Search Results

Search found 11639 results on 466 pages for 'numerical methods'.

Page 32/466 | < Previous Page | 28 29 30 31 32 33 34 35 36 37 38 39  | Next Page >

  • What's a good way to add a large number of small floats together?

    - by splicer
    Say you have 100000000 32-bit floating point values in an array, and each of these floats has a value between 0.0 and 1.0. If you tried to sum them all up like this result = 0.0; for (i = 0; i < 100000000; i++) { result += array[i]; } you'd run into problems as result gets much larger than 1.0. So what are some of the ways to more accurately perform the summation?

    Read the article

  • Where should the line between property and method be?

    - by Catskul
    For many situations it is obvious whether something should be a property or a method however there are items that might be considered ambiguous. Obvious Properties: "name" "length" Obvious Methods: "SendMessage" "Print" Ambiguous: "Valid" / "IsValid" / "Validate" "InBounds" / "IsInBounds" / "CheckBounds" "AverageChildValue" / "CalcAverageChildValue" "ColorSaturation" / "SetColorSaturation" I suppose I would lean towards methods for the ambiguous, but does anyone know of a rule or convention that helps decide this? E.g. should all properties be O(1)? Should a property not be able to change other data (ColorSaturation might change R,G,B values)? Should it not be a property if there is calculation or aggregation? Just from an academic perspective, (and not because I think it's a good idea) is there a reason not to go crazy with properties and just make everything that is an interrogation of the class without taking an argument, and everything that can be changed about the class with a single argument and cant fail, a property?

    Read the article

  • Using methods on 2 input files - 2nd is printing multiple times - Java

    - by Aaa
    I have the following code to read in text, store in a hashmap as bigrams (with other methods to sort them by frequency and do v. v. basic additive smoothing. I had it working great for one language input file (english) and then I want to expand it for the second language input file (japanese - doens;t matter what it is I suppose) using the same methods but the Japanese bigram hashmap is printing out 3 times in a row with diff. values. I've tried using diff text in the input file, making sure there are no gaps in text etc. I've also put print statements at certain places in the Japanese part of the code to see if I can get any clues but all the print statements are printing each time so I can't work out if it is looping at a certain place. I have gone through it with a fine toothcomb but am obviously missing something and slowly going crazy here - any help would be appreciated. thanks in advance... package languagerecognition2; import java.lang.String; import java.io.InputStreamReader; import java.util.*; import java.util.Iterator; import java.util.List.*; import java.util.ArrayList; import java.util.AbstractMap.*; import java.lang.Object; import java.io.*; import java.util.Enumeration; import java.util.Arrays; import java.lang.Math; public class Main { /** public static void main(String[] args) { //training English ----------------------------------------------------------------- File file = new File("english1.txt"); StringBuffer contents = new StringBuffer(); BufferedReader reader = null; try { reader = new BufferedReader(new FileReader(file)); String test = null; //test = reader.readLine(); // repeat until all lines are read while ((test = reader.readLine()) != null) { test = test.toLowerCase(); char[] charArrayEng = test.toCharArray(); HashMap<String, Integer> hashMapEng = new HashMap<String, Integer>(bigrams(charArrayEng)); LinkedHashMap<String, Integer> sortedListEng = new LinkedHashMap<String, Integer>(sort(hashMapEng)); int sizeEng=sortedListEng.size(); System.out.println("Total count of English bigrams is " + sizeEng); LinkedHashMap<String, Integer> smoothedListEng = new LinkedHashMap<String, Integer>(smooth(sortedListEng, sizeEng)); //print linkedHashMap to check values Set set= smoothedListEng.entrySet(); Iterator iter = set.iterator ( ) ; System.out.println("Beginning English"); while ( iter.hasNext()) { Map.Entry entry = ( Map.Entry ) iter.next ( ) ; Object key = entry.getKey ( ) ; Object value = entry.getValue ( ) ; System.out.println( key+" : " + value); } System.out.println("End English"); }//end while }//end try catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } finally { try { if (reader != null) { reader.close(); } } catch (IOException e) { e.printStackTrace(); } } //End training English----------------------------------------------------------- //Training japanese-------------------------------------------------------------- File file2 = new File("japanese1.txt"); StringBuffer contents2 = new StringBuffer(); BufferedReader reader2 = null; try { reader2 = new BufferedReader(new FileReader(file2)); String test2 = null; //repeat until all lines are read while ((test2 = reader2.readLine()) != null) { test2 = test2.toLowerCase(); char[] charArrayJap = test2.toCharArray(); HashMap<String, Integer> hashMapJap = new HashMap<String, Integer>(bigrams(charArrayJap)); //System.out.println( "bigrams stage"); LinkedHashMap<String, Integer> sortedListJap = new LinkedHashMap<String, Integer>(sort(hashMapJap)); //System.out.println( "sort stage"); int sizeJap=sortedListJap.size(); //System.out.println("Total count of Japanese bigrams is " + sizeJap); LinkedHashMap<String, Integer> smoothedListJap = new LinkedHashMap<String, Integer>(smooth(sortedListJap, sizeJap)); System.out.println( "smooth stage"); //print linkedHashMap to check values Set set2= smoothedListJap.entrySet(); Iterator iter2 = set2.iterator(); System.out.println("Beginning Japanese"); while ( iter2.hasNext()) { Map.Entry entry2 = ( Map.Entry ) iter2.next ( ) ; Object key = entry2.getKey ( ) ; Object value = entry2.getValue ( ) ; System.out.println( key+" : " + value); }//end while System.out.println("End Japanese"); }//end while }//end try catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } finally { try { if (reader2 != null) { reader2.close(); } } catch (IOException e) { e.printStackTrace(); } } //end training Japanese--------------------------------------------------------- } //end main (inner)

