Search Results

Search found 20211 results on 809 pages for 'language implementation'.

Page 697/809 | < Previous Page | 693 694 695 696 697 698 699 700 701 702 703 704  | Next Page >

  • Esper generating episodes

    - by Jasonojh
    I would like to use Esper to generate episodes of events. I am trying to detect the changes in robot movement during each time period and was wondering what would be the best way of implementation. The rules for generation of episodes from the events would be If the new event time(eg. 7sec, robot A) of a robot is more than 3 sec than the latest event(eg. 3 sec, robot A) of the same robot, the new event belongs to a new episode. Each episode should represent only one robot (eg. 2sec, robotA and 3sec, robotB should output 2 episodes) Input data: Event Time Robot Position 1 1 A 0 2 2 A 1 3 6 A 2 Output data should be: Array[0]={Event 1,Event 2} Array[1]={Event 3} //more than 3 sec Input data: Event Time Robot Position 1 1 A 0 2 2 A 1 3 4 B 0 4 6 A 2 Output data should be: Array[0]={Event 1,Event 2} Array[1]={Event 3} //different robot Array[2]={Event 4} Please help provide suggestions. I have tried using mulitple listeners, one for each robot, to create episodes and it works but I am trying to use a single EPL statement to do it. I have tried win:time_accum(3sec) group by robot but the second example output: Array[0]={Event 1,Event 2, Event 4} Array[1]={Event 3} as the time window is shifted everytime an event comes in, the system still thinks that event 4 is less than 3 sec due to event 3. how do I create a unique time window for each robot? Thank you for your suggestions and any help is greatly appreciated.

    Read the article

  • Purpose of singletons in programming

    - by thecoshman
    This is admittedly a rather loose question. My current understanding of singletons is that they are a class that you set up in such a way that only one instance is ever created. This sounds a lot like a static class to me. The main differnce being that with a static class you don't / can't instance it, you just use it such as Math.pi(). With a singletong class, you would still need to do something like singleton mySingleton = new singleton(); mysingleton.set_name("foo"); singleton otherSingleton = new singleton(); // correct me if i am wrong, but mysingleton == othersingleton right now, yes? // this the following should happen? otherSingleston.set_name("bar"); mysingleton.report_name(); // will output "bar" won't it? Please note, I am asking this language independently, more about the concept. So I am not so worried about actually how to coed such a class, but more why you would wan't to and what thing you would need to consider.

    Read the article

  • Listening UDP or switch to TCP in a MFC application

    - by Alexander.S
    I'm editing a legacy MFC application, and I have to add some basic network functionalities. The operating side has to receive a simple instruction (numbers 1,2,3,4...) and do something based on that. The clients wants the latency to be as fast as possible, so naturally I decided to use datagrams (UDP). But reading all sorts of resources left me bugged. I cannot listen to UDP sockets (CAsyncSocket) in MFC, it's only possible to call Receive which blocks and waits. Blocking the UI isn't really a smart. So I guess I could use some threading technique, but since I'm not all that experienced with MFC how should that be implemented? The other part of the question is should I do this, or revert to TCP, considering reliability and implementation issues. I know that UDP is unreliable, but just how unreliable is it really? I read that it is up to 50% faster, which is a lot for me. References I used: http://msdn.microsoft.com/en-us/library/09dd1ycd(v=vs.80).aspx

    Read the article

  • Send string from java (or other platform) to application

    - by MrSnowflake
    I want to send a barcode, read with my cellphone, to my computer. My computer has a simple server running, which listens to barcodes. When a barcode arrives, the server app should be able to input the value of the received barcode into the active application (I don't really care which application is going to get the input, the user should be able to select gedit, a terminal window or the browser if they choose to). My language at the moment is Java on GNU/Linux (Ubuntu), so I know about the Robot class. But the Robot class emulates a keyboard, which means: when you send VK_1 on a US keyboard layout, the output is '1' indeed, but when you send VK_1 on another layout (like belgian, which I use), which requires shift for the '1' key, the output is '&' (this is the character on the '1' key, when you don't hold shift). I also found xsendkeys, but this application too requires you to specify whether you need to hold shift. So it will be able to send an 'a' but for an 'A' (thus capital) you need to specify you want to hold shift with your 'a'. Isn't there an easy way to do this, for GNU/Linux and Windows, just using strings. I want to be able to send "12a68dd" to the active application. And I also would like to be able to send UTF-8 characters to the active application. I have been looking for a solution, but most require the breakdown in multiple keystrokes, which are often dependent on the keyboard layout.

