Search Results

Search found 6805 results on 273 pages for 'variables'.

Page 225/273 | < Previous Page | 221 222 223 224 225 226 227 228 229 230 231 232  | Next Page >

• C++ ofstream cannot write to file....

  - by user69514

  Hey I am trying to write some numbers to a file, but when I open the file it is empty. Can you help me out here? Thanks. /** main function **/ int main(){ /** variables **/ RandGen* random_generator = new RandGen; int random_numbers; string file_name; /** ask user for quantity of random number to produce **/ cout << "How many random number would you like to create?" << endl; cin >> random_numbers; /** ask user for the name of the file to store the numbers **/ cout << "Enter name of file to store random number" << endl; cin >> file_name; /** now create array to store the number **/ int random_array [random_numbers]; /** file the array with random integers **/ for(int i=0; i<random_numbers; i++){ random_array[i] = random_generator -> randInt(-20, 20); cout << random_array[i] << endl; } /** open file and write contents of random array **/ const char* file = file_name.c_str(); ofstream File(file); /** write contents to the file **/ for(int i=0; i<random_numbers; i++){ File << random_array[i] << endl; } /** close the file **/ File.close(); return 0; /** END OF PROGRAM **/ }

  Read the article

• Is it possible to prevent out-of-order execution by using single volatile

  - by Yan Cheng CHEOK

  By referring article, it is using a pair of volatile to prevent out-of-order execution. I was wondering, is it possible to prevent it using single volatile? void fun_by_thread_1() { this.isNuclearFactory = true; this.factory = new NuclearFactory(); } void fun_by_thread_2() { Factory _factory = this.factory; if (this.isNuclearFactory) { // Do not operate nuclear factory!!! return; } // If out-of-order execution happens, _factory might // be NuclearFactory instance. _factory.operate(); } Factory factory = new FoodFactory(); volatile boolean isNuclearFactory = false; The reason I ask, is because I have a single guard flag (similar to isNuclearFactory flag), to guard against multiple variables (similar to many Factory). I do not wish to mark all the Factory as volatile. Or, shall I fall into the following solution? void fun_by_thread_1() { try { writer.lock(); this.isNuclearFactory = true; this.factory = new NuclearFactory(); } finally { writer.unlock(); } } void fun_by_thread_2() { try { reader.lock(); Factory _factory = this.factory; if (this.isNuclearFactory) { // Do not operate nuclear factory!!! return; } } finally { reader.unlock(); } _factory.operate(); } Factory factory = new FoodFactory(); boolean isNuclearFactory = false; P/S: I know instanceof. Factory is just an example to demonstrate of out-of-order problem.

  Read the article

• Py_INCREF/DECREF: When

  - by Izz ad-Din Ruhulessin

  Is one correct in stating the following: If a Python object is created in a C function, but the function doesn't return it, no INCREF is needed, but a DECREF is. [false]If the function does return it, you do need to INCREF, in the function that receives the return value.[/false] When assigning C typed variables as attributes, like double, int etc., to the Python object, no INCREF or DECREF is needed. Assigning Python objects as attributes to your other Python objects goes like this: PyObject *foo; foo = bar // A Python object tmp = self->foo; Py_INCREF(foo); self->foo = foo; Py_XDECREF(tmp); //taken from the manual, but it is unclear if this works in every situation EDIT: -- can I safely use this in every situation? (haven't run into one where it caused me problems) dealloc of a Python object needs to DECREF for every other Python object that it has as an attribute, but not for attributes that are C types. Edit With 'C type as an attribute I mean bar and baz: typedef struct { PyObject_HEAD PyObject *foo; int bar; double baz; } FooBarBaz;

  Read the article

• Highlighting correctly in an emacs major mode

  - by Paul Nathan

  Hi, I am developing an emacs major mode for a language (aka mydsl). However, using the techniques on xahlee's site doesn't seem to be working for some reason (possibly older emacs dialect..) The key issues I am fighting with are (1) highlighting comments is not working and (2), the use of regexp-opt lines is not working. I've reviewed the GNU manual and looked over cc-mode and elisp mode... those are significantly more complicated than I need. ;;;Standard # to newline comment ;;;Eventually should also have %% to %% multiline block comments (defun mydsl-comment-dwim (arg) "comment or uncomment" (interactive "*P") (require 'newcomment) (let ((deactivate-mark nil) (comment-start "#") (comment-end "") comment-dwim arg))) (defvar mydsl-events '("reservedword1" "reservedword2")) (defvar mydsl-keywords '("other-keyword" "another-keyword")) ;;Highlight various elements (setq mydsl-hilite '( ; stuff between " ("\"\\.\\*\\?" . font-lock-string-face) ; : , ; { } => @ $ = are all special elements (":\\|,\\|;\\|{\\|}\\|=>\\|@\\|$\\|=" . font-lock-keyword-face) ( ,(regexp-opt mydsl-keywords 'words) . font-lock-builtin-face) ( ,(regexp-opt mydsl-events 'words) . font-lock-constant-face) )) (defvar mydsl-tab-width nil "Width of a tab for MYDSL mode") (define-derived-mode mydsl-mode fundamental-mode "MYDSL mode is a major mode for editing MYDSL files" ;Recommended by manual (kill-all-local-variables) (setq mode-name "MYDSL script") (setq font-lock-defaults '((mydsl-hilite))) (if (null mydsl-tab-width) (setq tab-width mydsl-tab-width) (setq tab-width default-tab-width) ) ;Comment definitions (define-key mydsl-mode-map [remap comment-dwim] 'mydsl-comment-dwim) (modify-syntax-entry ?# "< b" mydsl-mode-syntax-table) (modify-syntax-entry ?\n "> b" mydsl-mode-syntax-table) ;;A gnu-correct program will have some sort of hook call here. ) (provide 'mydsl-mode)

