ChildNodes; XmlNode xmlnode = nodelist.Item(selectedIndex); titleTextBox.Text = xmlnode.Attributes["title"].InnerText; descriptionTextBox.Text = xmlnode.Attributes["description"].InnerText; sourceTextBox.Text = xmlnode.Attributes["source"].InnerText; thumbTextBox.Text = xmlnode.Attributes["thumbnail"].InnerText; The code for LoadXmlData is just a guess on my part - I'm new to working with xml in this way. I'd like have the user to slected the row from the gridview, then populate a set of text boxes with each slide attributed for updating back to the Data.xml file. The error I'm getting is "Object reference not set to an instance of an object" at the line: titleTextBox.Text = xmlnode.Attributes["@title"].InnerText; - so I'm not reaching the attribute "title" of the slide node. Thanks for any ideas you may have.

  Read the article

• SQLite for personal use

  - by ALife

  What are the applications for your personal use that needs a small database like SQLite? I am thinking of trying a few popular databases and SQLite is surely the first one I am planning to try since I know barely nothing about database except some simple programming years ago. I learned that SQLite is good for personal use. But embarrassingly I do not see any application except maybe managing my list of phone numbers/contact info, which has probably a few hundred items. What's your experience? FYI, I use EndNote for my reference and softcopy of books, and I feel iTunes' music/media management is ok since I am not a frequent user anyway. And others? I do lots of coding, but I just use some simple etags tools for that. And I pretty much use .txt file (sometimes in the asciidoc style) for my notes. I have quite a bunch of notes, but not that many either. So, really, what are your personal applications that need a small database instead of existing tools and plain text files?

  Read the article

• Servlet Mapping Help - Possible to Avoid Referencing Context Name?

  - by AJ

  Hi all, I am working on a Spring application and trying to get my URL mapping correct. What I would like to have work is the following: http://localhost:8080/idptest -> doesn't work But instead, I have to reference the context name in my URL in order to resolve the mapping: http://localhost:8080/<context_name>/idptest -> works How can I avoid the requirement of referencing the context name in my URL without using a rewrite/proxy engine e.g. Apache? Here is the servlet definition and mapping from my web.xml: <servlet> <servlet-name>idptest</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/conf/idptest.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>idptest</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> Here's the outline of my controller (showing annotations for request mappings): @Controller @RequestMapping("/idptest") public class MyController { @RequestMapping(method=RequestMethod.GET) public String setupForm(Model model){ MyObject someObject = new MyObject(); model.addAttribute("someObject", someObject); return "myform"; } @RequestMapping(method = RequestMethod.POST) public String processSubmit(@ModelAttribute("someObject") MyObject someObject) throws Exception { // POST logic... } } Thanks!

  Read the article

• Strange XCode debugger behavior with UITableView datasource

  - by Tarfa

  Hey guys. I've got a perplexing issue. In my subclassed UITableViewController my datasource methods lose their tableview reference depending on lines of code I put inside the method. For example, in this code block: - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { // Return the number of sections. return 3; } - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { // Return the number of rows in the section. return 5; } // Customize the appearance of table view cells. - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { id i = tableView; static NSString *CellIdentifier = @"Cell"; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease]; } // Configure the cell... return cell; } the "id i = tableView;" causes the tableview to become nil (0x0) -- and it causes it to be nil before I ever start stepping into the method. If I insert an assignment statement above the "id i = tableview;" statement: CGFloat x = 5.0; id i = tableView; then tableview retains its pointer (i.e. is not nil) if I place the breakpoint after the "id i = tableView;" line. In other words, the breakpoint must be set after the "id i = tableView"; assignment in order for tableView to retain its pointer. If the breakpoint is set before the assignment is made and I just hang at that breakpoint for a bit then after a couple of seconds the console logs this error message: Assertion failed: (cls), function getName, file /SourceCache/objc4_Sim/objc4-427.5/runtime/objc-runtime-new.mm, line 3990. Although the code works when I don't step through the method, I need my debugger to work! It makes programming kind of challenging when your debugging tools become your enemy. Anyone know what the cause and solution are? Thanks.

