Monthly Archives

Articles indexed in March 2010

Page 2142/2613 | < Previous Page | 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149  | Next Page >

• C# Monte Carlo Incremental Risk Calculation optimisation, random numbers, parallel execution

  - by m3ntat

  My current task is to optimise a Monte Carlo Simulation that calculates Capital Adequacy figures by region for a set of Obligors. It is running about 10 x too slow for where it will need to be in production and number or daily runs required. Additionally the granularity of the result figures will need to be improved down to desk possibly book level at some stage, the code I've been given is basically a prototype which is used by business units in a semi production capacity. The application is currently single threaded so I'll need to make it multi-threaded, may look at System.Threading.ThreadPool or the Microsoft Parallel Extensions library but I'm constrained to .NET 2 on the server at this bank so I may have to consider this guy's port, http://www.codeproject.com/KB/cs/aforge_parallel.aspx. I am trying my best to get them to upgrade to .NET 3.5 SP1 but it's a major exercise in an organisation of this size and might not be possible in my contract time frames. I've profiled the application using the trial of dotTrace (http://www.jetbrains.com/profiler). What other good profilers exist? Free ones? A lot of the execution time is spent generating uniform random numbers and then translating this to a normally distributed random number. They are using a C# Mersenne twister implementation. I am not sure where they got it or if it's the best way to go about this (or best implementation) to generate the uniform random numbers. Then this is translated to a normally distributed version for use in the calculation (I haven't delved into the translation code yet). Also what is the experience using the following? http://quantlib.org http://www.qlnet.org (C# port of quantlib) or http://www.boost.org Any alternatives you know of? I'm a C# developer so would prefer C#, but a wrapper to C++ shouldn't be a problem, should it? Maybe even faster leveraging the C++ implementations. I am thinking some of these libraries will have the fastest method to directly generate normally distributed random numbers, without the translation step. Also they may have some other functions that will be helpful in the subsequent calculations. Also the computer this is on is a quad core Opteron 275, 8 GB memory but Windows Server 2003 Enterprise 32 bit. Should I advise them to upgrade to a 64 bit OS? Any links to articles supporting this decision would really be appreciated. Anyway, any advice and help you may have is really appreciated.

  Read the article

• Learning material on SAT (Boolean Satisfiability Problem)

  - by Jules

  What are good documents to read on SAT (Boolean satisfiability problem) solvers. I have not been able to find good material via Google. The documents I found were either birds eye view, too advanced or corrupted PDF files... Which papers/documents do you recommend to learn about the algorithms in modern practical SAT solvers?

  Read the article

• .NET Application with SQL Server CE Database

  - by blu

  I just started using SQL Server CE 3.5 in my WinForms Application (C# in VS 2008 SP1). I've noticed a couple of interesting things I'd like some input on: 1. Copying of sdf file to bin My sdf file is located inside of an Infrastructure project that houses my repository implementations. When the application is first debugged the sdf was copied to debug\bin. This is where all future reads/writes operate. At some point when this is deployed the file will go into a data folder using Click Once, but during development where should I be putting this sdf? Is having it in the bin typical, or are there any other recommendations? 2. Updating sdf It appears that writing to the sdf file does not immediately update the database. I am using Linq-to-SQL and am calling SubmitChanges, but on read the values are not returned. However if I close the application and re-open it the added value is there. Is there an additional flush step I need to take? What is causing this, file locking, buffering, something else? Update 3. Unit Tests I have an MS test project, and the sdf file is not being copied to the correct output directory. I have the settings: Build Action: Content Copy to Output Directory: Copy Always The message is: System.Data.SqlServerCe.SqlCeException: The database file cannot be found. Check the path to the database. I appreciate any guidance on these questions, thanks. If there is a tutorial other than what is on MSDN that you know about that would be great too. Working with CE is proving to be a difficult task and I welcome any help I can find.

  Read the article

• printf anomaly after "fork()"

  - by pechenie

  OS: Linux, Language: pure C I'm moving forward in learning C progpramming in general, and C programming under UNIX in a special case :D So, I detected a strange (as for me) behaviour of the printf() function after using a fork() call. Let's take a look at simple test program: #include <stdio.h> #include <system.h> int main() { int pid; printf( "Hello, my pid is %d", getpid() ); pid = fork(); if( pid == 0 ) { printf( "\nI was forked! :D" ); sleep( 3 ); } else { waitpid( pid, NULL, 0 ); printf( "\n%d was forked!", pid ); } return 0; } In this case the output looks like: Hello, my pid is 1111 I was forked! :DHello, my pid is 1111 2222 was forked! Why the second "Hello" string occured in the child's output? Yes, it is exactly what the parent printed on it's start, with the parent's pid. But! If we place '\n' character in the end of each string we got the expected output: #include <stdio.h> #include <system.h> int main() { int pid; printf( "Hello, my pid is %d\n", getpid() ); // SIC!! pid = fork(); if( pid == 0 ) { printf( "I was forked! :D" ); //removed the '\n', no matter sleep( 3 ); } else { waitpid( pid, NULL, 0 ); printf( "\n%d was forked!", pid ); } return 0; } And the output looks like: Hello, my pid is 1111 I was forked! :D 2222 was forked! Why does it happen? Is it ... ummm ... correct behaviour? Or it's a kind of the 'bug'?