  Read the article

• Multiple ajax request and progress bar

  - by hunt

  Hi, In a following piece of code i am create a progress bar and showing its progress as the ajax request get processed. i am faking the progress shown here just by adding 5 in to cnt counter variable after that i made a check when counter reach to 90. at this point if the request is not executed successfully then i will pause/disable the progress bar and whenever response come i will complete the whole progress bar with 100. now the problem is i want to add multiple progress bar as i am firing multiple ajax request. so following is the code to implement only for one request and one progress bar but i want it for more than one. as global variables are used over here for checking response and timer id so i don't know how well i can handle it for multiple request var cnt=0; var res=null; function getProgress(data){ res=data; } var i =0; $('#start').click(function(){ i = setInterval(function() { if(res!=null) { clearInterval(i); $("#pb1").progressbar( "option", "value", cnt=cnt+100 ); } var value = $("#pb1").progressbar("option", "value"); if(value >=90 && res==null){ $("#pb1").progressbar("option", "disable"); } else{ $("#pb1").progressbar( "option", "value", cnt=cnt+5 ); } },2500); $.ajax({ url: 'http://localhost/beta/demo.php', success: getProgress }); }); $("#pb1").progressbar({ value: 0 , change: function(event, ui) { if(res!=null) clearInterval(i); } });

  Read the article

• Change classloader

  - by Chris

  I'm trying to switch the class loader at runtime: public class Test { public static void main(String[] args) throws Exception { final InjectingClassLoader classLoader = new InjectingClassLoader(); Thread.currentThread().setContextClassLoader(classLoader); Thread thread = new Thread("test") { public void run() { System.out.println("running..."); // approach 1 ClassLoader cl = TestProxy.class.getClassLoader(); try { Class c = classLoader.loadClass("classloader.TestProxy"); Object o = c.newInstance(); c.getMethod("test", new Class[] {}).invoke(o); } catch (Exception e) { e.printStackTrace(); } // approach 2 new TestProxy().test(); }; }; thread.setContextClassLoader(classLoader); thread.start(); } } and: public class TestProxy { public void test() { ClassLoader tcl = Thread.currentThread().getContextClassLoader(); ClassLoader ccl = ClassToLoad.class.getClassLoader(); ClassToLoad classToLoad = new ClassToLoad(); } } (it is not relevant what the InjectingClassLoader is) I'd like to make the result of "approach 1" and "approach 2" exactly same, but it looks like thread.setContextClassLoader(classLoader) does nothing and the "approach 2" always uses the system classloader (can be determined by comparing tcl and ccl variables while debugging). Is it possible to make all classes loaded by new thread use given classloader?

  Read the article

• Interface vs Abstract Class (general OO)

  - by Kave

  Hi, I have had recently two telephone interviews where I've been asked about the differences between an Interface and an Abstract class. I have explained every aspect of them I could think of, but it seems they are waiting for me to mention something specific, and I dont know what it is. From my experience I think the following is true, if i am missing a major point please let me know: Interface: Every single Method declared in an Interface will have to be implemented in the subclass. Only Events, Delegates, Properties (C#) and Methods can exist in a Interface. A class can implement multiple Interfaces. Abstract Class Only Abstract methods have to be implemented by the subclass. An Abstract class can have normal methods with implementations. Abstract class can also have class variables beside Events, Delegates, Properties and Methods. A class can only implement one abstract class only due non-existence of Multi-inheritance in C#. 1) After all that the interviewer came up with the question What if you had an Abstract class with only abstract methods, how would that be different from an interface? I didnt know the answer but I think its the inheritance as mentioned above right? 2) An another interviewer asked me what if you had a Public variable inside the interface, how would that be different than in Abstract Class? I insisted you can't have a public variable inside an interface. I didn't know what he wanted to hear but he wasn't satisfied either. Many Thanks for clarification, Kave See Also: When to use an interface instead of an abstract class and vice versa Interfaces vs. Abstract Classes How do you decide between using an Abstract Class and an Interface?

