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  • Parallel.For Batching

    - by chibacity
    Is there built-in support in the TPL for batching operations? I was recently playing with a routine to carry out character replacement on a character array which required a lookup table i.e. transliteration: for (int i = 0; i < chars.Length; i++) { char replaceChar; if (lookup.TryGetValue(chars[i], out replaceChar)) { chars[i] = replaceChar; } } I could see that this could be trivially parallelized, so jumped in with a first stab which I knew would perform worse as the tasks were too fine-grained: Parallel.For(0, chars.Length, i => { char replaceChar; if (lookup.TryGetValue(chars[i], out replaceChar)) { chars[i] = replaceChar; } }); I then reworked the algorithm to use batching so that the work could be chunked onto different threads in less fine-grained batches. This made use of threads as expected and I got some near linear speed up. I'm sure that there must be built-in support for batching in the TPL. What is the syntax, and how do I use it? const int CharBatch = 100; int charLen = chars.Length; Parallel.For(0, ((charLen / CharBatch) + 1), i => { int batchUpper = ((i + 1) * CharBatch); for (int j = i * CharBatch; j < batchUpper && j < charLen; j++) { char replaceChar; if (lookup.TryGetValue(chars[j], out replaceChar)) { chars[j] = replaceChar; } } });

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  • WPF and LINQ/SQL - how and where to keep track of changes?

    - by Groky
    I have a WPF application built using the MVVM pattern: My Models come from LINQ to SQL. I use the Repository Pattern to abstract away the DataContext. My ViewModels have a reference to a Model. Setting a property on the ViewModel causes that value to be written through to the Model. As you can see, my data is stored in my Model, and changes are therefore tracked by my DataContext. However, in this question I read: The guidelines from the MSDN documentation on the DataContext class are what I would recommend following: In general, a DataContext instance is designed to last for one "unit of work" however your application defines that term. A DataContext is lightweight and is not expensive to create. A typical LINQ to SQL application creates DataContext instances at method scope or as a member of short-lived classes that represent a logical set of related database operations. How do you track your changes? In your DataContext? In your ViewModel? Elsewhere?

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  • Use properties or methods to expose business rules in C#?

    - by Val
    I'm writing a class to encapsulate some business rules, each of which is represented by a boolean value. The class will be used in processing an InfoPath form, so the rules get the current program state by looking up values in a global XML data structure using XPath operations. What's the best (most idiomatic) way to expose these rules to callers -- properties or public methods? Call using properties Rules rules = new Rules(); if ( rules.ProjectRequiresApproval ) { // get approval } else { // skip approval } Call using methods Rules rules = new Rules(); if ( rules.ProjectRequiresApproval() ) { // get approval } else { // skip approval } Rules class exposing rules as properties public class Rules() { private int _amount; private int threshold = 100; public Rules() { _amount = someExpensiveXpathOperation; } // rule property public bool ProjectRequiresApproval { get { return _amount < threshold } } } Rules class exposing rules as methods public class Rules() { private int _amount; private int threshold = 100; public Rules() { _amount = someExpensiveXpathOperation; } // rule method public bool ProjectRequiresApproval() { return _amount < threshold; } } What are the pros and cons of one over the other?

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  • Is it possible to create an Android Service that listens for hardware key presses?

    - by VoteBrian
    I'd like to run an Android background service that will act as a keylistener from the home screen or when the phone is asleep. Is this possible? From semi-related examples online, I put together the following service, but get the error, "onKeyDown is undefined for the type Service". Does this mean it can't be done without rewriting Launcher, or is there something obvious I'm missing? public class ServiceName extends Service { @Override public void onCreate() { //Stuff } public IBinder onBind(Intent intent) { //Stuff return null; } @Override public boolean onKeyDown(int keyCode, KeyEvent event) { if(event.getAction() == KeyEvent.ACTION_DOWN) { switch(keyCode) { case KeyEvent.KEYCODE_A: //Stuff return true; case KeyEvent.KEYCODE_B: //Stuff return true; //etc. } } return super.onKeyDown(keyCode, event); } } I realize Android defaults to the search bar when you type from the home screen, but this really is just for a very particular use. I don't really expect anyone but me to want this. I just think it'd be nice, for example, to use the camera button to wake the phone.

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  • How can I intercept an exception occurred during serialization in WCF?