    Read the article

  • R Tree 50,000 foot overview?

    - by roufamatic
    I'm working on a school project that involves taking a lat/long point and finding the top five closest points in a known list of places. The list is to be stored in memory, with the caveat that we must choose an "appropriate data structure" -- that is, we cannot simply store all the places in an array and compare distances one-by-one in a linear fashion. The teacher suggested grouping the place data by US State to prevent calculating the distance for places that are obviously too far away. I think I can do better. From my research online it seems like an R-Tree or one of its variants might be a neat solution. Unfortunately, that sentence is as far as I've gotten with understanding the actual technique, as the literature is simply too dense for my non-academic head. Can somebody give me a really high overview of what the process is for populating an R-Tree with lat/long data, and then traversing the tree to find those 5 nearest neighbors of a given point? Additionally the project is in C, and I don't have to reinvent the wheel on this, so if you've used an existing open source C implementation of an R Tree I'd be interested in your experiences.

    Read the article

  • fetching the label text from database in C#

    - by Yilmaz Paçariz
    private void button5_Click(object sender, EventArgs e) { SqlConnection conn = new SqlConnection("Data Source=MAZI-PC\\PROJECTACC;Initial Catalog=programDB;Integrated Security=True"); SqlCommand cmd = new SqlCommand("select label_sh from label_text where label_form='2' and label_form_labelID='1'", conn); conn.Open(); label1.Text = cmd.ExecuteReader().ToString(); conn.Close(); SqlConnection conn1 = new SqlConnection("Data Source=MAZI-PC\\PROJECTACC;Initial Catalog=programDB;Integrated Security=True"); SqlCommand cmd1 = new SqlCommand("select label_sh from label_text where label_form='2' and label_form_labelID='2'", conn1); conn1.Open(); label2.Text = cmd1.ExecuteReader().ToString(); conn1.Close(); SqlConnection conn2 = new SqlConnection("Data Source=MAZI-PC\\PROJECTACC;Initial Catalog=programDB;Integrated Security=True"); SqlCommand cmd2 = new SqlCommand("select label_sh from label_text where label_form='2' and label_form_labelID='3'", conn2); conn2.Open(); label3.Text = cmd2.ExecuteReader().ToString(); conn2.Close(); } I am developing a small project in C#... Using Visiual Studio 2010... I want to fetch the label texts from database in order to change the user interface language with a button... I wrote this code but there is a problem in SQLDATAREADER in label text parts it shows System.Data.SqlClient.SqlDataReader I cant fix, could you help me?

    Read the article

  • Adding new records in Access without wrecking the form

    - by Matt Parker
    I'm working on a simple Access 2003 application to keep track of things that need to be done for clients for some colleagues. Each colleague has a set of clients, and each client has a set of actions that need to be taken by a certain date. I've set up a form that consists of a combobox for client ID (indexed), a drop-down for the person who is handling that client's case, and a button for adding new clients (a standard Access-created Add Record button). The actions are listed in a subform below these three elements. The problem I've run into is that the first person I tested this on clicked the button to add a new record, then didn't fill it out and tried to select another client from the drop-down list. Access interprets this as an attempt to set the selected Client ID as the ID for the new record and rightfully throws an error for duplicate primary keys. I can think of a couple of ways around this problem, but I'd much rather hear your elegant solutions than kludge together some junk in a language I don't know. Let me know if you have any questions. Thank you.

    Read the article

  • Which is the event listener after doSave() in Symfony?

    - by fesja
    Hi, I've been looking at this event-listeners page http://www.doctrine-project.org/documentation/manual/1_1/pl/event-listeners and I'm not sure which is the listener I have to use to make a change after the doSave() method in the BaseModelForm.class.php. // PlaceForm.class.php protected function doSave ( $con = null ) { ... parent::doSave($con); .... // Only for new forms, insert place into the tree if($this->object->level == null){ $parent = Place::getPlace($this->getValue('parent'), Language::getLang()); ... $node = $this->object->getNode(); $method = ($node->isValidNode() ? 'move' : 'insert') . 'AsFirstChildOf'; $node->$method($parent); //calls $this->object->save internally } return; } What I want to do is to make a custom slug with the ancestors' name of that new place. So if I inserting "San Francisco", the slug would be "usa-california-san-francisco" public function postXXXXXX($event) { ... $event->getInvoker()->slug = $slug; } The problem is that I'm inserting a new object with no reference to its parent. After it's saved, I insert it to the tree. So I can't change the slug until then. I think a Transaction listener could work, but I'm use there is a better way I'm not seeing right now. thanks!