  Read the article

• Using same onmouseover function for multiple objects

  - by phpscriptcoder

  I'm creating a building game in JavaScript and PHP that involves a grid. Each square in the grid is a div, with an own onmouseover and onmousedown function: for(x=0; x < width; x++) { for(y=0; y < height; y++) { var div = document.createElement("div"); //... div.onmouseclick = function() {blockClick(x, y)} div.onmouseover = function() {blockMouseover(x, y)} game.appendChild(div); } } But, all of the squares seem to have the x and y of the last square that was added. I can sort of see why this is happening - it is making a pointer to x and y instead of cloning the variables - but how could I fix it? I even tried for(x=0; x < width; x++) { for(y=0; y < height; y++) { var div = document.createElement("div"); var myX = x; var myY = y; div.onmouseclick = function() {blockClick(myX, myY)} div.onmouseover = function() {blockMouseover(myX, myY)} game.appendChild(div); } } with the same result. I was using div.setAttribute("onmouseover", ...) which worked in Firefox, but not IE. Thanks!

  Read the article

• How do you refactor a large messy codebase?

  - by Ricket

  I have a big mess of code. Admittedly, I wrote it myself - a year ago. It's not well commented but it's not very complicated either, so I can understand it -- just not well enough to know where to start as far as refactoring it. I violated every rule that I have read about over the past year. There are classes with multiple responsibilities, there are indirect accesses (I forget the technical term - something like foo.bar.doSomething()), and like I said it is not well commented. On top of that, it's the beginnings of a game, so the graphics is coupled with the data, or the places where I tried to decouple graphics and data, I made the data public in order for the graphics to be able to access the data it needs... It's a huge mess! Where do I start? How would you start on something like this? My current approach is to take variables and switch them to private and then refactor the pieces that break, but that doesn't seem to be enough. Please suggest other strategies for wading through this mess and turning it into something clean so that I can continue where I left off!

  Read the article

• FFMEPG permission problem, is there any alternative solution instead of FFMPEG?

  - by caglaror

  We have some kind of permenant permission problem on FFMPEG.exe to write JPEG file on to HDD. We are using IIS and try all permission methods to ffmepg.exe, its including folder,folders, cmd.exe and any executable file, related folder, file. Also we tried many many command examples. But never went beyond the "permission denied" error messages. We give up. Do you know another alternative solution to pick images from flv, f4v movie files? Or %100 quaranteed method to achive this permission control on IIS? Thank you. ---last code we try variables etc. aren't shown here. jpegYapKomutu = videoEditorKlasoru &"\ffmpeg.exe -i " & videoEditorKlasoru & "\deneme.flv" &" -s 480×360 -ss 00:00:"&saniyesi&" -vframes 1 -f mjpeg "& "C:\Webhome\normworks\caglarorhan\deneme.jpg" WScript.Run "%COMSPEC% /C dir" & jpegYapKomutu

  Read the article

• Regex: match a non nested code block

  - by Sylvanas Garde

  I am currently writing a small texteditor. With this texteditor users are able to create small scripts for a very simple scripting engine. For a better overview I want to highlight codeblocks with the same command like GoTo(x,y) or Draw(x,y). To achieve this I want to use Regular Expresions (I am already using it to highlight other things like variables) Here is my Expression (I know it's very ugly): /(?<!GoTo|Draw|Example)(^(?:GoTo|Draw|Example)\(.+\)*?$)+(?!GoTo|Draw|Example)/gm It matches the following: lala GoTo(5656) -> MATCH 1 sdsd GoTo(sdsd) --comment -> MATCH 2 GoTo(23329); -> MATCH 3 Test() GoTo(12) -> MATCH 4 LALA Draw(23) -> MATCH 5 Draw(24) -> MATCH 6 Draw(25) -> MATCH 7 But what I want to achieve is, that the complete "blocks" of the same command are matched. In this case Match 2 & 4 and Match 5 & 6 & 7 should be one match. Tested with http://regex101.com/, the programming lanuage is vb.net. Any advise would be very useful, Thanks in advance!

  Read the article

• Effective Method to Manage and Search Through 100,000+ Objects Instantly? (C#)

  - by Kirk

  I'm writing a media player for enthusiasts with large collections (over 100,000 tracks) and one of my main goals is speed in search. I would like to allow the user to perform a Google-esque search of their entire music collection based on these factors: Song Path and File Name Items in ID3 Tag (Title, Artist, Album, etc.) Lyrics What is the best way for me to store this data and search through it? Currently I am storing each track in an object and iterating over an array of these objects checking each of their variables for string matches based on given search text. I've run into problems though where my search is not effective because it is always a phrase search and I'm not sure how to make it more fuzzy. Would an internal DB like SQLlite be faster than this? Any ideas on how I should structure this system? I also need playlist persistence, so that when they close the app and open the app their same playlist loads immediately. How should I store the playlist information so it can load quickly when the application starts? Currently I am JSON encoding the entire playlist, storing it in a text file, and reading it into the ListView at runtime, but it is getting sluggish over 20,000 tracks. Thanks!

