Search Results

Search found 1631 results on 66 pages for 'optimize'.

Page 40/66 | < Previous Page | 36 37 38 39 40 41 42 43 44 45 46 47  | Next Page >

• Change compilation flags in Qt under Mac OS X?

  - by Lior

  I installed Qt for Mac, and am compiling my Qt project after adding in the .Pro file CONFIG(release, debug|release):QMAKE_CXXFLAGS += -O3 -fomit-frame-pointer to optimize for speed. However, I always see that the command where g++ is ran, includes -Os, which optimizes for size. I would like to remove it. I tried several approaches, like CONFIG(release, debug|release):QMAKE_CFLAGS_RELEASE -= -Os CONFIG(release, debug|release):QMAKE_CXXFLAGS -= -Os and CONFIG(release, debug|release):QMAKE_CXXFLAGS = -O3 -fomit-frame-pointer CONFIG(release, debug|release):QMAKE_CFLAGS_RELEASE = -O3 -fomit-frame-pointer (no +) But nothing. -Os ALWAYS appear. How do I change this? I found the qmake.conf file under /usr/local/QT4.5/mkspecs. It includes a mac-g++.conf file, but I cannot change it, and chmod doesn't work: chmod: mac-g++.conf: Operation not permitted Any ideas?

  Read the article

• What happens before applicationDidFinishLaunching is invoked?

  - by nefsu

  I'm doing performance testing on my iphone app and I'm noticing that sometimes a good 3-4 secs elapse at startup before I start seeing my NSLogs from applicationDidFinishLaunching. I've optimized what happens once the code enters applicationDidFinishLaunching but I'm not sure how to optimize what goes on before that. I'm using a Default.png splash screen so it basically just stalls on that screen before it enters applicationDidFinishLaunching and starts doing something. Just to give you guys some context, I have no nib files and I'm using core animation, if that makes any difference. I have about 10 different controllers and my total bundle size is just under 2MBs.

  Read the article

• Cython Speed Boost vs. Usability

  - by zubin71

  I just came across Cython, while I was looking out for ways to optimize Python code. I read various posts on stackoverflow, the python wiki and read the article "General Rules for Optimization". Cython is something which grasps my interest the most; instead of writing C-code for yourself, you can choose to have other datatypes in your python code itself. Here is a silly test i tried, #!/usr/bin/python # test.pyx def test(value): for i in xrange(value): i**2 if(i==1000000): print i test(10000001) $ time python test.pyx real 0m16.774s user 0m16.745s sys 0m0.024s $ time cython test.pyx real 0m0.513s user 0m0.196s sys 0m0.052s Now, honestly, i`m dumbfounded. The code which I have used here is pure python code, and all I have changed is the interpreter. In this case, if cython is this good, then why do people still use the traditional Python interpretor? Are there any reliability issues for Cython?

  Read the article

• Compilier optimization of repeated accessor calls C#

  - by apocalypse9

  I've found recently that for some types of financial calculations that the following pattern is much easier to follow and test especially in situations where we may need to get numbers from various stages of the computation. public class nonsensical_calculator { ... double _rate; int _term; int _days; double monthlyRate { get { return _rate / 12; }} public double days { get { return (1 - i); }} double ar { get { return (1+ days) /(monthlyRate * days) double bleh { get { return Math.Pow(ar - days, _term) public double raar { get { return bleh * ar/2 * ar / days; }} .... } Obviously this often results in multiple calls to the same accessor within a given formula. I was curious as to whether or not the compiler is smart enough to optimize away these repeated calls with no intervening change in state, or whether this style is causing a decent performance hit. Further reading suggestions are always appreciated

  Read the article

• Subsonic SQLite Multiple Files

  - by Marcus Vinicius de LIma

  Hi, I have an application that must be accessed for many users. To optimize the performance I intend to store each user profile information at a independant database file. I need everytime a user login the application, to setup a new provider linked with his own database. All databases have the same structure. So while querying user the commom generated DAL classes must switch for the database file relative the the user. Is there a way for configure SubSonic for doing that switch at runtime? Thanks.