  Read the article

• Convert SQL with Inner AND Outer Join to L2S

  - by Refracted Paladin

  I need to convert the below Sproc to a Linq query. At the very bottom is what I have so far. For reference the fields behind the "splat"(not my sproc) are ImmunizationID int, HAReviewID int, ImmunizationMaintID int, ImmunizationOther varchar(50), ImmunizationDate smalldatetime, ImmunizationReasonID int The first two are PK and FK, respectively. The other two ints are linke to the Maint Table where there description is stored. That is what I am stuck on, the INNER JOIN AND the LEFT OUTER JOIN Thanks, SELECT tblHAReviewImmunizations.*, tblMaintItem.ItemDescription, tblMaintItem2.ItemDescription as Reason FROM dbo.tblHAReviewImmunizations INNER JOIN dbo.tblMaintItem ON dbo.tblHAReviewImmunizations.ImmunizationMaintID = dbo.tblMaintItem.ItemID LEFT OUTER JOIN dbo.tblMaintItem as tblMaintItem2 ON dbo.tblHAReviewImmunizations.ImmunizationReasonID = tblMaintItem2.ItemID WHERE HAReviewID = @haReviewID My attempt so far -- public static DataTable GetImmunizations(int haReviewID) { using (var context = McpDataContext.Create()) { var currentImmunizations = from haReviewImmunization in context.tblHAReviewImmunizations where haReviewImmunization.HAReviewID == haReviewID join maintItem in context.tblMaintItems on haReviewImmunization.ImmunizationReasonID equals maintItem.ItemID into g from maintItem in g.DefaultIfEmpty() let Immunization = GetImmunizationNameByID( haReviewImmunization.ImmunizationMaintID) select new { haReviewImmunization.ImmunizationDate, haReviewImmunization.ImmunizationOther, Immunization, Reason = maintItem == null ? " " : maintItem.ItemDescription }; return currentImmunizations.CopyLinqToDataTable(); } } private static string GetImmunizationNameByID(int? immunizationID) { using (var context = McpDataContext.Create()) { var domainName = from maintItem in context.tblMaintItems where maintItem.ItemID == immunizationID select maintItem.ItemDescription; return domainName.SingleOrDefault(); } }

  Read the article

• Creating a blocking Queue<T> in .NET?

  - by spoon16

  I have a scenario where I have multiple threads adding to a queue and multiple threads reading from the same queue. If the queue reaches a specific size all threads that are filling the queue will be blocked on add until an item is removed from the queue. The solution below is what I am using right now and my question is: How can this be improved? Is there an object that already enables this behavior in the BCL that I should be using? internal class BlockingCollection<T> : CollectionBase, IEnumerable { //todo: might be worth changing this into a proper QUEUE private AutoResetEvent _FullEvent = new AutoResetEvent(false); internal T this[int i] { get { return (T) List[i]; } } private int _MaxSize; internal int MaxSize { get { return _MaxSize; } set { _MaxSize = value; checkSize(); } } internal BlockingCollection(int maxSize) { MaxSize = maxSize; } internal void Add(T item) { Trace.WriteLine(string.Format("BlockingCollection add waiting: {0}", Thread.CurrentThread.ManagedThreadId)); _FullEvent.WaitOne(); List.Add(item); Trace.WriteLine(string.Format("BlockingCollection item added: {0}", Thread.CurrentThread.ManagedThreadId)); checkSize(); } internal void Remove(T item) { lock (List) { List.Remove(item); } Trace.WriteLine(string.Format("BlockingCollection item removed: {0}", Thread.CurrentThread.ManagedThreadId)); } protected override void OnRemoveComplete(int index, object value) { checkSize(); base.OnRemoveComplete(index, value); } internal new IEnumerator GetEnumerator() { return List.GetEnumerator(); } private void checkSize() { if (Count < MaxSize) { Trace.WriteLine(string.Format("BlockingCollection FullEvent set: {0}", Thread.CurrentThread.ManagedThreadId)); _FullEvent.Set(); } else { Trace.WriteLine(string.Format("BlockingCollection FullEvent reset: {0}", Thread.CurrentThread.ManagedThreadId)); _FullEvent.Reset(); } } }

  Read the article

• Loading enumerations from database

  - by Mosh

  Hello, I have a problem with mapping .NET enumerations to database tables. Imagine I have a table called Statuses with the following values: StatusID | Name 1 Draft 2 Ready ... ... In the application layer, I can either use a Repository to get all Statuses as an IList object. However, the problem with this approach is that I cannot reference a certain status in my business logic. For example, how can I implement something like this? if (myObject.Status is Ready) do this else if (myObject.Status is Draft) do that... Since the statuses are loaded dynamically, I cannot tell for sure what particular Status object in the List represents the Draft or Ready status. Alternatively, I could just use an enumeration like public enum Statuses { Draft, Ready }; Then I could easily use an enumeration in my business logic. if (myObject.Status == Statuses.Draft) // do something... However, the problem with this approach is that every time the user wants to modify the list of Statuses (adding a new status, or renaming an existing status) the application has to be re-compiled. We cannot load the statuses dynamically from the database. Has anyone else come across a similar situation? Any solutions/patterns? Cheers, Mosh