    - by bonomo
    I have a legit data object with all data contract / data member attributes. For some reason the WCF service crashes after the operation has completed and the result is passed as a return value. I believe it has something to do with WCF not being able to serialize that result properly. The test client doesn't say anything specific: The underlying connection was closed: The connection was closed unexpectedly. Server stack trace: at System.ServiceModel.Channels.HttpChannelUtilities.ProcessGetResponseWebException(WebException webException, HttpWebRequest request, HttpAbortReason abortReason) at System.ServiceModel.Channels.HttpChannelFactory.HttpRequestChannel.HttpChannelRequest.WaitForReply(TimeSpan timeout) at System.ServiceModel.Channels.RequestChannel.Request(Message message, TimeSpan timeout) at System.ServiceModel.Dispatcher.RequestChannelBinder.Request(Message message, TimeSpan timeout) at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout) at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation) at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message) Exception rethrown at [0]: at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg) at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type) at IFacade.PickSecurities(String pattern, Int32 atMost) at FacadeClient.PickSecurities(String pattern, Int32 atMost) Inner Exception: The underlying connection was closed: The connection was closed unexpectedly. at System.Net.HttpWebRequest.GetResponse() at System.ServiceModel.Channels.HttpChannelFactory.HttpRequestChannel.HttpChannelRequest.WaitForReply(TimeSpan timeout) I am in control of creating the instance of the service using a customized service host factory. I know I can set up trace listeners and check the logs, but it's a lot of hassle to do. So I would rather handle it explicitly on the server at the time it happens. So I how can I intercept that exception programmatically and return an appropriate fault meassage?

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  • Implementing Dispose on a class derived from Stream

    - by AnthonyWJones
    I'm building a class that derives from Stream to wrap a COM IStream. However I've come across an issue where I need to release the COM IStream deteministically. Ok so that's easy just use Marshal.ReleaseComObject in the Dispose method. However I'm not sure its that simple. The Stream base class already has an protected virtual method Dispose(boolean). Here is my first idea:- ~ComStreamWrapper() { if (!_Disposed) { iop.Marshal.FreeCoTaskMem(_Int64Ptr); iop.Marshal.ReleaseComObject(_IStream); } } protected override void Dispose(bool disposing) { base.Dispose(disposing); if (!_Disposed) { if (disposing) { iop.Marshal.FreeCoTaskMem(_Int64Ptr); iop.Marshal.ReleaseComObject(_IStream); } _Disposed = true; } } You'll notice there isn't an implementation of Dispose() itself. I'm currently making the asssumption that the existing implementation on Stream does what I need it to. That is calling Diposing(true) and GC.SuppressFinalize. Is this assumption faulty? Have I missed something? Is there a better approach? You see more of the basic class in this answer to an ealier question.

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  • Problem in getting response from server in jquery

    - by Alvin
    Hello, I'm using $.ajax(options) method to pass the request to server based on username and password, but whenever I try to print the response by XMLHttpRequest object when response gets successful, I'm getting an empty value. $(document).ready(function(){ $("#form").submit(function(){ $.ajax({url:"Chat.jsp",type:"POST",data:$("#form").serialize(),success:function(request) { alert(request.responseText); //This is displaying nothing },error:function(){document.write("YOU can't");}}); }); }); This is what I'm doing in my servlets code after executing query: try { String user = request.getParameter("j_username"); String password = request.getParameter("j_password"); if(user != null && password != null) { String query = "Select * from users where user_name="+"\'"+user+"\'"+"&& user_pass="+"\""+password+"\""; DBCheck db= new DBCheck(); boolean b = db.doExecuteQuery(con.createStatement(),query); response.setHeader("Cache-Control", "no-cache"); if(b) { response.getWriter().println("Username already exits"); } else { response.getWriter().println("Username doesn't exit"); } } } catch(SQLException ex) { ex.printStackTrace(); } } May I know the problem, and how can I fix it?