  Read the article

• Java Compiler: Optimization of "cascaded" ifs and best practices?

  - by jens

  Hello, does the Java Compiler optimize a statement like this if (a == true) { if (b == true) { if (c == true) { if(d == true) { //code to process stands here } } } } to if (a == true && b==true && c==true && d == true) So thats my first question: Do both take exactly the same "CPU Cycles" or is the first variant "slowlier". My Second questin is, is the first variant with the cascaded if considered bad programming style as it is so verbose? (I like the first variant as I can better logically group my expressions and better comment them (my if statements are more complex than in the example), but maybe thats bad proramming style?) and even slowlier, thats why I am asking... Thanks Jens

  Read the article

• groovy thread for urls

  - by Srinath

  I wrote logic for testing urls using threads. This works good for less number of urls and failing with more than 400 urls to check . class URL extends Thread{ def valid def url URL( url ) { this.url = url } void run() { try { def connection = url.toURL().openConnection() connection.setConnectTimeout(10000) if(connection.responseCode == 200 ){ valid = Boolean.TRUE }else{ valid = Boolean.FALSE } } catch ( Exception e ) { valid = Boolean.FALSE } } } def threads = []; urls.each { ur - def reader = new URL(ur) reader.start() threads.add(reader); } while (threads.size() 0) { for(int i =0; i < threads.size();i++) { def tr = threads.get(i); if (!tr.isAlive()) { if(tr.valid == true){ threads.remove(i); i--; }else{ threads.remove(i); i--; } } } Could any one please tell me how to optimize the logic and where i was going wrong . thanks in advance.

  Read the article

• Performance Improvement: Alternative for array_flip function.

  - by Rachel

  Is there any way I can avoid using array_flip to optimize performance. I am doing a select statement from database, preparing the query and executing it and storing data as an associative array in $resultCollection and than I have array op and for each element in $resultCollection am storing its outputId in op[] as evident from the code. I have explained code and so my question is how can I achieve an similar alternative for array_flip with using array_flip as I want to improve performance. $resultCollection = $statement->fetchAll(PDO::FETCH_ASSOC); $op = array(); //Looping through result collection and storing unicaOfferId into op array. foreach ($resultCollection as $output) { $op[] = $output['outputId']; } //Here op array has key as 0, 1, 2...and value as id {which I am interested in} //Flip op array to get unica offer ids as key $op = array_flip($op); //Doing a flip to get id as key. foreach ($ft as $Id => $Off) { $ft[$Id]['is_set'] = isset($op[$Id]); }

  Read the article

• Very simple jQuery rollover

  - by Gusepo

  I made a very simple jQuery img rollover function inspired by this one: http://www.smileycat.com/miaow/archives/000224.php. It just check all the imgs that contain _off in their name and swap them with an img with the same name but "_on" instead of "_off". Since I can't use background imgs in my layout, I feel that's an handy solution. But I've got the feeling that the swapping is not smooth, like if the function runs slow. What do you think? Are there ways to optimize it? Here is the code: function roll_over() { $("img[src*='_off']").hover( function() { var stringa = $(this).attr("src"); var stringa = stringa.replace("_off", "_on"); $(this).attr("src", stringa); }, function() { var stringa = $(this).attr("src"); var stringa = stringa.replace("_on", "_off"); $(this).attr("src", stringa); } ); }

  Read the article

• Background selector declaration in CSS

  - by Shivanand

  Hello, In CSS declaration for a selector is given as: background-attachment: scroll; background-color: transparent; background-image: url(/images/ucc/green/btn-part2.gif); background-repeat: no-repeat; background-position: right top; I want to optimize the code and change it to: background: scroll transparent url(/images/ucc/green/btn-part2.gif) no-repeat right top; My question is, Is this correct way and does it work in IE7/8, Firefox, Safari?