  Read the article

• using xpath get the correct value in selectName

  - by Sangeeta

  Below I have written the code. I need help to get the right value in selectName. I am new to XPath. Basically with this code I am trying to achieve if employeeName = Chris I need to return 23549 to the calling function. Please help. Part of the code: public static string getEmployeeeID(string employeeName) { Cache cache = HttpContext.Current.Cache; string cacheNameEmployee = employeeName + "Tech"; if (cache[cacheNameEpm] == null) { XPathDocument doc = new XPathDocument(HttpContext.Current.Request.MapPath("inc/xml/" + SiteManager.Site.ToString() + "TechToolTip.xml")); XPathNavigator navigator = doc.CreateNavigator(); string selectName = "/Technologies/Technology[FieldName='" + fieldName + "']/EpmId"; XPathNodeIterator nodes = navigator.Select(selectName); if (nodes.Count > 0) { if (nodes.Current.Name.Equals("FieldName")) //nodes.Current.MoveToParent(); //nodes.Current.MoveToParent(); //nodes.Current.MoveToChild("//EpmId"); cache.Add(cacheNameEpm, nodes.Current.Value, null, DateTime.Now + new TimeSpan(4, 0, 0), System.Web.Caching.Cache.NoSlidingExpiration, CacheItemPriority.Default, null); } } return cache[cacheNameEpm] as string; } XML file <?xml version="1.0" encoding="utf-8" ?> <Employees> <Employee> <EName>Chris</EName> <ID>23556</ID> </Employee> <Employee> <EName>CBailey</EName> <ID>22222</ID> </Employee> <Employee> <EName>Meghan</EName> <ID>12345</ID> </Employee> </Employees> PLEASE NOTE:This XML file has 100 nodes. I just put 1 to indicate the structure.

  Read the article

• Class initialization and synchronized class method

  - by nybon

  Hi there, In my application, there is a class like below: public class Client { public synchronized static print() { System.out.println("hello"); } static { doSomething(); // which will take some time to complete } } This class will be used in a multi thread environment, many threads may call the Client.print() method simultaneously. I wonder if there is any chance that thread-1 triggers the class initialization, and before the class initialization complete, thread-2 enters into print method and print out the "hello" string? I see this behavior in a production system (64 bit JVM + Windows 2008R2), however, I cannot reproduce this behavior with a simple program in any environments. In Java language spec, section 12.4.1 (http://java.sun.com/docs/books/jls/second_edition/html/execution.doc.html), it says: A class or interface type T will be initialized immediately before the first occurrence of any one of the following: T is a class and an instance of T is created. T is a class and a static method declared by T is invoked. A static field declared by T is assigned. A static field declared by T is used and the reference to the field is not a compile-time constant (§15.28). References to compile-time constants must be resolved at compile time to a copy of the compile-time constant value, so uses of such a field never cause initialization. According to this paragraph, the class initialization will take place before the invocation of the static method, however, it is not clear if the class initialization need to be completed before the invocation of the static method. JVM should mandate the completion of class initialization before entering its static method according to my intuition, and some of my experiment supports my guess. However, I did see the opposite behavior in another environment. Can someone shed me some light on this? Any help is appreciated, thanks.

  Read the article

• Why do bind1st and bind2nd require constant function objects?

  - by rlbond

  So, I was writing a C++ program which would allow me to take control of the entire world. I was all done writing the final translation unit, but I got an error: error C3848: expression having type 'const `anonymous-namespace'::ElementAccumulator<T,BinaryFunction>' would lose some const-volatile qualifiers in order to call 'void `anonymous-namespace'::ElementAccumulator<T,BinaryFunction>::operator ()(const point::Point &,const int &)' with [ T=SideCounter, BinaryFunction=std::plus<int> ] c:\program files (x86)\microsoft visual studio 9.0\vc\include\functional(324) : while compiling class template member function 'void std::binder2nd<_Fn2>::operator ()(point::Point &) const' with [ _Fn2=`anonymous-namespace'::ElementAccumulator<SideCounter,std::plus<int>> ] c:\users\****\documents\visual studio 2008\projects\TAKE_OVER_THE_WORLD\grid_divider.cpp(361) : see reference to class template instantiation 'std::binder2nd<_Fn2>' being compiled with [ _Fn2=`anonymous-namespace'::ElementAccumulator<SideCounter,std::plus<int>> ] I looked in the specifications of binder2nd and there it was: it took a const AdaptibleBinaryFunction. So, not a big deal, I thought. I just used boost::bind instead, right? Wrong! Now my take-over-the-world program takes too long to compile (bind is used inside a template which is instantiated quite a lot)! At this rate, my nemesis is going to take over the world first! I can't let that happen -- he uses Java! So can someone tell me why this design decision was made? It seems like an odd decision. I guess I'll have to make some of the elements of my class mutable for now...

