Search Results

Search found 42090 results on 1684 pages for 'mean square method'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 497/1684 | < Previous Page | 493 494 495 496 497 498 499 500 501 502 503 504  | Next Page >

  • C Programming: malloc and free within a loop

    - by kouei
    Hi all, I just started out with C and have very little knowledge about performance issues with malloc() and free(). My question is as such: if I were to call malloc() followed by free() in a while-loop that loops for, say, 20 times, would it run slower compared to if I were to call free() outside the loop? I am actually using the first method to allocate memory to a buffer, read a string of variable length in a file, perform some string operation, and then clear the buffer after every iteration. If my method results in a lot of overhead then I'd like to ask for a better way for me to achieve the same results. Sorry for my bad English. Thanks and regards, K

    Read the article

  • what does macosx-version-min imply?

    - by Quincy
    When I pass compiler flag "-mmacosx-version-min=10.5", what does it mean? I think it implies the result binary is x86, not ppc, but is it 32 bits or 64 bits? I'm compiling on snow leopard, so default output binary is 64 bits. I'm not passing -universal, it's not 32bit-64bit universal binary, I think.

    Read the article

  • Eye Detection Problem In Opencv

    - by iva123
    Hi, I'm trying to convert this c code(http://nashruddin.com/OpenCV_Eye_Detection) to the python code, but in c style, he used cvROI thing, since ROI functions are not supported by python-opencv, I tried cvGetSubRect so Here is the eye detection part of the code : eye_region = cvGetSubRect(image,cvRect(face.x,int(face.y + (face.height/4)),face.width,int(face.height/2))) eyes = cvHaarDetectObjects(eye_region,eyeCascade,memo,1.15,3,0,cvSize(25,15)) for e in eyes: cvRectangle(image, cvPoint( int(e.x), int(e.y)), cvPoint(int(e.x + e.width), int(e.y + e.height)), CV_RGB(0, 255, 0), 1, 8, 0) return image; When I run this code, It draws rectangles irrelevant places. I thought, eye_region coordinates are wrong, and tried some coordinates, but it didn't work. Any idea ? Note :Face detection method works very well, and it's code is same with the eye detection method.

    Read the article

  • WPF DataGrid: How to get Converter

    - by Nike
    I create DataGrid Columns with Binding (where i is a Int value): dataGrid.Columns.Add(new DataGridTextColumn { Header = i.ToString(), Binding = CreateBinding(i), }); private Binding CreateBinding(int num) { Binding bind = new Binding(string.Format("[{0}]", num)); bind.Converter = new CellValueConverter(); return bind; } In the CreateBinding method I have an access to bind.Converter property. I need to call Converter.Convert() method in some handler, but there is no Converter property when I try to access it: (dataGrid.Columns[clm] as DataGridTextColumn).Binding."no Converter property!" How can I get my CellValueConverter which was created for particular Column?

    Read the article

  • Disable script debugging in IWebBrowser2 OLE control? C++

    - by flyout
    I have a IWebBrowser2 I use to visit some webpages with .Navigate() When the page has a js error I got a warning box for "Syntax error", so I used .put_Silent(TRUE). And now I get a warning for "VS Just-In-Time Debugger: Unhandled exception" instead How can I disable all the script error warnings (including JIT debugger) from my code (i mean without modifying the real IE settings)?

    Read the article

  • Javascript, Can I "redirect" user in onbeforeunload? If cant, how to...

    - by kanayaki
    Is it possible to redirect to another page when userclose browser? Attempts: I tried onunload, does not work window.onunload = function redirect(){...} I also tried another method, it does not work as well: window.onbeforeunload = redirect(){...} <body onbeforeunload="return false; redirecty()"> The 3rd method, i want to cancel the onbeforeunload (means delay closing the browser), the I call the redirect function, window.confirm, if yes redirect, if no then close the browser. But it does not work as well. Is there any other way?? Run out of ideas... -- Prompt to let user select whether to redirect to new page when he/she close the browser -- This is the first time, I could not get best answer in stackoverflow :(

    Read the article

  • NoHostAvailableException With Cassandra & DataStax Java Driver If Large ResultSet