    Read the article

  • How can I add floats together in different orders, and always get the same total?

    - by splicer
    Let's say I have three 32-bit floating point values, a, b, and c, such that (a + b) + c != a + (b + c). Is there summation algorithm, perhaps similar to Kahan summation, that guarantees that these values can be summed in any order and always arrive at the exact same (fairly accurate) total? I'm looking for the general case (i.e. not a solution that only deals with 3 numbers). Is arbitrary precision arithmetic the only way to go? I'm dealing with very large data sets, so I'd like to avoid the overhead of using arbitrary precision arithmetic if possible. Thanks!

    Read the article

  • Getting hold of a reference to the object created by JOptionPane static methods

    - by user548240
    Hi, I wonder if it is possible to get hold of a reference to the (JDialog?) object created by one of those static methods of JOptionPane (e.g. showMessageDialog)? I intend to modify the position where the dialog appears on the screen. More specifically, I want the dialog to appear at the top-left corner of the main app window, instead of the centre of the window by default. So having a reference to the object would enable me to use setLocation to achieve the desired effect... Any suggestion would be appreciated! Thanks!

    Read the article

  • Calling asynchronous methods from wcf service

    - by hima
    In my asp.net application, I am using wcf service to get all the business logic. I am using that service reference in my application to work with that. Now adding that service reference is giving another option Update service reference is giving Generate asynchronous operations. If I check the option and add the service will it generate asynchronous methods for my existing service. If so how do I use the metohd. Let me know the way for that. Thanks, Hima.

    Read the article

  • Please explain class methods

    - by user1209902
    I'm finding it difficult to understand when it is necessary to create class methods. From what I've read, they are important for creating new objects, but I do not see how. The following class create a simple shape black rectangle. Can anyone show me how to incorporate a class method to do something that I could not do with an instance method? Shape.h #import <UIKit/UIKit.h> @interface Shape : UIView; - (id) initWithX: (int)xVal andY: (int)yVal; @end Shape.m #import "Shape.h" @implementation Shape - (id) initWithX:(int )xVal andY:(int)yVal { self = [super init]; UIView *shape = [[UIView alloc] initWithFrame:CGRectMake(xVal, yVal, 10, 10)]; shape.backgroundColor = [UIColor blackColor]; [self addSubview:shape]; return self; } @end