  Read the article

• Struts2 Converting Enum Array fills array with single null value

  - by Kyle Partridge

  For a simple action class with these member variables: ... private TestConverterEnum test; private TestConverterEnum[] tests; private List<TestConverterEnum> tList; ... And a simple enum: public enum TestConverterEnum { A, B, C; } Using the default struts2 enum conversion, when I send the request like so: TestConterter.action?test=&tests=&tList=&b=asdf For test I get a null value, which is expected. For the Array and List, however, I get and Array (or list) with one null element. Is this what is expected? Is there a way to prevent this. We recently upgraded our struts2 version, and we had our own converters, which also don't work in this case, so I was hoping to use the default conversion method. We already have code that is validating these arrays for null and length, and I don't want to have to add another condition to these branches. Is there a way to prevent this bevavior?

  Read the article

• InvalidCastException when getting Text from a Label referenced by dynamicaly built String, Fix?

  - by Chris

  NET Version: 3.5 Ok, I recieve an error (System.InvalidCastException was unhandled. Message="Unable to cast object of type 'System.Windows.Forms.Control[]' to type 'System.Windows.Forms.Label'.") when trying to get Text from a Label referenced by a dynamicly built string. Here's my situation; I have an array of 250 labels named l1 - l250. What I want to do is loop through them using this while statement: int c = 1; while (c < 251) { string k = "l" + c.ToString(); //dynamic name of Control(Label) object ka = Controls.Find(k, true); string ct = ((Label)ka).Text; //<<Error Occurs Here build = build + ct; c++; } and get the text value of each to build a string named build. I don't get any build errors, just this while debuging. While debuging I can go down to view my local variables. When looking through these, I can view the contents of object ka; it does contain the correct Text value of the correct Label I want to "access". I just don't understand how to get there. The text value is listed under "[0]" which is the only subcatagory for "ka".

  Read the article

• Is there really such a thing as a char or short in modern programming?

  - by Dean P

  Howdy all, I've been learning to program for a Mac over the past few months (I have experience in other languages). Obviously that has meant learning the Objective C language and thus the plainer C it is predicated on. So I have stumbles on this quote, which refers to the C/C++ language in general, not just the Mac platform. With C and C++ prefer use of int over char and short. The main reason behind this is that C and C++ perform arithmetic operations and parameter passing at integer level, If you have an integer value that can fit in a byte, you should still consider using an int to hold the number. If you use a char, the compiler will first convert the values into integer, perform the operations and then convert back the result to char. So my question, is this the case in the Mac Desktop and IPhone OS environments? I understand when talking about theses environments we're actually talking about 3-4 different architectures (PPC, i386, Arm and the A4 Arm variant) so there may not be a single answer. Nevertheless does the general principle hold that in modern 32 bit / 64 bit systems using 1-2 byte variables that don't align with the machine's natural 4 byte words doesn't provide much of the efficiency we may expect. For instance, a plain old C-Array of 100,000 chars is smaller than the same 100,000 ints by a factor of four, but if during an enumeration, reading out each index involves a cast/boxing/unboxing of sorts, will we see overall lower 'performance' despite the saved memory overhead?

  Read the article

• Adding string items to a list of type Person C#

  - by user1862808

  Im makeing a simple registration application and I have an assignment to learn more about lists. I have an assignment that says that i am to create a class called Persons and in that class set the values from the text fields in variables and add this to a list of type Person. So far: in the Person class: string strSocialSecurityNumber = string.Empty;//---( This will not be used now.) string strFirstName = string.Empty; string strLastName = string.Empty; string strFullName = string.Empty; string strAge = string.Empty; string strAll = string.Empty; int intAge = 0; List<Person> lstPerson = new List<Person>(); public void SetValues(string FirstName, string LastName, int Age) { strFirstName = FirstName; strLastName = LastName; strFullName = strFirstName + " " + strLastName; intAge = Age; strAge = Convert.ToString(intAge); strAll = strAge + " " + strFullName; } public List<Person> Person() { lstPerson.Add(strAll); return lstPerson; } Error message: "can not convert from string to Person" The assignment says that the list is to be of the type Person so i am suppose to add strings to it and ive looked how to do this but I dont know how. I have seen that there are options like "ConvertAll" But im not sure if I am allowed to use it since the list should be of type Person. Thank you!

  Read the article

• memcache is not storing data accross requests

  - by morpheous

  I am new to using memcache, so I may be doing something wrong. I have written a wrapper class around memcache. The wrapper class has only static methods, so is a quasi singleton. The class looks something like this: class myCache { private static $memcache = null; private static $initialized = false; public static function init() { if (self::$initialized) return; self::$memcache = new Memcache(); if (self::configure()) //connects to daemon { self::store('foo', 'bar'); } else throw ConnectionError('I barfed'); } public static function store($key, $data, $flag=MEMCACHE_COMPRESSED, $timeout=86400) { if (self::$memcache->get($key)!== false) return self::$memcache->replace($key, $data, $flag, $timeout); return self::$memcache->set($key, $data, $flag, $timeout); } public static function fetch($key) { return self::$memcache->get($key); } } //in my index.php file, I use the class like this require_once('myCache.php'); myCache::init(); echo 'Stored value is: '. myCache::fetch('foo'); The problem is that the myCache::init() method is being executed in full everytime a page is requested. I then remembered that static variables do not maintain state accross page requests. So I decided instead, to store the flag that indicates whether the server contains the start up data (for our purposes, the variable 'foo', with value 'bar') in memcache itself. Once the status flag is stored in memcache itself, It solves the problem of the initialisation data being loaded for every page request (which quite frankly, defeats the purpose of memcache). However, having solved that problem, when I come to fetch the data in memcache, it is empty. I dont understand whats going on. Can anyone clarify how I can store my data once and retrieve it accross page requests? BTW, (just to clarify), the get/set is working correctly, and if I allow memcache to load the initialisation data for each page request, (which is silly), then the data is available in memcache.