    - by hughj
    The setup: 2-node Cassandra 1.2.6 cluster replicas=2 very large CQL3 table with no secondary index Rowkey is a UUID.randomUUID().toString() read consistency set to ONE Using DataStax java driver 1.0 The request: Attempting to do a table scan by "SELECT some-col from schema.table LIMIT nnn;" The fail: Once I go beyond a certain nnn LIMIT, I start to get NoHostAvailableExceptions from the driver. It reads like this: com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s) tried for query failed (tried: /10.181.13.239 ([/10.181.13.239] Unexpected exception triggered)) at com.datastax.driver.core.exceptions.NoHostAvailableException.copy(NoHostAvailableException.java:64) at com.datastax.driver.core.ResultSetFuture.extractCauseFromExecutionException(ResultSetFuture.java:214) at com.datastax.driver.core.ResultSetFuture.getUninterruptibly(ResultSetFuture.java:169) at com.jpmc.es.rtm.storage.impl.EventExtract.main(EventExtract.java:36) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:601) at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120) Caused by: com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s) tried for query failed (tried: /10.181.13.239 ([/10.181.13.239] Unexpected exception triggered)) at com.datastax.driver.core.RequestHandler.sendRequest(RequestHandler.java:98) at com.datastax.driver.core.RequestHandler$1.run(RequestHandler.java:165) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) Given: This is probably not the most enlightened thing to do to a large table with millions of rows, but this is how I learn what not to do, so I would really appreciate someone who could volunteer how this kind of error can be debugged. For example, when this happens, there are no indications that the nodes in the cluster ever had an issue with the request (there is nothing in the logs on either node that indicate any timeout or failure). Also, I enabled the trace on the driver, which gives you some nice autotrace (ala Oracle) info as long as the query succeeds. But in this case, the driver blows a NoHostAvailableException and no ExecutionInfo is available, so tracing has not provided any benefit in this case. I also find it interesting that this does not seem to be recorded as a timeout (my JMX consoles tell me no timeouts have occurred). So, I am left not understanding WHERE the failure is actually occurring. I am left with the idea that it is the driver that is having a problem, but I don't know how to debug it (and I would really like to). I have read several posts from folks that state that query'g for resultSets 10000 rows is probably not a good idea, and I am willing to accept this, but I would like to understand what is causing the exception and where the exception is happening. FWIW, I also tried bumping the timeout properties in the cassandra.yaml, but this made no difference whatsoever. I welcome any suggestions, anecdotes, insults, or monetary contributions for my registration in the house of moron-developers. Regards!!

    Read the article

  • Where Googlebot starts crawling?

    - by Nirmal
    Say if I register a domain and have developed it into a complete website. From where and how Googlebot knows that the new domain is up? Does it always start with the domain registry? If it starts with the registry, does that mean that anyone can have complete access to the registry's database? Thanks for any insight.

    Read the article

  • ASP.NET MVC TDD with LINQ and SQL database

    - by dean nolan
    I am trying to start a new MVC project with tests and I thought the best way to go would have 2 databases. 1 for testing against and 1 for when I run the app and use it (also test really as it's not production yet). For the test database I was thinking of putting create table scripts and fill data scripts within the test setup method and then deleting all this in the tear down method. I am going to be using Linq to SQL though and I don't think that will allow me to do this? Will I have to just go the ADO route if I want to do it this way? Or should I just use a mock object and store data as an array or something?. Any tips on best practices? How did Jeff go about doing this for StackOveflow?

    Read the article

  • MVC - Calling Controller Methods

    - by JT703
    Hello, My application is following the MVC design pattern. The problem I keep running into is needing to call methods inside a Controller class from outside that Controller class (ex. A View class wants to call a Controller method, or a Manager class wants to call a Controller method). Is calling Controller methods in this way allowed in MVC? If it's allowed, what's the proper way to do it? According to the version of MVC that I am following (there seems to be so many different versions out there), the View knows of the Model, and the Controller knows of the View. Doing it this way, I can't access the controller. Here's the best site I've found and the one describing the version of MVC I'm following: http://leepoint.net/notes-java/GUI/structure/40mvc.html. The Main Program code block really shows how this works. Thanks for any answers.