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  • Model class for NSDictionary information with Lazy Loading

    - by samfu_1
    My application utilizes approx. 50+ .plists that are used as NSDictionaries. Several of my view controllers need access to the properties of the dictionaries, so instead of writing duplicate code to retrieve the .plist, convert the values to a dictionary, etc, each time I need the info, I thought a model class to hold the data and supply information would be appropriate. The application isn't very large, but it does handle a good deal of data. I'm not as skilled in writing model classes that conform to the MVC paradigm, and I'm looking for some strategies for this implementation that also supports lazy loading.. This model class should serve to supply data to any view controller that needs it and perform operations on the data (such as adding entries to dictionaries) when requested by the controller functions currently planned: returning the count on any dictionary adding one or more dictionaries together Currently, I have this method for supporting the count lookup for any dictionary. Would this be an example of lazy loading? -(NSInteger)countForDictionary: (NSString *)nameOfDictionary { NSBundle *bundle = [NSBundle mainBundle]; NSString *plistPath = [bundle pathForResource: nameOfDictionary ofType: @"plist"]; //load plist into dictionary NSMutableDictionary *dictionary = [[NSMutableDictionary alloc] initWithContentsOfFile: plistPath]; NSInteger count = [dictionary count] [dictionary release]; [return count] }

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  • why toString method does not work here??

    - by user329820
    Hi this is my whole class ,I have added number 2 to the doubly linked list and then I want it to be be print in the concole but it will show this "datastructureproject.Node@f62373" thanks! package datastructureproject; public class DoublyLinkedList { private Node head = new Node(0); private Node tail = new Node(0); private int length = 0; public DoublyLinkedList() { head.setPrev(null); head.setNext(tail); tail.setPrev(head); tail.setNext(null); } public void add(int index, int value) throws IndexOutOfBoundsException { Node cursor = get(index); Node temp = new Node(value); temp.setPrev(cursor); temp.setNext(cursor.getNext()); cursor.getNext().setPrev(temp); cursor.setNext(temp); length++; } private Node get(int index) throws IndexOutOfBoundsException { if (index < 0 || index > length) { throw new IndexOutOfBoundsException(); } else { Node cursor = head; for (int i = 0; i < index; i++) { cursor = cursor.getNext(); } return cursor; } } public long size() { return length; } public boolean isEmpty() { return length == 0; } @Override public String toString() { StringBuffer result = new StringBuffer(); result.append("(head) - "); Node temp = head; while (temp.getNext() != tail) { temp = temp.getNext(); result.append(temp.getValue() + " - "); } result.append("(tail)"); return result.toString(); } public static void main(String[] args){ DoublyLinkedList list = new DoublyLinkedList(); list.add(0,2 ); System.out.println(list.get(0).toString()); } }

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  • Read Cookies using Javascript

    - by Ajith
    I want to create a cookie using php,an also i need to read it using javascript.ie, by using setcookie('mycookie','hello',time()+34000) in php i am creating a cookie in my system.Now,i need to read it using javascript.Is it possible?If anybody knows please give me some idea.Please....help me.I am using javscript as follows ` function Get_Cookie( check_name ) { // first we'll split this cookie up into name/value pairs // note: document.cookie only returns name=value, not the other components var a_all_cookies = document.cookie.split( ';' ); var a_temp_cookie = ''; var cookie_name = ''; var cookie_value = ''; var b_cookie_found = false; // set boolean t/f default f for ( i = 0; i < a_all_cookies.length; i++ ) { // now we'll split apart each name=value pair a_temp_cookie = a_all_cookies[i].split( '=' ); // and trim left/right whitespace while we're at it cookie_name = a_temp_cookie[0].replace(/^\s+|\s+$/g, ''); // if the extracted name matches passed check_name if ( cookie_name == check_name ) { b_cookie_found = true; // we need to handle case where cookie has no value but exists (no = sign, that is): if ( a_temp_cookie.length > 1 ) { cookie_value = unescape( a_temp_cookie[1].replace(/^\s+|\s+$/g, '') ); } // note that in cases where cookie is initialized but no value, null is returned return cookie_value; break; } a_temp_cookie = null; cookie_name = ''; } if ( !b_cookie_found ) { return null; } } if (Get_Cookie('__gsb')) { alert('Found'); } `

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  • Altering ManagedObjects In NSArray