  Read the article

• help me improve my sse yuv to rgb ssse3 code

  - by David McPaul

  Hello, I am looking to optimise some sse code I wrote for converting yuv to rgb (both planar and packed yuv functions). i am using SSSE3 at the moment but if there are useful functions from later sse versions thats ok. I am mainly interested in how I would work out processor stalls and the like. Anyone know of any tools that do static analysis of sse code? ; ; Copyright (C) 2009-2010 David McPaul ; ; All rights reserved. Distributed under the terms of the MIT License. ; ; A rather unoptimised set of ssse3 yuv to rgb converters ; does 8 pixels per loop ; inputer: ; reads 128 bits of yuv 8 bit data and puts ; the y values converted to 16 bit in xmm0 ; the u values converted to 16 bit and duplicated into xmm1 ; the v values converted to 16 bit and duplicated into xmm2 ; conversion: ; does the yuv to rgb conversion using 16 bit integer and the ; results are placed into the following registers as 8 bit clamped values ; r values in xmm3 ; g values in xmm4 ; b values in xmm5 ; outputer: ; writes out the rgba pixels as 8 bit values with 0 for alpha ; xmm6 used for scratch ; xmm7 used for scratch %macro cglobal 1 global _%1 %define %1 _%1 align 16 %1: %endmacro ; conversion code %macro yuv2rgbsse2 0 ; u = u - 128 ; v = v - 128 ; r = y + v + v >> 2 + v >> 3 + v >> 5 ; g = y - (u >> 2 + u >> 4 + u >> 5) - (v >> 1 + v >> 3 + v >> 4 + v >> 5) ; b = y + u + u >> 1 + u >> 2 + u >> 6 ; subtract 16 from y movdqa xmm7, [Const16] ; loads a constant using data cache (slower on first fetch but then cached) psubsw xmm0,xmm7 ; y = y - 16 ; subtract 128 from u and v movdqa xmm7, [Const128] ; loads a constant using data cache (slower on first fetch but then cached) psubsw xmm1,xmm7 ; u = u - 128 psubsw xmm2,xmm7 ; v = v - 128 ; load r,b with y movdqa xmm3,xmm0 ; r = y pshufd xmm5,xmm0, 0xE4 ; b = y ; r = y + v + v >> 2 + v >> 3 + v >> 5 paddsw xmm3, xmm2 ; add v to r movdqa xmm7, xmm1 ; move u to scratch pshufd xmm6, xmm2, 0xE4 ; move v to scratch psraw xmm6,2 ; divide v by 4 paddsw xmm3, xmm6 ; and add to r psraw xmm6,1 ; divide v by 2 paddsw xmm3, xmm6 ; and add to r psraw xmm6,2 ; divide v by 4 paddsw xmm3, xmm6 ; and add to r ; b = y + u + u >> 1 + u >> 2 + u >> 6 paddsw xmm5, xmm1 ; add u to b psraw xmm7,1 ; divide u by 2 paddsw xmm5, xmm7 ; and add to b psraw xmm7,1 ; divide u by 2 paddsw xmm5, xmm7 ; and add to b psraw xmm7,4 ; divide u by 32 paddsw xmm5, xmm7 ; and add to b ; g = y - u >> 2 - u >> 4 - u >> 5 - v >> 1 - v >> 3 - v >> 4 - v >> 5 movdqa xmm7,xmm2 ; move v to scratch pshufd xmm6,xmm1, 0xE4 ; move u to scratch movdqa xmm4,xmm0 ; g = y psraw xmm6,2 ; divide u by 4 psubsw xmm4,xmm6 ; subtract from g psraw xmm6,2 ; divide u by 4 psubsw xmm4,xmm6 ; subtract from g psraw xmm6,1 ; divide u by 2 psubsw xmm4,xmm6 ; subtract from g psraw xmm7,1 ; divide v by 2 psubsw xmm4,xmm7 ; subtract from g psraw xmm7,2 ; divide v by 4 psubsw xmm4,xmm7 ; subtract from g psraw xmm7,1 ; divide v by 2 psubsw xmm4,xmm7 ; subtract from g psraw xmm7,1 ; divide v by 2 psubsw xmm4,xmm7 ; subtract from g %endmacro ; outputer %macro rgba32sse2output 0 ; clamp values pxor xmm7,xmm7 packuswb xmm3,xmm7 ; clamp to 0,255 and pack R to 8 bit per pixel packuswb xmm4,xmm7 ; clamp to 0,255 and pack G to 8 bit per pixel packuswb xmm5,xmm7 ; clamp to 0,255 and pack B to 8 bit per pixel ; convert to bgra32 packed punpcklbw xmm5,xmm4 ; bgbgbgbgbgbgbgbg movdqa xmm0, xmm5 ; save bg values punpcklbw xmm3,xmm7 ; r0r0r0r0r0r0r0r0 punpcklwd xmm5,xmm3 ; lower half bgr0bgr0bgr0bgr0 punpckhwd xmm0,xmm3 ; upper half bgr0bgr0bgr0bgr0 ; write to output ptr movntdq [edi], xmm5 ; output first 4 pixels bypassing cache movntdq [edi+16], xmm0 ; output second 4 pixels bypassing cache %endmacro SECTION .data align=16 Const16 dw 16 dw 16 dw 16 dw 16 dw 16 dw 16 dw 16 dw 16 Const128 dw 128 dw 128 dw 128 dw 128 dw 128 dw 128 dw 128 dw 128 UMask db 0x01 db 0x80 db 0x01 db 0x80 db 0x05 db 0x80 db 0x05 db 0x80 db 0x09 db 0x80 db 0x09 db 0x80 db 0x0d db 0x80 db 0x0d db 0x80 VMask db 0x03 db 0x80 db 0x03 db 0x80 db 0x07 db 0x80 db 0x07 db 0x80 db 0x0b db 0x80 db 0x0b db 0x80 db 0x0f db 0x80 db 0x0f db 0x80 YMask db 0x00 db 0x80 db 0x02 db 0x80 db 0x04 db 0x80 db 0x06 db 0x80 db 0x08 db 0x80 db 0x0a db 0x80 db 0x0c db 0x80 db 0x0e db 0x80 ; void Convert_YUV422_RGBA32_SSSE3(void *fromPtr, void *toPtr, int width) width equ ebp+16 toPtr equ ebp+12 fromPtr equ ebp+8 ; void Convert_YUV420P_RGBA32_SSSE3(void *fromYPtr, void *fromUPtr, void *fromVPtr, void *toPtr, int width) width1 equ ebp+24 toPtr1 equ ebp+20 fromVPtr equ ebp+16 fromUPtr equ ebp+12 fromYPtr equ ebp+8 SECTION .text align=16 cglobal Convert_YUV422_RGBA32_SSSE3 ; reserve variables push ebp mov ebp, esp push edi push esi push ecx mov esi, [fromPtr] mov edi, [toPtr] mov ecx, [width] ; loop width / 8 times shr ecx,3 test ecx,ecx jng ENDLOOP REPEATLOOP: ; loop over width / 8 ; YUV422 packed inputer movdqa xmm0, [esi] ; should have yuyv yuyv yuyv yuyv pshufd xmm1, xmm0, 0xE4 ; copy to xmm1 movdqa xmm2, xmm0 ; copy to xmm2 ; extract both y giving y0y0 pshufb xmm0, [YMask] ; extract u and duplicate so each u in yuyv becomes u0u0 pshufb xmm1, [UMask] ; extract v and duplicate so each v in yuyv becomes v0v0 pshufb xmm2, [VMask] yuv2rgbsse2 rgba32sse2output ; endloop add edi,32 add esi,16 sub ecx, 1 ; apparently sub is better than dec jnz REPEATLOOP ENDLOOP: ; Cleanup pop ecx pop esi pop edi mov esp, ebp pop ebp ret cglobal Convert_YUV420P_RGBA32_SSSE3 ; reserve variables push ebp mov ebp, esp push edi push esi push ecx push eax push ebx mov esi, [fromYPtr] mov eax, [fromUPtr] mov ebx, [fromVPtr] mov edi, [toPtr1] mov ecx, [width1] ; loop width / 8 times shr ecx,3 test ecx,ecx jng ENDLOOP1 REPEATLOOP1: ; loop over width / 8 ; YUV420 Planar inputer movq xmm0, [esi] ; fetch 8 y values (8 bit) yyyyyyyy00000000 movd xmm1, [eax] ; fetch 4 u values (8 bit) uuuu000000000000 movd xmm2, [ebx] ; fetch 4 v values (8 bit) vvvv000000000000 ; extract y pxor xmm7,xmm7 ; 00000000000000000000000000000000 punpcklbw xmm0,xmm7 ; interleave xmm7 into xmm0 y0y0y0y0y0y0y0y0 ; extract u and duplicate so each becomes 0u0u punpcklbw xmm1,xmm7 ; interleave xmm7 into xmm1 u0u0u0u000000000 punpcklwd xmm1,xmm7 ; interleave again u000u000u000u000 pshuflw xmm1,xmm1, 0xA0 ; copy u values pshufhw xmm1,xmm1, 0xA0 ; to get u0u0 ; extract v punpcklbw xmm2,xmm7 ; interleave xmm7 into xmm1 v0v0v0v000000000 punpcklwd xmm2,xmm7 ; interleave again v000v000v000v000 pshuflw xmm2,xmm2, 0xA0 ; copy v values pshufhw xmm2,xmm2, 0xA0 ; to get v0v0 yuv2rgbsse2 rgba32sse2output ; endloop add edi,32 add esi,8 add eax,4 add ebx,4 sub ecx, 1 ; apparently sub is better than dec jnz REPEATLOOP1 ENDLOOP1: ; Cleanup pop ebx pop eax pop ecx pop esi pop edi mov esp, ebp pop ebp ret SECTION .note.GNU-stack noalloc noexec nowrite progbits