    Read the article

  • Using TXMLDocument to serialize form settings to XML and database.

    - by LukLed
    I have an interface: type IXMLSerializable = interface function SaveToXML : DOMString; function SaveToXMLDocument : IXMLDocument; procedure LoadFromXML(AXML : DOMString); end; It is used to serialize some settings of forms or frames to xml. Simple implementation: SaveToXMLDocument: function TSomething.SaveToXMLDocument: IXMLDocument; begin Result := TXMLDocument.Create(nil); with Result do begin Active := True; with AddChild(Self.Name) do begin AddChild(edSomeTextBox.Name).Attributes['Text'] := edSomeTextBox.Text; end; end; Result := XMLDoc; end; LoadFromXML: procedure TSomething.LoadFromXML(AXML: DOMString); var XMLDoc : IXMLDocument; I : Integer; begin XMLDoc := TXMLDocument.Create(nil); with XMLDoc do begin LoadFromXML(AXML); Active := True; with ChildNodes[0] do begin for I := 0 to ChildNodes.Count-1 do begin If ChildNodes[I].NodeName = 'edSomeTextBox' then edSomeTextBox.Text := ChildNodes[I].Attributes['Text']; end; end; end; end; SaveToXML: function TSomething.SaveToXML: DOMString; begin SaveToXMLDocument.SaveToXML(Result); end; DOMString result of SaveToXML is saved to database to blob field. I had some encoding issues with other implementations and this one works fine (right now). Do you see any dangers in this code? Can I have issues with different settings on various machines and systems?

    Read the article

  • How do I import facebook friends from another website

    - by Jim Zimmerman
    I am looking for a way to connect to facebook by allowing the user to enter in their username and password and have our app connect to their account and get their contacts so that they can invite them to join their group on our site. I have written a facebook app before, but this is not an app as much as it is a connector so that they can invite all their friends or just some to the site we are working on. I have seen several other sites do this and also connect to Yahoo, Gmail and Hotmail contacts. I dont think they are using Facebook Connect to do this since it is so new, but they may be. Any solution in any language is fine as I can port whatever example to use C#. I cannot find anything specifically on Google or Facebook to address this specific problem. Any help is appreciated. I saw a first answer get removed that had suggested i might need to scrape the friends page. The more I look around, this might be what i need to do. Any other way i think will require the person to add it as an app. I am wondering how a answer can get removed, maybe that user deleted it.

    Read the article

  • How can I make this simple C# generics factory work?

    - by Kevin Brassen
    I have this design: public interface IFactory<T> { T Create(); T CreateWithSensibleDefaults(); } public class AppleFactory : IFactory<Apple> { ... } public class BananaFactory : IFactory<Banana> { ... } // ... The fictitious Apple and Banana here do not necessarily share any common types (other than object, of course). I don't want clients to have to depend on specific factories, so instead, you can just ask a FactoryManager for a new type. It has a FactoryForType method: IFactory<T> FactoryForType<T>(); Now you can invoke the appropriate interface methods with something like FactoryForType<Apple>().Create(). So far, so good. But there's a problem at the implementation level: how do I store this mapping from types to IFactory<T>s? The naive answer is an IDictionary<Type, IFactory<T>>, but that doesn't work since there's no type covariance on the T (I'm using C# 3.5). Am I just stuck with an IDictionary<Type, object> and doing the casting manually?

    Read the article

  • Best (Java) book for understanding 'under the bonnet' for programming?