    Read the article

  • Overload and hide methods in Java

    - by Marco
    Hi, i have an abstract class BaseClass with a public insert() method: public abstract class BaseClass { public void insert(Object object) { // Do something } } which is extended by many other classes. For some of those classes, however, the insert() method must have additional parameters, so that they instead of overriding it I overload the method of the base class with the parameters required, for example: public class SampleClass extends BaseClass { public void insert(Object object, Long param){ // Do Something } } Now, if i instantiate the SampleClass class, i have two insert() methods: SampleClass sampleClass = new SampleClass(); sampleClass.insert(Object object); sampleClass.insert(Object object, Long param); what i'd like to do is to hide the insert() method defined in the base class, so that just the overload would be visible: SampleClass sampleClass = new SampleClass(); sampleClass.insert(Object object, Long param); Could this be done in OOP?

    Read the article

  • [C++] Question on Virtual Methods

    - by bobber205
    IF both methods are declared as virtual, shouldn't both instances of Method1() that are called be the derived class's Method1()? I am seeing BASE then DERIVED called each time. I am doing some review for an interview and I want to make sure I have this straight. xD class BaseClass { public: virtual void Method1() { cout << "Method 1 BASE" << endl; } }; class DerClass: public BaseClass { public: virtual void Method1() { cout << "Method 1 DERVIED" << endl; } }; DerClass myClass; ((BaseClass)myClass).Method1(); myClass.Method1(); Method 1 BASE Method 1 DERVIED

    Read the article

  • Best Data Access Methods for New Web Application

    - by user98454
    I'm building a new web application project and am confused by the numerous methods of performing data access. I'm backending on SQL and a bit confused whether to use LINQ to SQL or trtaditional ADO.net ? what are the advantages and disadvantages of using LINQ/SQL over ADO.net? If it is ADO.net,then what is the best way to retrieve data means either calling the stored procedures or directly calling the t-sql code? My question is what is cleanes and most effiecient and professional way of creating DAL for webapplication in asp.net? Thanks

    Read the article

  • Using JS Methods in jQuery

    - by Wasabi
    In the following code snippet, the String.fromCharCode is used, can all JS methods be used within jQuery? Perhaps a noob question, but better to ask and prove a noob, then assume and be a fool. // Invoke setBodyClass when a key is pressed $(document).keyup(function(){ switch (String.fromCharCode(event.keyCode)){ case 'D': setBodyClass('default'); break; case 'N': setBodyClass('narrow'); break; case 'L': setBodyClass('large'); break; } });//end keyup

    Read the article

  • Bootstrap jquery methods Magento's prototype lib

    - by user1722527
    Wonder if anyone has had this issue. I've integrated Bootstrap nicely into a Magento theme I'm building, all good. That is, until I try using the accordian functions. There seems to be an issue with the code finding the Prototype Libs Methods instead of jQuery's. I've tried the usual fixes, $ - jQuery and no conflict but it only works when I disable the prototype lib - which obviously is not good. Anyone out there come across this and can advise me on a work round? At the moment I'm resigned to using Scriptaculous for the accordian.

    Read the article

  • Is It Worth Using Bitwise Operators In Methods?

    - by user1626141
    I am very new to Java (and programming in general, my previous experience is with ActionScript 2.0 and some simple JavaScript), and I am working my way slowly and methodically through Java: A Beginner's Guide by Herbert Schildt. It is an incredible book. For one thing, I finally understand more-or-less what bitwise operators (which I first encountered in ActionScript 2.0) do, and that they are more efficient than other methods for certain sums. My question is, is it more efficient to use a method that uses, say, a shift right, to perform all your divisions/2 (or divisions/even) for you in a large program with many calculations (in this case, a sprawling RPG), or is it more efficient to simply use standard mathematical operations because the compiler will optimise it all for you? Or, am I asking the wrong question entirely?

    Read the article

  • Is there an autorelease pool in class methods?