  Read the article

• Wrappers of primitive types in arraylist vs arrays

  - by ismail marmoush

  Hi, In "Core java 1" I've read CAUTION: An ArrayList is far less efficient than an int[] array because each value is separately wrapped inside an object. You would only want to use this construct for small collections when programmer convenience is more important than efficiency. But in my software I've already used Arraylist instead of normal arrays due to some requirements, though "The software is supposed to have high performance and after I've read the quoted text I started to panic!" one thing I can change is changing double variables to Double so as to prevent auto boxing and I don't know if that is worth it or not, in next sample algorithm public void multiply(final double val) { final int rows = getSize1(); final int cols = getSize2(); for (int i = 0; i < rows; i++) { for (int j = 0; j < cols; j++) { this.get(i).set(j, this.get(i).get(j) * val); } } } My question is does changing double to Double makes a difference ? or that's a micro optimizing that won't affect anything ? keep in mind I might be using large matrices.2nd Should I consider redesigning the whole program again ?

  Read the article

• Counting entries in a list of dictionaries: for loop vs. list comprehension with map(itemgetter)

  - by Dennis Williamson

  In a Python program I'm writing I've compared using a for loop and increment variables versus list comprehension with map(itemgetter) and len() when counting entries in dictionaries which are in a list. It takes the same time using a each method. Am I doing something wrong or is there a better approach? Here is a greatly simplified and shortened data structure: list = [ {'key1': True, 'dontcare': False, 'ignoreme': False, 'key2': True, 'filenotfound': 'biscuits and gravy'}, {'key1': False, 'dontcare': False, 'ignoreme': False, 'key2': True, 'filenotfound': 'peaches and cream'}, {'key1': True, 'dontcare': False, 'ignoreme': False, 'key2': False, 'filenotfound': 'Abbott and Costello'}, {'key1': False, 'dontcare': False, 'ignoreme': True, 'key2': False, 'filenotfound': 'over and under'}, {'key1': True, 'dontcare': True, 'ignoreme': False, 'key2': True, 'filenotfound': 'Scotch and... well... neat, thanks'} ] Here is the for loop version: #!/usr/bin/env python # Python 2.6 # count the entries where key1 is True # keep a separate count for the subset that also have key2 True key1 = key2 = 0 for dictionary in list: if dictionary["key1"]: key1 += 1 if dictionary["key2"]: key2 += 1 print "Counts: key1: " + str(key1) + ", subset key2: " + str(key2) Output for the data above: Counts: key1: 3, subset key2: 2 Here is the other, perhaps more Pythonic, version: #!/usr/bin/env python # Python 2.6 # count the entries where key1 is True # keep a separate count for the subset that also have key2 True from operator import itemgetter KEY1 = 0 KEY2 = 1 getentries = itemgetter("key1", "key2") entries = map(getentries, list) key1 = len([x for x in entries if x[KEY1]]) key2 = len([x for x in entries if x[KEY1] and x[KEY2]]) print "Counts: key1: " + str(key1) + ", subset key2: " + str(key2) Output for the data above (same as before): Counts: key1: 3, subset key2: 2 I'm a tiny bit surprised these take the same amount of time. I wonder if there's something faster. I'm sure I'm overlooking something simple. One alternative I've considered is loading the data into a database and doing SQL queries, but the data doesn't need to persist and I'd have to profile the overhead of the data transfer, etc., and a database may not always be available. I have no control over the original form of the data. The code above is not going for style points.

  Read the article

• When NOT TO USE 'this' keyword?

  - by LifeH2O

  Sorry for asking it again, there are already 3 questions about this keyword. But all of them tell the purpose of 'this'. My question is when not to use 'this' keyword . OR Is it all right to use this keyword always in situation like the code class RssReader { private XmlTextReader _rssReader; private XmlDocument _rssDoc; private XmlNodeList _xn; protected XmlNodeList Item { get { return _xn; } } public int Count { get { return _count; } } public bool FetchFeed(String url) { this._rssReader = new XmlTextReader(url); this._rssDoc = new XmlDocument(); _rssDoc.Load(_rssReader); _xn = _rssDoc.SelectNodes("/rss/channel/item"); _count = _xn.Count; return true; } } here i have not used 'this' with "_xn" and "_count" also not with "_rssDoc.Load(_rssReader);" is it fine? Should i use "this" with all occurrences of class variables within the class?

  Read the article

• 'Fixed' for loop - what is more efficient?