  Read the article

• mingw32-make : "Input line too long" issue

  - by hjsblogger

  We have a Makefile which runs on a Windows 2003 machine and we are using mingw32-make for it. Since the Makefile has many include paths, it exceeds the buffer size of 8K that the cmd can handle [Ref - http://support.microsoft.com/kb/830473/EN-US/due to which the compilation results in "input line too long" issue. I wanted to know the following - What would be the best way to optimize the Makefile as I have already removed unwanted compiler switches, include paths etc. Is there any way we can put all the INCLUDE paths in one .txt file and import it in the Makefile.I could not find any mingw32 documentation for the same. Any other inputs/hints/reference links are most welcome. Thanks, -HJSblogger

  Read the article

• T-SQL query to check number of existences

  - by abatishchev

  I have next approximate tables structure: accounts: ID INT, owner_id INT, currency_id TINYINT related to clients: ID INT and currency_types: ID TINYINT, name NVARCHAR(25) I need to write a stored procedure to check existence of accounts with specific currency and all others, i.e. client can have accounts in specific currency, some other currencies and both. I have already written this query: SELECT ISNULL(( SELECT 1 WHERE EXISTS ( SELECT 1 FROM [accounts] AS A, [currency_types] AS CT WHERE A.[owner_id] = @client -- sp param AND A.[currency_id] = CT.[ID] AND CT.[name] = N'Ruble' )), 0) AS [ruble], ISNULL(( SELECT 1 WHERE EXISTS ( SELECT A.[ID] FROM [accounts] AS A, [currency_types] AS CT WHERE A.[owner_id] = @client AND A.[currency_id] = CT.[ID] AND CT.[name] != N'Ruble' )), 0) AS [foreign] Is it possible to optimize it? I'm new to (T)SQL, so thanks in advance!

  Read the article

• Java Future and infinite computation

  - by Chris

  I'm trying to optimize an (infinite) computation algorithm. I have an infinte Sum to calculate ( Summ_{n- infinity} (....) ) My idea was to create several threads using the Future < construct, then combine the intermediate results together. My problem hoewer is that I need a certain precision. So I need to constantly calculate the current result while other threads keep calculating. My question is: Is there some sort of result queue where each finished thread can put its results in, while a main thread can receive those results and then either lets the computation continues or terminate the whole ExecutorService? Any Help would really be appreciated! Thanks!

  Read the article

• How fast can you make linear search?

  - by Mark Probst

  I'm looking to optimize this linear search: static int linear (const int *arr, int n, int key) { int i = 0; while (i < n) { if (arr [i] >= key) break; ++i; } return i; } The array is sorted and the function is supposed to return the index of the first element that is greater or equal to the key. They array is not large (below 200 elements) and will be prepared once for a large number of searches. Array elements after the n-th can if necessary be initialized to something appropriate, if that speeds up the search. No, binary search is not allowed, only linear search.

  Read the article

• Optimizing for speed - 4 dimensional array lookup in C

  - by Tiago

  I have a fitness function that is scoring the values on an int array based on data that lies on a 4D array. The profiler says this function is using 80% of CPU time (it needs to be called several million times). I can't seem to optimize it further (if it's even possible). Here is the function: unsigned int lookup_array[26][26][26][26]; /* lookup_array is a global variable */ unsigned int get_i_score(unsigned int *input) { register unsigned int i, score = 0; for(i = len - 3; i--; ) score += lookup_array[input[i]][input[i + 1]][input[i + 2]][input[i + 3]]; return(score) } I've tried to flatten the array to a single dimension but there was no improvement in performance. This is running on an IA32 CPU. Any CPU specific optimizations are also helpful. Thanks