    - by Ben
    What would you say is the best book to buy to understand exactly how programming works under the hood in order to increase performance? I've coded in assembly at university, I studied computer architecture and I obviously did high level programming, but what I really dont understand is things like: -what is happening when I perform a cast -whats the difference in performance if I declare something global as opposed to local? -How does the memory layout for an ArrayList compare with a Vector or LinkedList? -Whats the overhead with pointers? -Are locks more efficient than using synchronized? -Would creating my own array using int[] be faster than using ArrayList -Advantages/disadvantages of declaring a variable volatile I have got a copy of Java Performance Tuning but it doesnt go down very low and it contains rather obvious things like suggesting a hashmap instead of using an ArrayList as you can map the keys to memory addresses etc. I want something a bit more Computer Sciencey, linking the programming language to what happens with the assembler/hardware. The reason im asking is that I have an interview coming up for a job in High Frequency Trading and everything has to be as efficient as possible, yet I cant remember every single possible efficiency saving so i'd just like to learn the fundamentals. Thanks in advance

    Read the article

  • Objective C: Function returning correct data for the first time of call and null for other times

    - by Kooshal Bhungy
    Hi all, Am a beginner in objective C, i am implementing a function that would query a web server and display the returning string in console. I am calling the function (getDatafromServer) repeatedly in a loop. The problem is that the first time am getting the value whereas the other times, it returns me a (null) in console... I've searched about memory management and check out on the forums but none have worked. Can you please guys tell me where am wrong in the codes below? Thanks in advance.... @implementation RequestThread +(void)startthread:(id)param{ while (true) { //NSLog(@"Test threads"); sleep(5); NSLog(@"%@",[self getDatafromServer]); } } +(NSString *) getDatafromServer{ NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; NSString *myRequestString = @"name=Hello%20&[email protected]"; NSData *myRequestData = [NSData dataWithBytes:[myRequestString UTF8String] length:[myRequestString length]]; NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL: [NSURL URLWithString:@"http://192.168.1.32/gs/includes/widget/getcalls.php?user=asdasd&passw=asdasdasd"]]; [request setHTTPMethod:@"POST"]; [request setHTTPBody: myRequestData]; [request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"content-type"]; NSData *returnData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil]; NSString *myString = [NSString stringWithUTF8String:[returnData bytes]]; [myRequestString release]; [request release]; [returnData release]; return myString; [pool release]; } @end

    Read the article

  • How can I implement a splay tree that performs the zig operation last, not first?

    - by Jakob
    For my Algorithms & Data Structures class, I've been tasked with implementing a splay tree in Haskell. My algorithm for the splay operation is as follows: If the node to be splayed is the root, the unaltered tree is returned. If the node to be splayed is one level from the root, a zig operation is performed and the resulting tree is returned. If the node to be splayed is two or more levels from the root, a zig-zig or zig-zag operation is performed on the result of splaying the subtree starting at that node, and the resulting tree is returned. This is valid according to my teacher. However, the Wikipedia description of a splay tree says the zig step "will be done only as the last step in a splay operation" whereas in my algorithm it is the first step in a splay operation. I want to implement a splay tree that performs the zig operation last instead of first, but I'm not sure how it would best be done. It seems to me that such an algorithm would become more complex, seeing as how one needs to find the node to be splayed before it can be determined whether a zig operation should be performed or not. How can I implement this in Haskell (or some other functional language)?

    Read the article

  • dynamically insert new rows in the table (JavaScript) ?

    - by Karandeep Singh
    <script type="text/javascript" language="javascript"> function addNewRow() { var table = document.getElementById("table1"); var tr = table.insertRow(); var td = tr.insertCell(); td.innerHTML= "a"; td = tr.insertCell(); td.innerHTML= "b"; td = tr.insertCell(); td.innerHTML= "c"; td = tr.insertCell(); td.innerHTML= "d"; td = tr.insertCell(); td.innerHTML= "e"; } </script> <body> <table id="table1" border="1" cellpadding="0" cellspacing="0" width="100%"> <tr id="row1"> <td>1</td> <td>2</td> <td>3</td> <td>4</td> <td>5</td> </tr> </table> <input type="button" onClick="addNewRow()" value="Add New"/> </body> This example is for dynamically insert new row and cells in the table. But its behavior is different in all browsers. Internet Explorer = It add row in the last and new added cells are starts from first. Chrome/Safari = It add new row in the first and new added cells are starts from end. Mozilla Firefox = It is not working. Sir, I want new added row in the last and new added cells starts from first like(Interner Explorer) in all browsers. If you have any solution for same behavior please tell me. Thanks,