    - by mystify
    I have an class method which generates an UIView, like this: + (UIImage*)imageWithFileName:(NSString*)imgFile { UIImage *img = nil; NSBundle *appBundle = [NSBundle mainBundle]; NSString *resourcePath = [appBundle pathForResource:imgFile ofType:nil]; if (resourcePath != nil) { NSURL *imageURL = [NSURL fileURLWithPath:resourcePath]; NSData *data = [[NSData alloc] initWithContentsOfURL:imageURL]; img = [UIImage imageWithData:data]; // should be autoreleased!! [data release]; } return img; } However, when I use this, the image data is NEVER freed. There is definitely a memory bug with this, although I didn't break any memory management rule I am aware of. My guess is that because this is a class method which gets called from instance methods, There is no active autorelease pool in place or it's one that only gets drained when I quit the app. Could that be right?

    Read the article

  • Skipping authorization for certain methods

    - by mathee
    Per the Agile Development book, I have an Admin MVC that controls how users log in. In ApplicationController, I have a before_filter that checks for authorization. So, this will check that the user has logged in for every page. The problem is that I want everyone to be able to access the new method, for example, in Users (that is, anyone should be able to create a new user -- naturally! Only admin users should have access to the other methods in UsersController such as edit, etc.). What's the best way to do that?

    Read the article

  • Passing Session[] and Request[] to Methods in C#

    - by NYARROW
    In C#, How do you pass the Session[] and Request[] objects to a method? I would like to use a method to parse out Session and Request paramaters for a .aspx page to reduce the size of my Page_Load method. I am passing quite a few variables, and need to support both POSTand GET methods. For most calls, not all variables are present, so I have to test every variable multiple ways, and the code gets long... This is what I am trying to do, but I can't seem to properly identify the Session and Request paramaters (this code will not compile, because the arrays are indexed by number) static string getParam( System.Web.SessionState.HttpSessionState[] Session, System.Web.HttpRequest[] Request, string id) { string rslt = ""; try { rslt = Session[id].ToString(); } catch { try { rslt = Request[id].ToString(); } catch { } } return rslt; } From Page_Load, I want to call this method as follows to retrieve the "MODE" paramater: string rslt; rslt = getParam(Session, Request, "MODE"); Thanks!

    Read the article

  • Access shell methods in controller? Cake PHP 1.3

    - by anonymous coward
    I wrote a shell method in CakePHP 1.3 that has a return value. I'd like to be able to access that method from within a controller, so that I can pass its return value into the View. I'm not sure how to access those methods appropriately from within the controller. Have I done it wrong? I could easily duplicate the code, but I'd like to "keep it DRY", and the actual functionality, I believe, doesn't belong with this particular controller - I just need it's return value in this particular view.

    Read the article

  • PHP: Is_numeric returns false on 0

    - by Industrial
    Hi everyone, Is_numeric() as well as is_int() returns false if the value is 0. What can i do instead to verify that a specific value is numbers only in PHP? Are we heading straight for the Regular Expressions camp, or are there some nice, handy feature for this out there already? Thanks!

    Read the article

  • Outer product using CBLAS

    - by The Dude
    I am having trouble utilizing CBLAS to perform an Outer Product. My code is as follows: //===SET UP===// double x1[] = {1,2,3,4}; double x2[] = {1,2,3}; int dx1 = 4; int dx2 = 3; double X[dx1 * dx2]; for (int i = 0; i < (dx1*dx2); i++) {X[i] = 0.0;} //===DO THE OUTER PRODUCT===// cblas_dgemm(CblasRowMajor, CblasNoTrans, CblasTrans, dx1, dx2, 1, 1.0, x1, dx1, x2, 1, 0.0, X, dx1); //===PRINT THE RESULTS===// printf("\nMatrix X (%d x %d) = x1 (*) x2 is:\n", dx1, dx2); for (i=0; i<4; i++) { for (j=0; j<3; j++) { printf ("%lf ", X[j+i*3]); } printf ("\n"); } I get: Matrix X (4 x 3) = x1 (*) x2 is: 1.000000 2.000000 3.000000 0.000000 -1.000000 -2.000000 -3.000000 0.000000 7.000000 14.000000 21.000000 0.000000 But the correct answer is found here: https://www.sharcnet.ca/help/index.php/BLAS_and_CBLAS_Usage_and_Examples I have seen: Efficient computation of kronecker products in C But, it doesn't help me because they don't actually say how to utilize dgemm to actually do this... Any help? What am I doing wrong here?