  - by pimvdb

  I'm creating a tic-tac-toe game, and one of the functions has to iterate through each of the 9 fields (tic-tac-toe is played on a 3x3 grid). I was wondering what is more efficient (which one is perhaps faster, or what is the preferred way of scripting in such situation) - using two for nested loops like this: for(var i=0; i<3; i++) { for(var j=0; j<3; j++) { checkField(i, j); } } or hard-coding it like this: checkField(0, 0); checkField(0, 1); checkField(0, 2); checkField(1, 0); checkField(1, 1); checkField(1, 2); checkField(2, 0); checkField(2, 1); checkField(2, 2); As there are only 9 combinations, it would be perhaps overkill to use two nested for loops, but then again this is clearer to read. The for loop, however, will increment variables and check whether i and j are smaller than 3 every time as well. In this example, the time saving at least might be negligible, but what is the preferred way of coding in this case? Thanks.

  Read the article

• Why would this Lua optimization hack help?

  - by Ian Boyd

  i'm looking over a document that describes various techniques to improve performance of Lua script code, and i'm shocked that such tricks would be required. (Although i'm quoting Lua, i've seen similar hacks in Javascript). Why would this optimization be required: For instance, the code for i = 1, 1000000 do local x = math.sin(i) end runs 30% slower than this one: local sin = math.sin for i = 1, 1000000 do local x = sin(i) end They're re-declaring sin function locally. Why would this be helpful? It's the job of the compiler to do that anyway. Why is the programmer having to do the compiler's job? i've seen similar things in Javascript; and so obviously there must be a very good reason why the interpreting compiler isn't doing its job. What is it? i see it repeatedly in the Lua environment i'm fiddling in; people redeclaring variables as local: local strfind = strfind local strlen = strlen local gsub = gsub local pairs = pairs local ipairs = ipairs local type = type local tinsert = tinsert local tremove = tremove local unpack = unpack local max = max local min = min local floor = floor local ceil = ceil local loadstring = loadstring local tostring = tostring local setmetatable = setmetatable local getmetatable = getmetatable local format = format local sin = math.sin What is going on here that people have to do the work of the compiler? Is the compiler confused by how to find format? Why is this an issue that a programmer has to deal with? Why would this not have been taken care of in 1993? i also seem to have hit a logical paradox: Optimizatin should not be done without profiling Lua has no ability to be profiled Lua should not be optimized

  Read the article

• floating point equality in Python and in general

  - by eric.frederich

  I have a piece of code that behaves differently depending on whether I go through a dictionary to get conversion factors or whether I use them directly. The following piece of code will print 1.0 == 1.0 -> False But if you replace factors[units_from] with 10.0 and factors[units_to ] with 1.0 / 2.54 it will print 1.0 == 1.0 -> True #!/usr/bin/env python base = 'cm' factors = { 'cm' : 1.0, 'mm' : 10.0, 'm' : 0.01, 'km' : 1.0e-5, 'in' : 1.0 / 2.54, 'ft' : 1.0 / 2.54 / 12.0, 'yd' : 1.0 / 2.54 / 12.0 / 3.0, 'mile' : 1.0 / 2.54 / 12.0 / 5280, 'lightyear' : 1.0 / 2.54 / 12.0 / 5280 / 5.87849981e12, } # convert 25.4 mm to inches val = 25.4 units_from = 'mm' units_to = 'in' base_value = val / factors[units_from] ret = base_value * factors[units_to ] print ret, '==', 1.0, '->', ret == 1.0 Let me first say that I am pretty sure what is going on here. I have seen it before in C, just never in Python but since Python in implemented in C we're seeing it. I know that floating point numbers will change values going from a CPU register to cache and back. I know that comparing what should be two equal variables will return false if one of them was paged out while the other stayed resident in a register. Questions What is the best way to avoid problems like this?... In Python or in general. Am I doing something completely wrong? Side Note This is obviously part of a stripped down example but what I'm trying to do is come with with classes of length, volume, etc that can compare against other objects of the same class but with different units. Rhetorical Questions If this is a potentially dangerous problem since it makes programs behave in an undetermanistic matter, should compilers warn or error when they detect that you're checking equality of floats Should compilers support an option to replace all float equality checks with a 'close enough' function? Do compilers already do this and I just can't find the information.

  Read the article

• C++ converting back and forth from derived and base classes

  - by user127817

  I was wondering if there is a way in C++ to accomplish the following: I have a base class called ResultBase and two class that are Derived from it, Variable and Expression. I have a few methods that do work on vector<ResultBase> . I want to be able to pass in vectors of Variable and Expression into these methods. I can achieve this by creating a vector<ResultBase> and using static_cast to fill it with the members from my vector of Variable/Expression. However, once the vector has run through the methods, I want to be able to get it back as the vector of Result/Expression. I'll know for sure which one I want back. static_cast won't work here as there isn't a method to reconstruct a Variable/Expression from a ResultBase, and more importantly I wouldn't have the original properties of the Variables/Expressions The methods modify some of the properties of the ResultBase and I need those changes to be reflected in the original vectors. (i.e. ResultBase has a property called IsLive, and one of the methods will modify this property. I want this IsLive value to be reflected in the derived class used to create the ResultBase Whats the easiest way to accomplish this?

  Read the article

< Previous Page | 221 222 223 224 225 226 227 228 229 230 231 232  | Next Page >