    Read the article

  • jquery ui autocomplete database

    - by user343925
    Hello, I'd like to use jQuery UI autocomplete in order to load a list from my database but I don't know wich method I should use to do so. I tried to use the "Remote datasource" method [url]http://jqueryui.com/demos/autocomplete/#remote[/url], but it obviously doesn't work. I have the following code : js: $(function() { $("#client").autocomplete({ source: "nom.php", minLength: 2, select: function(event, ui) { alert(ui); } }); }); html : <label for="client">Client</label> <input name="client" id="client" class="ui-autocomplete ui-widget-content ui-corner-all" /> php: $query = "SELECT nom from personne"; $result = mysql_query($query, $db); while($row = mysql_fetch_assoc($result)) { foreach($row as $val) $tab[] = $val; } print json_encode($tab); It does work with ["hello","test1","test2"] instead of the url but I need to load datas form database so pls tell me how I should do. thank you

    Read the article

  • How do those bitmasks actually work?

    - by mystify
    For example, this method from NSCalendar takes a bitmask: - (NSDate *)dateByAddingComponents:(NSDateComponents *)comps toDate:(NSDate *)date options:(NSUInteger)opts So options can be like: NSUInteger options = kCFCalendarUnitYear; or like: NSUInteger options = kCFCalendarUnitYear | kCFCalendarUnitMonth | kCFCalendarUnitDay; What I don't get is, how is this actually done? I mean: How can they pull out those values which are merged into options? If I wanted to program something like this, that can take a bitmask, how would that look?

    Read the article

  • http://java.sun.com/j2se/1.4.2/docs/api/org/w3c/dom/Document.html#getDoctype()

    - by Tom Brito
    The Document class have a getDoctype method but doesn't have a setDoctype. The documentation says: The DOM Level 2 does not support editing the Document Type Declaration. docType cannot be altered in any way, including through the use of methods inherited from the Node interface, such as insertNode or removeNode. and in my project I need to generate xml files with my specified doctypes. I've tryied to create my own DefaultNode, but it throws "DOMException: Method not supported" for the setters. Any idea?

    Read the article

  • Objective C, Core Data issue

    - by Jaime Rae
    I'm following a tutorial in "More iPhone 3 Development. In the code, they have a line: NSManagedObjectContext *managedObjectContext = appDelegate.managedObjectContext; I get an error: "accessing unknown 'managedObjectContext' getter method" on that line. I've downloaded his sample code and his program runs fine with that line of code. I've tried rewriting the code and I've even copied and pasted his code into my program, but I still get the error. I am using the newest SDK, and I'm wondering if something might have changed so this getter method doesn't work anymore, but I do not get any warning about deprecation. Does anyone know what is going on, or better yet, a better way to write this line and not get the error. Thanks LadyDev

    Read the article

  • How to map hash keys to methods for an encapsulated Ruby class (tableless model)?

    - by user502052
    I am using Ruby on Rails 3 and I am tryng to map a hash (key, value pairs) to an encapsulated Ruby class (tableless model) making the hash key as a class method that returns the value. In the model file I have class Users::Account #< ActiveRecord::Base def initialize(attributes = {}) @id = attributes[:id] @firstname = attributes[:firstname] @lastname = attributes[:lastname] end end def self.to_model(account) JSON.parse(account) end My hash is hash = {\"id\":2,\"firstname\":\"Name_test\",\"lastname\":\"Surname_test\"} I can make account = Users::Account.to_model(hash) that returns (debugging) --- id: 2 firstname: Name_test lastname: Surname_test That works, but if I do account.id I get this error NoMethodError in Users/accountsController#new undefined method `id' for #<Hash:0x00000104cda410> I think because <Hash:0x00000104cda410> is an hash (!) and not the class itself. Also I think that doing account = Users::Account.to_model(hash) is not the right approach. What is wrong? How can I "map" those hash keys to class methods?