    Read the article

  • [Scala] Applying overloaded, typed methods on a collection

    - by stephanos
    I'm quite new to Scala and struggling with the following: I have database objects (type of BaseDoc) and value objects (type of BaseVO). Now there are multiple convert methods (all called 'convert') that take an instance of an object and convert it to the other type accordingly - like this: def convert(doc: ClickDoc): ClickVO = ... def convert(doc: PointDoc): PointVO = ... def convert(doc: WindowDoc): WindowVO = ... Now I sometimes need to convert a list of objects. How would I do this - I tried: def convert[D <: BaseDoc, V <: BaseVO](docs: List[D]):List[V] = docs match { case List() => List() case xs => xs.map(doc => convert(doc)) } Which results in 'overloaded method value convert with alternatives ...'. I tried to add manifest information to it, but couldn't make it work. I couldn't even create one method for each because it'd say that they have the same parameter type after type erasure (List). Ideas welcome!

    Read the article

  • Different methods using Functors/Delegates in c#

    - by mo alaz
    I have a method that I call multiple times, but each time a different method with a different signature is called from inside. public void MethodOne() { //some stuff *MethodCall(); //some stuff } So MethodOne is called multiple times, each time with a different *MethodCall(). What I'm trying to do is something like this : public void MethodOne(Func<> MethodCall) { //some stuff *MethodCall; //some stuff } but the Methods that are called each have a different return type and different parameters. Is there a way to do this using Functors? If not, how would I go about doing this? Thank you!