  Read the article

• How to retrieve the Description property from SettingsProperty?

  - by BadNinja

  For each item in my application's settings, I've added text to its Description Property which I want to retrieve at runtime. I'm sure I'm missing some basic logical nuance here, but everything I've tried has failed. Clearly, my understanding of what value needs to be passed to the Attributes property of the SettingsProperty class is wrong. I'm further confused by the fact that when I iterate through all they keys returned by SettingsProperty.Attributes.Keys, I can see "System.Configuration.SettingsDescriptionAttribute", but when I pass that string in as the key to the Attributes property, null is returned. Any insight into how to properly retrieve the value Description Property would be very much appreciated. Thanks. :) public void MyMethod() { SettingsPropertyCollection MyAppProperties = Properties.Settings.Default.Properties; IEnumerator enumerator = MyAppProperties.GetEnumerator(); // Iterate through all the keys to see what we have.... while (enumerator.MoveNext()) { SettingsProperty property = (SettingsProperty)enumerator.Current; ICollection myKeys = property.Attributes.Keys; foreach (object theKey in myKeys) System.Diagnostics.Debug.Print(theKey.ToString()); // One of the keys returned is: System.Configuration.SettingsDescriptionAttribute } enumerator.Reset(); while (enumerator.MoveNext()) { SettingsProperty property = (SettingsProperty)enumerator.Current; string propertyValue = property.DefaultValue.ToString(); // This fails: Null Reference string propertyDescription = property.Attributes["System.Configuration.SettingsDescriptionAttribute"].ToString(); // Do stuff with strings... } }

  Read the article

• Force a view change from a button when using UITabBarController

  - by user342197

  Hello - When using a UITabBarController, when the user enters some data on View1 and presses a button, I need to perform some calculations and present the results on View2. I have an AppDelegate, View1Controller, View2Controller, and View3Controller (View3 is a basically static view). My AppDelgate declares UITabBarController *rootController; On View1, I have the calculations being performed in an IBAction for buttonPressed; however, I can't seem to force the view to switch to View2 programmatically. I have done a lot of searching for similar problems, and think I should be doing something like "self.rootController.selectedIndex = 1"; however,when I do this from within buttonPressed on my View1Controller, I get an error "request for member rootController in something not in a structure or union". I think I'm missing something basic here... probably need do do something with my AppDelegate, but I'm banging my head against the wall. Can anyone provide some guidance in this situation...like key things I should do in View1Controller header and implementation with reference to my AppDelgate? Thank you!

  Read the article

• Python's asyncore to periodically send data using a variable timeout. Is there a better way?

  - by Nick Sonneveld

  I wanted to write a server that a client could connect to and receive periodic updates without having to poll. The problem I have experienced with asyncore is that if you do not return true when dispatcher.writable() is called, you have to wait until after the asyncore.loop has timed out (default is 30s). The two ways I have tried to work around this is 1) reduce timeout to a low value or 2) query connections for when they will next update and generate an adequate timeout value. However if you refer to 'Select Law' in 'man 2 select_tut', it states, "You should always try to use select() without a timeout." Is there a better way to do this? Twisted maybe? I wanted to try and avoid extra threads. I'll include the variable timeout example here: #!/usr/bin/python import time import socket import asyncore # in seconds UPDATE_PERIOD = 4.0 class Channel(asyncore.dispatcher): def __init__(self, sock, sck_map): asyncore.dispatcher.__init__(self, sock=sock, map=sck_map) self.last_update = 0.0 # should update immediately self.send_buf = '' self.recv_buf = '' def writable(self): return len(self.send_buf) > 0 def handle_write(self): nbytes = self.send(self.send_buf) self.send_buf = self.send_buf[nbytes:] def handle_read(self): print 'read' print 'recv:', self.recv(4096) def handle_close(self): print 'close' self.close() # added for variable timeout def update(self): if time.time() >= self.next_update(): self.send_buf += 'hello %f\n'%(time.time()) self.last_update = time.time() def next_update(self): return self.last_update + UPDATE_PERIOD class Server(asyncore.dispatcher): def __init__(self, port, sck_map): asyncore.dispatcher.__init__(self, map=sck_map) self.port = port self.sck_map = sck_map self.create_socket(socket.AF_INET, socket.SOCK_STREAM) self.bind( ("", port)) self.listen(16) print "listening on port", self.port def handle_accept(self): (conn, addr) = self.accept() Channel(sock=conn, sck_map=self.sck_map) # added for variable timeout def update(self): pass def next_update(self): return None sck_map = {} server = Server(9090, sck_map) while True: next_update = time.time() + 30.0 for c in sck_map.values(): c.update() # <-- fill write buffers n = c.next_update() #print 'n:',n if n is not None: next_update = min(next_update, n) _timeout = max(0.1, next_update - time.time()) asyncore.loop(timeout=_timeout, count=1, map=sck_map)