    - by Garry
    I have an entity called 'Job' with two boolean attributes named 'completed' and 'logged'. I am trying to retrieve all completed jobs that have not been logged at app start-up and change them to logged. I'm able to get all the completed but unlogged jobs with this fetchRequest: NSPredicate *predicate = [NSPredicate predicateWithFormat:@"(completed == %@ && logged == %@)", [NSNumber numberWithBool:YES], [NSNumber numberWithBool:NO]]; I'm then assigning this predicate to a fetchRequest and calling the [managedObjectContext executeFetchRequest:fetchRequest] method to get an array of all Job entities that meet this criteria. This seems to work fine and is returning the correct number of jobs. What I've been trying to do is loop through the NSArray returned, set the logged attribute to YES and then save. This seems to complete and doesn't return any errors but the changes are not persisted when the application quits. Where am I going wrong? [fetchRequest setPredicate:predicate]; NSError error; NSArray jobsToLog = [managedObjectContext executeFetchRequest:fetchRequest error:&error]; if ([jobsToLog count] > 0) { for (int i = 0; i < [jobsToLog count] - 1; i++) { [[jobsToLog objectAtIndex:i] setLogged:[NSNumber numberWithBool:YES]]; // Commit the changes made to disk error = nil; if (![managedObjectContext save:&error]) { // An error occurred } } } Thanks in anticipation,

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  • Creating a new object destroys an older object with different name in C++

    - by Mikael
    First question here! So, I am having some problems with pointers in Visual C++ 2008. I'm writing a program which will control six cameras and do some processing on them so to clean things up I have created a Camera Manager class. This class handles all operations which will be carried out on all the cameras. Below this is a Camera class which interacts with each individual camera driver and does some basic image processing. Now, the idea is that when the manager is initialised it creates two cameras and adds them to a vector so that I can access them later. The catch here is that when I create the second camera (camera2) the first camera's destructor is called for some reason, which then disconnects the camera. Normally I'd assume that the problem is somewhere in the Camera class, but in this case everything works perfectly as long as I don't create the camera2 object. What's gone wrong? CameraManager.h: #include "stdafx.h" #include <vector> #include "Camera.h" class CameraManager{ std::vector<Camera> cameras; public: CameraManager(); ~CameraManager(); void CaptureAll(); void ShowAll(); }; CameraManager.cpp: #include "stdafx.h" #include "CameraManager.h" CameraManager::CameraManager() { printf("Camera Manager: Initializing\n"); [...] Camera *camera1 = new Camera(NodeInfo,1, -44,0,0); cameras.push_back(*camera1); // Adding the following two lines causes camera1's destructor to be called. Why? Camera *camera2 = new Camera(NodeInfo,0, 44,0,0); cameras.push_back(*camera2); printf("Camera Manager: Ready\n"); }

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  • static variable lose its value

    - by user542719
    I have helper class with this static variable that is used for passing data between two classes. public class Helper{ public static String paramDriveMod;//this is the static variable in first calss } this variable is used in following second class mathod public void USB_HandleMessage(char []USB_RXBuffer){ int type=USB_RXBuffer[2]; MESSAGES ms=MESSAGES.values()[type]; switch(ms) { case READ_PARAMETER_VALUE: // read parameter values switch(prm){ case PARAMETER_DRIVE_MODE: // paramet drive mode Helper.paramDriveMod =(Integer.toString(((USB_RXBuffer[4]<< 8)&0xff00))); System.out.println(Helper.paramDriveMod+"drive mode is selectd ");//here it shows the value that I need. ..........}}//let say end switch and method and the following is an third class method use the above class method public void buttonSwitch(int value) throws InterruptedException{ boolean bool=true; int c=0; int delay=(int) Math.random(); while(bool){ int param=3; PARAMETERS prm=PARAMETERS.values()[param]; switch(value){ case 0: value=1; while(c<5){ Thread.sleep(delay); protocol.onSending(3,prm.PARAMETER_DRIVE_MODE.ordinal(),dataToRead,dataToRead.length);//read drive mode System.out.println(Helper.paramDriveMod+" drive mode is ..........in wile loop");//here it shows null value }}//let say end switch and method what is the reason that this variable lose its value?

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  • Scratch the screen to display an image in android

    - by user1008497
    i am working on a android project for my assignment. i am trying to make a scratch image application, you know it's like we scratch the screen to get rid the blocking layer to display the image. but the problem is i don't know where to start. i have searching in stackoverflow's questions that related to this but that's not help. from my search there, i found a clue for this project is using Bitmap.getPixel(int x, int y). so, in my thought i have to get pixel from bitmap and paint it to canvas. but i don't know how to implement it? or anyone has a better method for this? Could anyone please help me? Any tutorials on this kind of thing or related topics? Thanks in advance! here's my sample code: @Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(w, h, oldw, oldh); tw = w; th = h; eraseableBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888); mCanvas = new Canvas(eraseableBitmap); Bitmap muteableBitmap = Bitmap.createBitmap(eraseableBitmap.getWidth(), eraseableBitmap.getHeight(), Bitmap.Config.ARGB_8888); } @Override public boolean onTouchEvent(MotionEvent event) { static_x = event.getX(); static_y = event.getY(); if (event.getAction() == MotionEvent.ACTION_DOWN) { touch_start(static_x, static_y); } if (event.getAction() == MotionEvent.ACTION_MOVE) { touch_move(static_x, static_y); } if (event.getAction() == MotionEvent.ACTION_UP) { touch_up(); } return true; }

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  • What are CAD apps written in, and how are they organized ?