    Read the article

  • C++ private inheritance and static members/types

    - by WearyMonkey
    I am trying to stop a class from being able to convert its 'this' pointer into a pointer of one of its interfaces. I do this by using private inheritance via a middle proxy class. The problem is that I find private inheritance makes all public static members and types of the base class inaccessible to all classes under the inheriting class in the hierarchy. class Base { public: enum Enum { value }; }; class Middle : private Base { }; class Child : public Middle { public: void Method() { Base::Enum e = Base::value; // doesn't compile BAD! Base* base = this; // doesn't compile GOOD! } }; I've tried this in both VS2008 (the required version) and VS2010, neither work. Can anyone think of a workaround? Or a different approach to stopping the conversion? Also I am curios of the behavior, is it just a side effect of the compiler implementation, or is it by design? If by design, then why? I always thought of private inheritance to mean that nobody knows Middle inherits from Base. However, the exhibited behavior implies private inheritance means a lot more than that, in-fact Child has less access to Base than any namespace not in the class hierarchy!

    Read the article

  • trying to reenter IT field after a break of over 5 years

    - by josephj1989
    Hello I have had some misfortune in life - I was unwell and had to stay out of work for an extended period of about 5 years.Before that I used to work as an Oracle/Oracle Ebusiness suite consultant (I was charging very good contract rates). But now I am fully recovered ,feeling sharper than ever. But there arent many opportunities in my areas of expertise in a small market like New Zealand and the long absence is no help either. So for the last 5 months I have been training myself in C# ,ASP .NET,WEB technologies like HTML,JQuery,CSS and also SQL Server.I had some previous experience with JAVA and VB .NET (few months). But I am fully confident of my abilities and believe I can hit the ground running given a chance.I used to be an expert with SQL and C language and these skills are portable to SQL Server and C#. Another problem I face is my age- I am over 50. What is your opinion - Am I doing the right thing. Can I get back into an IT career-I am willing to start all over again at a junior level, I am really facing a crisis in my life.

    Read the article

  • How to convert X/Y position to Canvas Left/Top properties when using ItemsControl

    - by kshahar
    I am trying to use a Canvas to display objects that have "world" location (rather than "screen" location). The canvas is defined like this: <Canvas Background="AliceBlue"> <ItemsControl Name="myItemsControl" ItemsSource="{Binding MyItems}"> <ItemsControl.ItemTemplate> <DataTemplate> <Canvas> <TextBlock Canvas.Left="{Binding WorldX}" Canvas.Top="{Binding WorldY}" Text="{Binding Text}" Width="Auto" Height="Auto" Foreground="Red" /> </Canvas> </DataTemplate> </ItemsControl.ItemTemplate> </ItemsControl> </Canvas> MyItem is defined like this: public class MyItem { public MyItem(double worldX, double worldY, string text) { WorldX = worldX; WorldY = worldY; Text = text; } public double WorldX { get; set; } public double WorldY { get; set; } public string Text { get; set; } } In addition, I have a method to convert between world and screen coordinates: Point worldToScreen(double worldX, double worldY) { // return screen coordinates using the canvas properties and an internal MapData object } With the current implementation, the items are positioned in the wrong location, because their location is not converted to screen coordinates. How can I apply the worldToScreen method on the MyItem objects before they are added to the canvas?

    Read the article

  • Problem FlashVars parameter asp.net

    - by sofie-vo
    Code for asp.net page <%@ Page Language="VB" AutoEventWireup="false" CodeFile="trainingupload.aspx.vb" Inherits="trainingupload" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title></title> </head> <body> <form id="form1" runat="server"> <div height> <object width="1000" height="800"> <param name="movie" value="player.swf" /> <param name="FlashVars" value='userid=<%=String.Format(getuser())%>" '/> <embed src="bin-release/trainingscentrum.swf" FlashVars='userid=<%=String.Format(getuser())%>" ' width="1500" height="800" /> </embed> </object> </div> </form> </body> </html> Code behind Public Function getuser() As Guid Dim user As MembershipUser = Membership.GetUser() Dim userid As Guid = (CType(user.ProviderUserKey, Guid)) Return userid End Function In the code above I use an function to return the userid. When I replace <%=String.Format(getuser())% with an actual userid, I get the value in my flex application. But this code returns nothing. What am I doing wrong?