    Read the article

  • Android remote service doesn't call service methods

    - by tarantel
    Hello, I'm developing a GPS tracking software on android. I need IPC to control the service from different activities. So I decide to develop a remote service with AIDL. This wasn't a big problem but now it's always running into the methods of the interface and not into those of my service class. Maybe someone could help me? Here my ADIL file: package test.de.android.tracker interface ITrackingServiceRemote { void startTracking(in long trackId); void stopTracking(); void pauseTracking(); void resumeTracking(in long trackId); long trackingState(); } And the here a short version of my service class: public class TrackingService extends Service implements LocationListener{ private LocationManager mLocationManager; private TrackDb db; private long trackId; private boolean isTracking = false; @Override public void onCreate() { super.onCreate(); mNotificationManager = (NotificationManager) this .getSystemService(NOTIFICATION_SERVICE); mLocationManager = (LocationManager) getSystemService(LOCATION_SERVICE); db = new TrackDb(this.getApplicationContext()); } @Override public void onStart(Intent intent, int startId) { super.onStart(intent, startId); } @Override public void onDestroy(){ //TODO super.onDestroy(); } @Override public IBinder onBind(Intent intent){ return this.mBinder; } private IBinder mBinder = new ITrackingServiceRemote.Stub() { public void startTracking(long trackId) throws RemoteException { TrackingService.this.startTracking(trackId); } public void pauseTracking() throws RemoteException { TrackingService.this.pauseTracking(); } public void resumeTracking(long trackId) throws RemoteException { TrackingService.this.resumeTracking(trackId); } public void stopTracking() throws RemoteException { TrackingService.this.stopTracking(); } public long trackingState() throws RemoteException { long state = TrackingService.this.trackingState(); return state; } }; public synchronized void startTracking(long trackId) { // request updates every 250 meters or 0 sec this.trackId = trackId; mLocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 250, this); isTracking = true; } public synchronized long trackingState() { if(isTracking){ return trackId; } else return -1; } public synchronized void stopTracking() { if(isTracking){ mLocationManager.removeUpdates(this); isTracking = false; } else Log.i(TAG, "Could not stop because service is not tracking at the moment"); } public synchronized void resumeTracking(long trackId) { if(!isTracking){ this.trackId = trackId; mLocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 250, this); isTracking = true; } else Log.i(TAG, "Could not resume because service is tracking already track " + this.trackId); } public synchronized void pauseTracking() { if(isTracking){ mLocationManager.removeUpdates(this); isTracking = false; } else Log.i(TAG, "Could not pause because service is not tracking at the moment"); } public void onLocationChanged(Location location) { //TODO } For easier access from the client I wrote a ServiceManager class which sets up the ServiceConnection and you can call the service methods. Here my code for this: public class TrackingServiceManager{ private static final String TAG = "TrackingServiceManager"; private ITrackingServiceRemote mService = null; private Context mContext; private Boolean isBound = false; private ServiceConnection mServiceConnection; public TrackingServiceManager(Context ctx){ this.mContext = ctx; } public void start(long trackId) { if (isBound && mService != null) { try { mService.startTracking(trackId); } catch (RemoteException e) { Log.e(TAG, "Could not start tracking!",e); } } else Log.i(TAG, "No Service bound! 1"); } public void stop(){ if (isBound && mService != null) { try { mService.stopTracking(); } catch (RemoteException e) { Log.e(TAG, "Could not stop tracking!",e); } } else Log.i(TAG, "No Service bound!"); } public void pause(){ if (isBound && mService != null) { try { mService.pauseTracking(); } catch (RemoteException e) { Log.e(TAG, "Could not pause tracking!",e); } } else Log.i(TAG, "No Service bound!"); } public void resume(long trackId){ if (isBound && mService != null) { try { mService.resumeTracking(trackId); } catch (RemoteException e) { Log.e(TAG, "Could not resume tracking!",e); } } else Log.i(TAG, "No Service bound!"); } public float state(){ if (isBound && mService != null) { try { return mService.trackingState(); } catch (RemoteException e) { Log.e(TAG, "Could not resume tracking!",e); return -1; } } else Log.i(TAG, "No Service bound!"); return -1; } /** * Method for binding the Service with client */ public boolean connectService(){ mServiceConnection = new ServiceConnection() { @Override public void onServiceConnected(ComponentName name, IBinder service) { TrackingServiceManager.this.mService = ITrackingServiceRemote.Stub.asInterface(service); } } @Override public void onServiceDisconnected(ComponentName name) { if (mService != null) { mService = null; } } }; Intent mIntent = new Intent("test.de.android.tracker.action.intent.TrackingService"); this.isBound = this.mContext.bindService(mIntent, mServiceConnection, Context.BIND_AUTO_CREATE); return this.isBound; } public void disconnectService(){ this.mContext.unbindService(mServiceConnection); this.isBound = false; } } If i now try to call a method from an activity for example start(trackId) nothing happens. The binding is OK. When debugging it always runs into the startTracking() in the generated ITrackingServiceRemote.java file and not into my TrackingService class. Where is the problem? I can't find anything wrong. Thanks in advance! Tobias

    Read the article

  • How to check any undocumented methods provided by apple?

    - by Mahbubur R Aaman
    The following tools is provided by Apple dlopen dlsym objc_getClass sel_registerName objc_msgSend Those are listing Objective-C selectors, or strings. Objective-C selectors are stored in a special region of the binary, and therefore Apple could extract the content from there, and check if you've used some undocumented Objective-C methods. How to utilize these tools to find undocumented Objective-C methods? EDIT: Recently, one of my App rejected due to using one undocumented methods. -[UIDevice setOrientation] Since, selectors are independent from the class you're messaging, even if my custom class defines -setOrientation: irrelevant to UIDevice, there will be a possbility of being rejected.

    Read the article

  • How do I fix a "E: The method driver /usr/lib/apt/methods/http could not be found." error?

    - by Abe
    I tried updating my packages from the terminal and this is what I got: $ sudo apt-get update E: The method driver /usr/lib/apt/methods/http could not be found. E: The method driver /usr/lib/apt/methods/http could not be found. E: The method driver /usr/lib/apt/methods/http could not be found. E: The method driver /usr/lib/apt/methods/http could not be found. E: The method driver /usr/lib/apt/methods/http could not be found. What does this mean? I'm using the United States mirror an I've tried using the main server for the mirror and I keep getting the same result is this because there are no updates?

    Read the article

< Previous Page | 28 29 30 31 32 33 34 35 36 37 38 39  | Next Page >