    - by ldigas
    What are CAD applications (Rhino, Autocad) of today written in and how are they organized internally ? I gave as an example, Autocad and Rhino, although I would love to hear of other examples as well. I'm particularly interested in knowing what is their backend written in (multilanguage ?) and how is it organized, and how do they handle their frontend (GUI) in real time ? Do they use native windows API's or some libraries of their own, since I imagine, as good as may be, the open source solutions on today's market won't cut it. I may be wrong ... As most of you who have used them know, they handle amongs other things relatively complex rotational operations in realtime (shading is not interesting me). I've been doing some experiments with several packages recently, and for some larger models found that there is considerable difference in speed in, for example, programed rotation (big full ship models) amongst some of them (which I won't name). So I'm wondering about their internals ... Also, if someone knows of some book on the subject, I'd be interested to hear of it.

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  • How to limit setAccessible to only "legitimate" uses?

    - by polygenelubricants
    The more I learned about the power of setAccessible, the more astonished I am at what it can do. This is adapted from my answer to the question (Using reflection to change static final File.separatorChar for unit testing). import java.lang.reflect.*; public class EverythingIsTrue { static void setFinalStatic(Field field, Object newValue) throws Exception { field.setAccessible(true); Field modifiersField = Field.class.getDeclaredField("modifiers"); modifiersField.setAccessible(true); modifiersField.setInt(field, field.getModifiers() & ~Modifier.FINAL); field.set(null, newValue); } public static void main(String args[]) throws Exception { setFinalStatic(Boolean.class.getField("FALSE"), true); System.out.format("Everything is %s", false); // "Everything is true" } } You can do truly outrageous stuff: public class UltimateAnswerToEverything { static Integer[] ultimateAnswer() { Integer[] ret = new Integer[256]; java.util.Arrays.fill(ret, 42); return ret; } public static void main(String args[]) throws Exception { EverythingIsTrue.setFinalStatic( Class.forName("java.lang.Integer$IntegerCache") .getDeclaredField("cache"), ultimateAnswer() ); System.out.format("6 * 9 = %d", 6 * 9); // "6 * 9 = 42" } } Presumably the API designers realize how abusable setAccessible can be, but must have conceded that it has legitimate uses to provide it. So my questions are: What are the truly legitimate uses for setAccessible? Could Java has been designed as to NOT have this need in the first place? What would the negative consequences (if any) of such design be? Can you restrict setAccessible to legitimate uses only? Is it only through SecurityManager? How does it work? Whitelist/blacklist, granularity, etc? Is it common to have to configure it in your applications?

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  • PHP mail() function not delivering mail

    - by Ryan Jones
    Hi there, I have a slight problem. I am using a working script (works on my testing account - shared server) to send a mail through PHP using the mail() function. I just got a dedicated server, and I haven't been able to get the function to work. I've spent the last 10 or so hours reading various documentations on BIND (for the SPF record), dovecot, sendmail and postfix trying various things to get this to work. There is clearly something that I am missing. So we know the PHP code works fine. All the headers are fine everything. We know this as it's a direct copy from my testing account. So the problem must arise somewhere in the server config. The path to sendmail is correct, and sendmail is (apparently) working fine. I've set up the script to now deliver "Sent" or "Error" based on the boolean result from the PHP mail() function. That is: if(mail($blah,$blah,$blah,$blah,$blah)) { echo "Sent"; } else { echo "Error";} And the result ALWAYS comes up as "Sent" - however, the email never arrives. Can someone suggest things to check, as I'm completely new to this (24 hours or so!). Thanks in advance. Ryan

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  • Flexible forms and supporting database structure