  Read the article

• Netlogo: error when putting variable in table, only constants allowe??

  - by Chantal

  Hello, Currently I am working on a Netlogo program where I need to use nodes and links for vehicle routing problem. (links are called streets in the program) Here I have some practical problems of how to input variable linkspeed in a table with another node. Constants like 200 etc are fine. Online I found some examples where variables are used, but I do not know why I keep getting the following error: Expected a constant. (or why netlogo expects a constant) Here is the relevant piece of code: extensions [table] streets-own [linkspeed linktoll] nodes-own [netw] ;; In another piece of code linkspeed is assigned successfully to the links to cheapcalc ;; start conditions set costs very high 300000 ;; state 3 unsearched state 2 searching state 1 searched (for later purposes) ask nodes [ set i 0 set j count nodes set netw table:make while [i < j][ table:put netw (i) [3000000 3] set i (i + 1)]] set i 0 let k 0 ask node 35 ;; here i use node 35 as an example. ;; node 35 is connected to node 34, 36, 20 and 50 [table:put netw (35) [0 1] ;; node need to search costs to travel to itself ;; putting constants is ok. while [i < j] [ask my-links [ask both-ends [if (who != 35) [set color blue ;; set temp ([linkspeed] of street 35 who) ;; here my real goal is to put this in stat of i. but i is easier than linkspeed. table:put netw (who) [ i 2 ] ] ] ] set i (i + 1)] ] ;; next node for later, no it is just repetition of the same. end I hope somebody knows what is going on... Kind regards, Chantal

  Read the article

• how to use a parameterized function for the Default Binding of a Sql Server column

  - by Walt Gaber

  I have a table that catalogs selected files from multiple sources. I want to record whether a file is a duplicate of a previously cataloged file at the time the new file is cataloged. I have a column in my table (“primary_duplicate”) to record each entry as ‘P’ (primary) or ‘D’ (duplicate). I would like to provide a Default Binding for this column that would check for other occurrences of this file (i.e. name, length, timestamp) at the time the new file is being recorded. I have created a function that performs this check (see “GetPrimaryDuplicate” below). But I don’t know how to bind this function which requires three parameters to the table’s “primary_duplicate” column as its Default Binding. I would like to avoid using a trigger. I currently have a stored procedure used to insert new records that performs this check. But I would like to ensure that the flag is set correctly if an insert is performed outside of this stored procedure. How can I call this function with values from the row that is being inserted? USE [MyDatabase] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TABLE [dbo].[FileCatalog]( [id] [uniqueidentifier] NOT NULL, [catalog_timestamp] [datetime] NOT NULL, [primary_duplicate] nchar NOT NULL, [name] nvarchar NULL, [length] [bigint] NULL, [timestamp] [datetime] NULL ) ON [PRIMARY] GO ALTER TABLE [dbo].[FileCatalog] ADD CONSTRAINT [DF_FileCatalog_id] DEFAULT (newid()) FOR [id] GO ALTER TABLE [dbo].[FileCatalog] ADD CONSTRAINT [DF_FileCatalog_catalog_timestamp] DEFAULT (getdate()) FOR [catalog_timestamp] GO ALTER TABLE [dbo].[FileCatalog] ADD CONSTRAINT [DF_FileCatalog_primary_duplicate] DEFAULT (N'GetPrimaryDuplicate(name, length, timestamp)') FOR [primary_duplicate] GO USE [MyDatabase] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE FUNCTION [dbo].[GetPrimaryDuplicate] ( @name nvarchar(255), @length bigint, @timestamp datetime ) RETURNS nchar(1) AS BEGIN DECLARE @c int SELECT @c = COUNT(*) FROM FileCatalog WHERE name=@name and length=@length and timestamp=@timestamp and primary_duplicate = 'P' IF @c > 0 RETURN 'D' -- Duplicate RETURN 'P' -- Primary END GO

  Read the article

• JUnit confusion: use 'extend Testcase' or '@Test' ?