    Read the article

  • How to add 1 to the value of a column of an existing row in mysql

    - by mithun1538
    Hello everyone, I have a table called pollData. It will always contain only 1 row. It has columns option1, option2, option3, option4, option5 each of type int. In the beginning, these columns have 0 as their value. How do I add 1 to any column, say option2? I mean do i retrieve the value of that column first, perform addition, and store back, or is there any auto increment function?

    Read the article

  • Some instruction needed for PHP OOPS concepts.

    - by Avinash
    Hi, I need to clear some OOPS concepts in PHP. 1) Which is faster $this-method(); or self:method(); 2) I know the concept of static keyword but can you please post the actual Use of it. Since it can not be accessed by the instance, but is there ant benefit for that? 3) what is factory? How can i use it? 4) What is singleton? How can i use that? 5) What is late static binding? http://www.php.net/manual/en/oop5.intro.php I have gone through below link but I am not getting clear with it. Thanks Avinash

    Read the article

  • Why is this class re-initialized every time?

    - by pinnacler
    I have 4 files and the code 'works' as expected. I try to clean everything up, place code into functions, etc... and everything looks fine... and it doesn't work. Can somebody please explain why MatLab is so quirky... or am I just stupid? Normally, I type terminator = simulation(100,20,0,0,0,1); terminator.animate(); and it should produce a map of trees with the terminator walking around in a forest. Everything rotates to his perspective. When I break it into functions... everything ceases to work. I really only changed a few lines of code, shown in comments. Code that works: classdef simulation properties landmarks robot end methods function obj = simulation(mapSize, trees, x,y,heading,velocity) obj.landmarks = landmarks(mapSize, trees); obj.robot = robot(x,y,heading,velocity); end function animate(obj) %Setup Plots fig=figure; xlabel('meters'), ylabel('meters') set(fig, 'name', 'Phil''s AWESOME 80''s Robot Simulator') xymax = obj.landmarks.mapSize*3; xymin = -(obj.landmarks.mapSize*3); l=scatter([0],[0],'bo'); axis([xymin xymax xymin xymax]); obj.landmarks.apparentPositions %Simulation Loop THIS WAS ORGANIZED for n = 1:720, %Calculate and Set Heading/Location obj.robot.headingChange = navigate(n); %Update Position obj.robot.heading = obj.robot.heading + obj.robot.headingChange; obj.landmarks.heading = obj.robot.heading; y = cosd(obj.robot.heading); x = sind(obj.robot.heading); obj.robot.x = obj.robot.x + (x*obj.robot.velocity); obj.robot.y = obj.robot.y + (y*obj.robot.velocity); obj.landmarks.x = obj.robot.x; obj.landmarks.y = obj.robot.y; %Animate set(l,'XData',obj.landmarks.apparentPositions(:,1),'YData',obj.landmarks.apparentPositions(:,2)); rectangle('Position',[-2,-2,4,4]); drawnow end end end end ----------- classdef landmarks properties fixedPositions %# positions in a fixed coordinate system. [ x, y ] mapSize = 10; %Map Size. Value is side of square x=0; y=0; heading=0; headingChange=0; end properties (Dependent) apparentPositions end methods function obj = landmarks(mapSize, numberOfTrees) obj.mapSize = mapSize; obj.fixedPositions = obj.mapSize * rand([numberOfTrees, 2]) .* sign(rand([numberOfTrees, 2]) - 0.5); end function apparent = get.apparentPositions(obj) %-STILL ROTATES AROUND ORIGINAL ORIGIN currentPosition = [obj.x ; obj.y]; apparent = bsxfun(@minus,(obj.fixedPositions)',currentPosition)'; apparent = ([cosd(obj.heading) -sind(obj.heading) ; sind(obj.heading) cosd(obj.heading)] * (apparent)')'; end end end ---------- classdef robot properties x y heading velocity headingChange end methods function obj = robot(x,y,heading,velocity) obj.x = x; obj.y = y; obj.heading = heading; obj.velocity = velocity; end end end ---------- function headingChange = navigate(n) %steeringChange = 5 * rand(1) * sign(rand(1) - 0.5); Most chaotic shit %Draw an S if n <270 headingChange=1; elseif n<540 headingChange=-1; elseif n<720 headingChange=1; else headingChange=1; end end Code that does not work... classdef