  Read the article

• Update Rule in Temporal difference

  - by Betamoo

  The update rule TD(0) Q-Learning: Q(t-1) = (1-alpha) * Q(t-1) + (alpha) * (Reward(t-1) + gamma* Max( Q(t) ) ) Then take either the current best action (to optimize) or a random action (to explorer) Where MaxNextQ is the maximum Q that can be got in the next state... But in TD(1) I think update rule will be: Q(t-2) = (1-alpha) * Q(t-2) + (alpha) * (Reward(t-2) + gamma * Reward(t-1) + gamma * gamma * Max( Q(t) ) ) My question: The term gamma * Reward(t-1) means that I will always take my best action at t-1 .. which I think will prevent exploring.. Can someone give me a hint? Thanks

  Read the article

• mysql partitioning

  - by Yang

  just want to verify that database partition is implemented only at the database level, when we query a partitioned table, we still do our normal query, nothing special with our queries, the optimization is performed automatically when parsing the query, is that correct? e.g. we have a table called 'address' with a column called 'country_code' and 'city'. so if i want to get all the addresses in New York, US, normally i wound do something like this: select * from address where country_code = 'US' and city = 'New York' if now the table is partitioned by 'country_code', and i know that now the query will only be executed on the partition which contains country_code = US. My question is do I need to explicitly specify the partition to query in my sql statement? or i still use the previous statement and the db server will optimize it automatically? Thanks in advance!

  Read the article

• Do MyISAM holes get filled in automatically?

  - by NNN

  When you run a delete on a MyISAM table, it leaves a hole in the table until the table is optimized. This affects concurrent inserts. On the default setting, concurrent_inserts only work for tables without holes. However, in the documentation for MyISAM, under the concurrent_insert section it says: Enables concurrent inserts for all MyISAM tables, even those that have holes. For a table with a hole, new rows are inserted at the end of the table if it is in use by another thread. Otherwise, MySQL acquires a normal write lock and inserts the row into the hole. http://dev.mysql.com/doc/refman/5.0/en/server-system-variables.html#sysvar_concurrent_insert Does that mean MyISAM automatically fills in holes whenever a new row is insert into the table? Previously I thought the holes would not be fixed until you OPTIMIZE a table.

  Read the article

• Opposite of Bloom filter?

  - by abc

  Hi, I'm trying to optimize a piece of software which is basically running millions of tests. These tests are generated in such a way that there can be some repetitions. Of course, I don't want to spend time running tests which I already ran if I can avoid it efficiently. So, I'm thinking about using a Bloom filter to store the tests which have been already ran. However, the Bloom filter errs on the unsafe side for me. It gives false positives. That is, it may report that I've ran a test which I haven't. Although this could be acceptable in the scenario I'm working on, I was wondering if there's an equivalent to a Bloom filter, but erring on the opposite side, that is, only giving false negatives. I've skimmed through the literature without any luck.

  Read the article

• Intel Assembler optimization

  - by Søren Haagerup

  I'm currently trying to optimize the code emitted from a home-made compiler, for a home-made language. I've tried out Intel VTune to see where the bottlenecks are: http://www.imada.sdu.dk/~sorenh07/misc/vtune-assembly-optimization.png I find it very impressive that a "subl"-instruction is responsible for over 38% of the clockticks in a program running for 30-90 seconds! Can anybody give an explanation why? The "optimization report" feature in VTune apparently doesn't exist for programs not compiled with icc. Does there exist a program which suggests optimization for assembler code? (that is, not code coming from a high-level language).

  Read the article

• Write a sql to get the last data

  - by Lu Lu

  Hello everyone, I have a Realtime table with example data: Symbol Date Value ABC 1/3/2009 03:05:01 327 -- is last data for 'ABC' ABC 1/2/2009 03:05:01 326 ABC 1/2/2009 02:05:01 323 ABC 1/2/2009 01:05:01 313 BBC 1/3/2009 03:05:01 458 -- is last data for 'BBC' BBC 1/2/2009 03:05:01 454 BBC 1/2/2009 02:05:01 453 BBC 1/2/2009 01:05:01 423 Please help me to write a sql to return last data for all symbol. The result is: Symbol Date Value ABC 1/3/2009 03:05:01 327 BBC 1/3/2009 03:05:01 458 P/s: I use sql server 2005. And Realtime data is very big, please optimize the sql code. Thanks.