    Read the article

  • Strange thread behavior in Perl

    - by Zaid
    Tom Christiansen's example code (à la perlthrtut) is a recursive, threaded implementation of finding and printing all prime numbers between 3 and 1000. Below is a mildly adapted version of the script #!/usr/bin/perl # adapted from prime-pthread, courtesy of Tom Christiansen use strict; use warnings; use threads; use Thread::Queue; sub check_prime { my ($upstream,$cur_prime) = @_; my $child; my $downstream = Thread::Queue->new; while (my $num = $upstream->dequeue) { next unless ($num % $cur_prime); if ($child) { $downstream->enqueue($num); } else { $child = threads->create(\&check_prime, $downstream, $num); if ($child) { print "This is thread ",$child->tid,". Found prime: $num\n"; } else { warn "Sorry. Ran out of threads.\n"; last; } } } if ($child) { $downstream->enqueue(undef); $child->join; } } my $stream = Thread::Queue->new(3..shift,undef); check_prime($stream,2); When run on my machine (under ActiveState & Win32), the code was capable of spawning only 118 threads (last prime number found: 653) before terminating with a 'Sorry. Ran out of threads' warning. In trying to figure out why I was limited to the number of threads I could create, I replaced the use threads; line with use threads (stack_size => 1);. The resultant code happily dealt with churning out 2000+ threads. Can anyone explain this behavior?

    Read the article

  • crash when using stl vector at instead of operator[]

    - by Jamie Cook
    I have a method as follows (from a class than implements TBB task interface - not currently multithreading though) My problem is that two ways of accessing a vector are causing quite different behaviour - one works and the other causes the entire program to bomb out quite spectacularly (this is a plugin and normally a crash will be caught by the host - but this one takes out the host program as well! As I said quite spectacular) void PtBranchAndBoundIterationOriginRunner::runOrigin(int origin, int time) const // NOTE: const method { BOOST_FOREACH(int accessMode, m_props->GetAccessModes()) { // get a const reference to appropriate vector from member variable // map<int, vector<double>> m_rowTotalsByAccessMode; const vector<double>& rowTotalsForAccessMode = m_rowTotalsByAccessMode.find(accessMode)->second; if (origin != 129) continue; // Additional debug constrain: I know that the vector only has one non-zero element at index 129 m_job->Write("size: " + ToString(rowTotalsForAccessMode.size())); try { // check for early return... i.e. nothing to do for this origin if (!rowTotalsForAccessMode[origin]) continue; // <- this works if (!rowTotalsForAccessMode.at(origin)) continue; // <- this crashes } catch (...) { m_job->Write("Caught an exception"); // but its not an exception } // do some other stuff } } I hate not putting in well defined questions but at the moment my best phrasing is : "WTF?" I'm compiling this with Intel C++ 11.0.074 [IA-32] using Microsoft (R) Visual Studio Version 9.0.21022.8 and my implementation of vector has const_reference operator[](size_type _Pos) const { // subscript nonmutable sequence #if _HAS_ITERATOR_DEBUGGING if (size() <= _Pos) { _DEBUG_ERROR("vector subscript out of range"); _SCL_SECURE_OUT_OF_RANGE; } #endif /* _HAS_ITERATOR_DEBUGGING */ _SCL_SECURE_VALIDATE_RANGE(_Pos < size()); return (*(_Myfirst + _Pos)); } (Iterator debugging is off - I'm pretty sure) and const_reference at(size_type _Pos) const { // subscript nonmutable sequence with checking if (size() <= _Pos) _Xran(); return (*(begin() + _Pos)); } So the only difference I can see is that at calls begin instead of simply using _Myfirst - but how could that possibly be causing such a huge difference in behaviour?

    Read the article

  • Python lists/arrays: disable negative indexing wrap-around

    - by wim
    While I find the negative number wraparound (i.e. A[-2] indexing the second-to-last element) extremely useful in many cases, there are often use cases I come across where it is more of an annoyance than helpful, and I find myself wishing for an alternate syntax to use when I would rather disable that particular behaviour. Here is a canned 2D example below, but I have had the same peeve a few times with other data structures and in other numbers of dimensions. import numpy as np A = np.random.randint(0, 2, (5, 10)) def foo(i, j, r=2): '''sum of neighbours within r steps of A[i,j]''' return A[i-r:i+r+1, j-r:j+r+1].sum() In the slice above I would rather that any negative number to the slice would be treated the same as None is, rather than wrapping to the other end of the array. Because of the wrapping, the otherwise nice implementation above gives incorrect results at boundary conditions and requires some sort of patch like: def ugly_foo(i, j, r=2): def thing(n): return None if n < 0 else n return A[thing(i-r):i+r+1, thing(j-r):j+r+1].sum() I have also tried zero-padding the array or list, but it is still inelegant (requires adjusting the lookup locations indices accordingly) and inefficient (requires copying the array). Am I missing some standard trick or elegant solution for slicing like this? I noticed that python and numpy already handle the case where you specify too large a number nicely - that is, if the index is greater than the shape of the array it behaves the same as if it were None.