simulation properties landmarks robot end methods function obj = simulation(mapSize, trees, x,y,heading,velocity) obj.landmarks = landmarks(mapSize, trees); obj.robot = robot(x,y,heading,velocity); end function animate(obj) %Setup Plots fig=figure; xlabel('meters'), ylabel('meters') set(fig, 'name', 'Phil''s AWESOME 80''s Robot Simulator') xymax = obj.landmarks.mapSize*3; xymin = -(obj.landmarks.mapSize*3); l=scatter([0],[0],'bo'); axis([xymin xymax xymin xymax]); obj.landmarks.apparentPositions %Simulation Loop for n = 1:720, %Calculate and Set Heading/Location %Update Position headingChange = navigate(n); obj.robot.updatePosition(headingChange); obj.landmarks.updatePerspective(obj.robot.heading, obj.robot.x, obj.robot.y); %Animate set(l,'XData',obj.landmarks.apparentPositions(:,1),'YData',obj.landmarks.apparentPositions(:,2)); rectangle('Position',[-2,-2,4,4]); drawnow end end end end ----------------- classdef landmarks properties fixedPositions; %# positions in a fixed coordinate system. [ x, y ] mapSize; %Map Size. Value is side of square x; y; heading; headingChange; end properties (Dependent) apparentPositions end methods function obj = createLandmarks(mapSize, numberOfTrees) obj.mapSize = mapSize; obj.fixedPositions = obj.mapSize * rand([numberOfTrees, 2]) .* sign(rand([numberOfTrees, 2]) - 0.5); end function apparent = get.apparentPositions(obj) %-STILL ROTATES AROUND ORIGINAL ORIGIN currentPosition = [obj.x ; obj.y]; apparent = bsxfun(@minus,(obj.fixedPositions)',currentPosition)'; apparent = ([cosd(obj.heading) -sind(obj.heading) ; sind(obj.heading) cosd(obj.heading)] * (apparent)')'; end function updatePerspective(obj,tempHeading,tempX,tempY) obj.heading = tempHeading; obj.x = tempX; obj.y = tempY; end end end ----------------- classdef robot properties x y heading velocity end methods function obj = robot(x,y,heading,velocity) obj.x = x; obj.y = y; obj.heading = heading; obj.velocity = velocity; end function updatePosition(obj,headingChange) obj.heading = obj.heading + headingChange; tempy = cosd(obj.heading); tempx = sind(obj.heading); obj.x = obj.x + (tempx*obj.velocity); obj.y = obj.y + (tempy*obj.velocity); end end end The navigate function is the same... I would appreciate any help as to why things aren't working. All I did was take the code from the first section from under comment: %Simulation Loop THIS WAS ORGANIZED and break it into 2 functions. One in robot and one in landmarks. Is a new instance created every time because it's constantly printing the same heading for this line int he robot class obj.heading = obj.heading + headingChange;

    Read the article

  • uploadify changing scriptData

    - by kusanagi
    when i call uploadifySettings("scriptData", { 'description': description }); it mean that param description is set one time after click button upload, how can i set param description on each file that uploads ? for example i want to upload 10 files so i can change param description 10 times

    Read the article

  • Boost::Asio : io_service.run() vs poll() or how do I integrate boost::asio in mainloop

    - by user300713
    Hi, I am currently trying to use boost::asio for some simple tcp networking for the first time, and I allready came across something I am not really sure how to deal with. As far as I understand io_service.run() method is basically a loop which runs until there is nothing more left to do, which means it will run until I release my little server object. Since I allready got some sort of mainloop set up, I would rather like tp update the networking loop manually from there just for the sake of simplicity, and I think io_service.poll() would do what I want, sort of like this: void myApplication::update() { myIoService.poll(); //do other stuff } This seems to work, but I am still wondering if there is a drawback from this method since that does not seem to be the common way to deal with boost::asios io services. Is this a valid approach or should I rather use io_service.run() in a non blocking extra thread?

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 493 494 495 496 497 498 499 500 501 502 503 504  | Next Page >