    - by sunwukung
    I have been tasked with creating an application that allows administrators to alter the content of the user input form (i.e. add arbitrary fields) - the contents of which get stored in a database. Think Modx/Wordpress/Expression Engine template variables. The approach I've been looking at is implementing concrete tables where the specification is consistent (i.e. user profiles, user content etc) and some generic field data tables (i.e. text, boolean) to store non-specific values. Forms (and model fields) would be generated by first querying the tables and retrieving the relevant columns - although I've yet to think about how I would setup validation. I've taken a look at this problem, and it seems to be indicating an EAV type approach - which, from my brief research - looks like it could be a greater burden than the blessings it's flexibility would bring. I've read a couple of posts here, however, which suggest this is a dangerous route: How to design a generic database whose layout may change over time? Dynamic Database Schema I'd appreciate some advice on this matter if anyone has some to give regards SWK

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  • Why does GLSL's arithmetic functions yield so different results on the iPad than on the simulator?

    - by cheeesus
    I'm currently chasing some bugs in my OpenGL ES 2.0 fragment shader code which is running on iOS devices. The code runs fine in the simulator, but on the iPad it has huge problems and some of the calculations yield vastly different results, I had for example 0.0 on the iPad and 4013.17 on the simulator, so I'm not talking about small differences which could be the result of some rounding errors. One of the things I noticed is that, on the iPad, float1 = pow(float2, 2.0); can yield results which are very different from the results of float1 = float2 * float2; Specifically, when using pow(x, 2.0) on a variable containing a larger negative number like -8, it seemed to return a value which satified the condition if (powResult <= 0.0). Also, the result of both operations (pow(x, 2.0) as well as x*x) yields different results in the simulator than on the iPad. Used floats are mediump, but I get the same stuff with highp. Is there a simple explanation for those differences? I'm narrowing the problem down, but it takes so much time, so maybe someone can help me here with a simple explanation.

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  • MS Excel automation without macros in the generated reports. Any thoughts?

    - by ezeki77
    Hello! I know that the web is full of questions like this one, but I still haven't been able to apply the answers I can find to my situation. I realize there is VBA, but I always disliked having the program/macro living inside the Excel file, with the resulting bloat, security warnings, etc. I'm thinking along the lines of a VBScript that works on a set of Excel files while leaving them macro-free. Now, I've been able to "paint the first column blue" for all files in a directory following this approach, but I need to do more complex operations (charts, pivot tables, etc.), which would be much harder (impossible?) with VBScript than with VBA. For this specific example knowing how to remove all macros from all files after processing would be enough, but all suggestions are welcome. Any good references? Any advice on how to best approach external batch processing of Excel files will be appreciated. Thanks! PS: I eagerly tried Mark Hammond's great PyWin32 package, but the lack of documentation and interpreter feedback discouraged me.

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  • Algorithm complexity question

    - by Itsik
    During a recent job interview, I was asked to give a solution to the following problem: Given a string s (without spaces) and a dictionary, return the words in the dictionary that compose the string. For example, s= peachpie, dic= {peach, pie}, result={peach, pie}. I will ask the the decision variation of this problem: if s can be composed of words in the dictionary return yes, otherwise return no. My solution to this was in backtracking (written in Java) public static boolean words(String s, Set<String> dictionary) { if ("".equals(s)) return true; for (int i=0; i <= s.length(); i++) { String pre = prefix(s,i); // returns s[0..i-1] String suf = suffix(s,i); // returns s[i..s.len] if (dictionary.contains(pre) && words(suf, dictionary)) return true; } return false; } public static void main(String[] args) { Set<String> dic = new HashSet<String>(); dic.add("peach"); dic.add("pie"); dic.add("1"); System.out.println(words("peachpie1", dic)); // true System.out.println(words("peachpie2", dic)); // false } What is the time complexity of this solution? I'm calling recursively in the for loop, but only for the prefix's that are in the dictionary. Any idea's?