    Read the article

  • Error in bisection method code in Matlab

    - by Amanda Collins
    I need to write a proper implementation of the bisection method, which means I must address all possible user input errors. Here is my code: function [x_sol, f_at_x_sol, N_iterations] = bisection(f, xn, xp, eps_f, eps_x) % solving f(x)=0 with bisection method % f is the function handle to the desired function, % xn and xp are borders of search, % f(xn)<0 and f(xp)>0 required, % eps_f defines how close f(x) should be to zero, % eps_x defines uncertainty of solution x if(f(xp) < 0) error('xp must be positive') end; if(f(xn)>0) error('xn must be negative') end; if (xn >= xp) error ('xn must be less than xp') end; xg=(xp+xn)/2; %initial guess fg=f(xg); % initial function evaluation N_iterations=1; while ( (abs(fg) > eps_f) & (abs(xg-xp) > eps_x) ) if (fg>0) xp=xg; else xn=xg; end xg=(xp+xn)/2; %update guess fg=f(xg); %update function evaluation N_iterations=N_iterations+1; end x_sol=xg; %solution is ready f_at_x_sol=fg; if (f_at_x_sol > eps_f) error('No convergence') end and here is the error message I receive when I try to test this in Matlab: >> bisection(x.^2, 2, -1, 1e-8, 1e-10) Attempted to access f(-1); index must be a positive integer or logical. Error in bisection (line 9) if(f(xp)<0) I was attempting to see if my error codes worked, but it doesn't look like they do. I get the same error when I try to test it on a function that should work.

    Read the article

  • Transparently surround a component with a link in Wicket

    - by Toni Menzel
    I want to be able to add links on certain items in an ListView. If an items is surrounded by the link or not is up to the code, so its not in the normal page markup. Say i have a markup like this: <div class="column" wicket:id="columnRepeater"> <span wicket:id="column"></span> </div> So essentially, while filling the repeater with a ListView i am able to find a custom renderer for the column component. (not my playingfield). What i want is to add a Link/Ajax Link around the column component. I learned using wicket:border lets you surround additional stuff. Now, the border markup looks like this: <wicket:border> <a wicket:id="link"><wicket:body/></a> </wicket:border> Now, i am a bit puzzled what the Border implementation looks like. Anyone there who can suggest a working java part? I have a couple of "work in progress" solutions but none works. Most questions have to do with usage of component ids. Is the border id = column ? Whats the id of the inner (border body) id then?

    Read the article

  • How to resize a UISwitch?

    - by mshsayem
    I have made a custom UISwitch (from this post). But the problem is, my custom texts are a bit long. Is there any way to resize the switch? [I tried setBounds, did not work] Edit: Here is the code I used: @interface CustomUISwitch : UISwitch - (void) setLeftLabelText: (NSString *) labelText; - (void) setRightLabelText: (NSString *) labelText; @end @implementation CustomUISwitch - (UIView *) slider { return [[self subviews] lastObject]; } - (UIView *) textHolder { return [[[self slider] subviews] objectAtIndex:2]; } - (UILabel *) leftLabel { return [[[self textHolder] subviews] objectAtIndex:0]; } - (UILabel *) rightLabel { return [[[self textHolder] subviews] objectAtIndex:1]; } - (void) setLeftLabelText: (NSString *) labelText { [[self leftLabel] setText:labelText]; } - (void) setRightLabelText: (NSString *) labelText { [[self rightLabel] setText:labelText]; } @end mySwitch = [[CustomUISwitch alloc] initWithFrame:CGRectZero]; //Tried these, but did not work //CGRect aFrame = mySwitch.frame; //aFrame.size.width = 200; //aFrame.size.height = 100; //mySwitch.frame = aFrame; [mySwitch setLeftLabelText: @"longValue1"]; [mySwitch setRightLabelText: @"longValue2"];

    Read the article

< Previous Page | 693 694 695 696 697 698 699 700 701 702 703 704  | Next Page >