  Read the article

• Visual Studio: Add necessary using directives with macro

  - by Kiril

  Hello guys, I am trying to do the following. Imagine you are reading some LINQ article and you decide to copy/paste some code from the article to a newly created project. In most cases, if you directly compile you will probably get an error for missing a using directives or assembly reference. I am trying to optimize the process where I have to go each keyword, click on it with the mouse and hit Shift + Alt + F10 to add the using directive. I know that it is not that much pain, but for the sake of optimization, is it possible and at what cost? Best Regards, Kiril

  Read the article

• MySQL query optimization JOIN

  - by Pierre

  Hi, I need your help to optimize those mysql query, both are in my slow query logs. SELECT a.nom, c.id_apps, c.id_commentaire, c.id_utilisateur, c.note_commentaire, u.nom_utilisateur FROM comments AS c LEFT JOIN apps AS a ON c.id_apps = a.id_apps LEFT JOIN users AS u ON c.id_utilisateur = u.id_utilisateur ORDER BY c.date_commentaire DESC LIMIT 5; There is a MySQL INDEX on c.id_apps, a.id_apps, c.id_utilisateur, u.id_utilisateur and c.date_commentaire. SELECT a.id_apps, a.id_itunes, a.nom, a.prix, a.resume, c.nom_fr_cat, e.nom_edit FROM apps AS a LEFT JOIN cat AS c ON a.categorie = c.id_cat LEFT JOIN edit AS e ON a.editeur = e.id_edit ORDER BY a.id_apps DESC LIMIT 20; There is a MySQL INDEX on a.categorie, c.id_cat, a.editeur, e.id_edit and a.id_apps Thanks

  Read the article

• My code works in Debug mode, but not in Release mode.

  - by Nima

  Hi, I have a code in Visual Studio 2008 in C++ that works with files just by fopen and fclose. Everything works perfect in Debug mode. and I have tested with several datasets. But it doesn't work in release mode. It crashes all the time. I have turned off all the optimizations, also there is no dependency to anything(in the linker), and also I have set these: Optimization: Disabled(/Od) Keep Unreferenced Data. Do Not Remove Redundant Optimize for Windows98: NO I still keep wondering how it should not work under these circumstances. What else should I turn off to let it works as in debug mode? I think if it works in release mode but not in debug mode, it might be a coding fault but the other way looks weird. isn't it? I appreciate any help. --Nima

  Read the article

• How to solve such system with given parts of it? (maple)

  - by Kabumbus

  So I had a system #for given koefs k:=3; n:=3; #let us solve system: koefSolution:= solve({ sum(a[i], i = 0 .. k) = 0, sum(a[i], i = 0 .. k)-(sum(b[i], i = 0 .. k)) = 0, sum(i^n*a[i], i = 0 .. k)-(sum(i^(n-1)*b[i], i = 0 .. k)) = 0 }); So I have a vector like koefSolution := { a[0] = 7*a[2]+26*a[3]-b[1]-4*b[2]-9*b[3], a[1] = -8*a[2]-27*a[3]+b[1]+4*b[2]+9*b[3], a[2] = a[2], a[3] = a[3], b[0] = -b[1]-b[2]-b[3], b[1] = b[1], b[2] = b[2], b[3] = b[3]} I have a[0] so I try solve({koefSolution, a[0] = 1}); why it does not solve my system for given a[0]? ( main point here is to fill koefSolution with given a[] and b[] and optimize.)

  Read the article

< Previous Page | 36 37 38 39 40 41 42 43 44 45 46 47  | Next Page >