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  • DataGridView update datasource directly after changed Checkbox value

    - by SchlaWiener
    I have a System.Windows.Forms DataGridView that is bound to a List<MyObject>. The class MyObject contains a boolean property that is bound to DataGridViewCheckboxCell within the DataGridView. public class MyObject { public decimal DefaultValue {get; set; } public bool HasCustomValue {get;set; } public decimal CustomValue {get;set; } public decimal CurrentValue { get { return HasCustomValue ? CustomValue : DefaultValue; } } If I change the value of HasCustomValue another (readonly) property CurrentValue changes it's value, too. That is done by implementing the INotifyPropertyChanged event (I left that part in the source example for simplicity) If I changed HasCustomValue from outside the DataGridView, the column bound to CurrentValue gets updated immediately. Howevery, If the users enables/disables the checkbox, HasCustomValue is not changed in the underlying datasource unless he leaves the column by clicking with the mouse or pressing the TAB key. Is there a way to force the grid to update the datasource directly after changing a checkbox value? If I bind a Control Property I have the ability to set the DataSourceUpdateMode to Windows.Forms.DataSourceUpdateMode.OnPropertyChanged but I haven't found anything like that in a DataGridView

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  • JTree TreePath casting problem

    - by newbie123
    I got this casting problem java.lang.String cannot be cast to java.io.File, when I trying to do this TreePath p = new TreePath(new Object[] {"src","file","My Diary" }); This is my jtree file model class FileTreeModel implements TreeModel { private FileNode root; public FileTreeModel(String directory) { root = new FileNode(directory); } public Object getRoot() { return root; } public Object getChild(Object parent, int index) { FileNode parentNode = (FileNode) parent; return new FileNode(parentNode, parentNode.listFiles()[index].getName()); } public int getChildCount(Object parent) { FileNode parentNode = (FileNode) parent; if (parent == null || !parentNode.isDirectory() || parentNode.listFiles() == null) { return 0; } return parentNode.listFiles().length; } public boolean isLeaf(Object node) { return (getChildCount(node) == 0); } public int getIndexOfChild(Object parent, Object child) { FileNode parentNode = (FileNode) parent; FileNode childNode = (FileNode) child; return Arrays.asList(parentNode.list()).indexOf(childNode.getName()); } public void valueForPathChanged(TreePath path, Object newValue) { } public void addTreeModelListener(TreeModelListener l) { } public void removeTreeModelListener(TreeModelListener l) { } } class FileNode extends java.io.File { public FileNode(String directory) { super(directory); } public FileNode(FileNode parent, String child) { super(parent, child); } @Override public String toString() { return getName(); } }

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  • iPhone: How to Determine Average Light/Dark of an Area of an UIImage

    - by TechZen
    I need to place labels with a transparent background over a variable-content UIImage. Readability will vary significantly depending on the relationship between the color of the label's text and the color/luminosity of the area of the image displayed under the label. Since the image will be constantly changing, the color of the label's text needs to change in sync. I have found several techniques for determining the color, perceived luminosity etc of a single pixel. However, I need to rather quickly (while a view loads) determine the rough perceived color/luminosity of an area of the UIImage under the frame of the UILabel. I presume I will also need to measure the alpha because the same color/luminosity looks different at different alpha values. Is there a way to calculate such a value for an area? Will I be reduced to simply summing pixels? If it comes to that, is there an algorithm to accomplish this? I've thought of two possible approaches: Perform some "folding" operations i.e. combining pixels from one half of the area to the other half. Then repeat until I get a single value. Would this be practical? How would you logically combine pixels to average their perceived color/luminosity? Sample a statistically significant number of pixels in the area and then combine them (somehow) to get a rough measure. I think this problem comes up a lot these days with people being so found of customizing backgrounds. Seems like something that would be worth my time to bang out a category or class to handle this and then share it around.

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  • manyToOne is creating new products

    - by user788721
    I am trying to implement Sylius Cart Bundle, but every time I add a product to the cart, a new product is created. This is probably link to my line: cascade: ["persist", "remove"] In my YAML File: Pharmacie\FrontBundle\Entity\CartItem: type: entity table: app_cart_item manyToOne: produit: targetEntity: Pharmacie\FrontBundle\Entity\Product cascade: ["persist", "remove"] joinColumn: name: product_id referencedColumnName: id But if take it off, I get an error: A new entity was found through the relationship 'Pharmacie\FrontBundle\Entity\CartItem#produit' that was not configured to cascade persist operations for entity: 3test2. To solve this issue: Either explicitly call EntityManager#persist() on this unknown entity or configure cascade persist this association in the mapping for example @ManyToOne(..,cascade={"persist"}) According to the doctrine doc, this error occurs when you set a new object. But I am only getting an existing object By ID: $product = $this->getProductRepository()->find($productId); $item->setProduit($product); //this generates the error $item->setUnitPrice(5); //this works fine I don't understand why it's save as a new object. If I use merge instead of persist, I get the same error: A new entity was found through the relationship...

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