  - by Rabarberski

  I've found the proper use (or at least the documentation) of JUnit very confusing. This question serves both as a future reference and as a real question. If I've understood correctly, there are two main approaches to create and run a JUnit test: Approach A: create a class that extends TestCase, and start test methods with the word test. When running the class as a JUnit Test (in Eclipse), all methods starting with the word test are automatically run. import junit.framework.TestCase; public class DummyTestA extends TestCase { public void testSum() { int a = 5; int b = 10; int result = a + b; assertEquals(15, result); } } Approach B: create a 'normal' class and prepend a @Test annotation to the method. Note that you do NOT have to start the method with the word test. import org.junit.*; import static org.junit.Assert.*; public class DummyTestB { @Test public void Sum() { int a = 5; int b = 10; int result = a + b; assertEquals(15, result); } } Mixing the two seems not to be a good idea, see e.g. this stackoverflow question: Now, my questions(s): What is the preferred approach, or when would you use one instead of the other? Approach B allows for testing for exceptions by extending the @Test annotation like in @Test(expected = ArithmeticException.class). But how do you test for exceptions when using approach A? When using approach A, you can group a number of test classes in a test suite. TestSuite suite = new TestSuite("All tests");<br/> suite.addTestSuite(DummyTestA.class); suite.addTestSuite(DummyTestAbis.class);` But this can't be used with approach B (since each testclass should subclass TestCase). What is the proper way to group tests for approach B?

  Read the article

• Error when linking C executable to OpenCV

  - by Ghilas BELHADJ

  I'm compiling OpenCV under Ubuntu 13.10 using cMake. i've already compiled c++ programs and they works well. now i'm trying to compile a C file using this cMakeLists.txt cmake_minimum_required (VERSION 2.8) project (hello) find_package (OpenCV REQUIRED) add_executable (hello src/test.c) target_link_libraries (hello ${OpenCV_LIBS}) here is the test.c file: #include <stdio.h> #include <stdlib.h> #include <opencv/highgui.h> int main (int argc, char* argv[]) { IplImage* img = NULL; const char* window_title = "Hello, OpenCV!"; if (argc < 2) { fprintf (stderr, "usage: %s IMAGE\n", argv[0]); return EXIT_FAILURE; } img = cvLoadImage(argv[1], CV_LOAD_IMAGE_UNCHANGED); if (img == NULL) { fprintf (stderr, "couldn't open image file: %s\n", argv[1]); return EXIT_FAILURE; } cvNamedWindow (window_title, CV_WINDOW_AUTOSIZE); cvShowImage (window_title, img); cvWaitKey(0); cvDestroyAllWindows(); cvReleaseImage(&img); return EXIT_SUCCESS; } it returns me this error whene running cmake . then make to the project: Linking C executable hello /usr/bin/ld: CMakeFiles/hello.dir/src/test.c.o: undefined reference to symbol «lrint@@GLIBC_2.1» /lib/i386-linux-gnu/libm.so.6: error adding symbols: DSO missing from command line collect2: error: ld returned 1 exit status make[2]: *** [hello] Erreur 1 make[1]: *** [CMakeFiles/hello.dir/all] Erreur 2 make: *** [all] Erreur 2

  Read the article

• File Enumeration with ANT

  - by 1ndivisible

  I feel like I'm missing something obvious at the moment. I want to collect a set of dirs / files together in ANT. I know I can do it using a fileset with an optional patternset inside it, but that involves searching for files based a specific criterior - filetype, name etc. I already know the paths to the files I want to collect. I have n properties which reference these paths. I want a way to collect these paths in a fileset, though I cannot find a way to do it. This represents what I want to achieve (I know it isn't valid code, but hopefully it will describe what I mean): <fileset> <path>${src.dir}</path> <path>${test.dir}</path> <path>${third.party.src.dir}</path> <path>${bin.dir}</path> <path>${docs.build.txt}</path> </fileset>

  Read the article

< Previous Page | 622 623 624 625 626 627 628 629 630 631 632 633  | Next Page >