  Read the article

• Implementing Autocompletion in iPhone UITextField for contacts in address book

  - by nacho4d

  Hi, I would like to have a UITextField or UITextView in where as I do some input, alternatives will appear something similar to when you type an address in Mail Application, alternatives appear down and is possible tap them so get a better input user interface.(since there is no need to type the complete word or address or phone number) I do know how to fetch data from Address Book framework, also how to input text in UITextField/UITextView and its delegates but I don't know what kind of structure to use for fetching and showing data as the user do his/her input. I know basic CoreData if this matters, I hope I can get some help. UPDATE (2010/3/10): I don't have problem make a native-like GUI but I am asking about the algorithm, does any body knows what kind algorithm is best for this thing? maybe some binary tree? Or should I just fetch data from coredata everytime? Thanks Ignacio UPDATE (2010/03/28): I've been very busy these days, so I have not tried UISearchResults but it seems fine to me. BUT I wonder was there a necessity of deletion of the wining answer? I don't think is fair my reputation went down and couldn't see the winning answer. ;(

  Read the article

• Output Caching with IIS7 - How To for an dynamic aspx page?

  - by Lieven Cardoen

  I have a RetrieveBlob.aspx that gets some query string variables and returns an asset. Eeach url corresponds to a unique asset. In the RetrieveBlob.aspx a Cache Profile is set. In Web.Config the profile looks like (under system.web tag: <caching> <outputCache enableOutputCache="true" /> <outputCacheSettings> <outputCacheProfiles> <add duration="14800" enabled="true" varyByParam="*" name="AssetCacheProfile" /> </outputCacheProfiles> </outputCacheSettings> </caching> Ok, this works fine. When I put a breakpoint in the code behind of RetrieveBlob.aspx, it gets triggered the first time, and all the other times not. Now, I throw away the Cache Profile and instead I'm having this in my Web.Config under System.WebServer: <caching> <profiles> <add extension=".swf" policy="CacheForTimePeriod" kernelCachePolicy="CacheForTimePeriod" duration="00:08:00" /> <add extension=".flv" policy="CacheForTimePeriod" kernelCachePolicy="CacheForTimePeriod" duration="00:08:00" /> <add extension=".gif" policy="CacheForTimePeriod" kernelCachePolicy="CacheForTimePeriod" duration="00:08:00" /> <add extension=".png" policy="CacheForTimePeriod" kernelCachePolicy="CacheForTimePeriod" duration="00:08:00" /> <add extension=".mp3" policy="CacheForTimePeriod" kernelCachePolicy="CacheForTimePeriod" duration="00:08:00" /> <add extension=".jpeg" policy="CacheForTimePeriod" kernelCachePolicy="CacheForTimePeriod" duration="00:08:00" /> <add extension=".jpg" policy="CacheForTimePeriod" kernelCachePolicy="CacheForTimePeriod" duration="00:08:00" /> </profiles> </caching> Now the caching doesn't work anymore. What am I doing wrong? Is it possible to configure under Caching tag of System.WebServer a Caching Profile for a Dynamic aspx page? I already tried adding something like this: <add extension="RetrieveBlob.aspx" policy="CacheForTimePeriod" kernelCachePolicy="CacheForTimePeriod" duration="00:00:30" varyByQueryString="assetId, assetFileId" /> But it doesn't work. An example of an url is: http://{server}/{application}/trunk/RetrieveBlob.aspx?assetId=31809&assetFileId=11829

  Read the article

• Does a PHP per-function (or per-task) performance / benchmark reference exist?

  - by Lorren Biffin

  I'm running my own (albeit, basic) benchmarks in a linux-based sandbox. However, I'd love to find a per-function or per-task performance / benchmark reference or utility for comparison. Does this exist? Of course I've done my own fair diligence / searching and have so far come up empty handed.. (I'm primarily interested in information relevant to PHP 5.3) Thanks very much! :)

  Read the article

• Using Clojure with Vaadin

  - by Icarus

  Hi, Has anyone tried implementing a web application with Clojure ( using Compojure ) and Vaadin ? I had seen an article on using Clojure with JWT for creating web apps. Vaadin is based on GWT so you get a lot of the advantages of GWT ( though Vaadin is completely Server-centric). And Clojure gives the advantage that you can use any Java Based Framework, so what thoughts on the Clojure + Vaadin based web application ?

  Read the article

• Multiple variables in switch statement in c

  - by Muhammad Kashif Nadeem

  How to write following statement in c using switch statement in c int i = 10; int j = 20; if (i == 10 && j == 20) { Mymethod(); } else if (i == 100 && j == 200) { Yourmethod(); } else if (i == 1000 || j == 2000) // OR { Anymethod(); } Thanks

  Read the article

• gpg error - connection already closed?

  - by OopsForgotMyOtherUserName

  omg... hope someone can help me because I am so lost as to what to try next.... I don't know what is causing the error to happen, and I don't see how to figure it out... Keep going between the pgloader.conf examples and what I have, and I don't understand why I keep getting the 'connection already closed' error? The first few lines of my fr.conf is at the very end... I'd really appreciate / love some guidance here... Been trying to get this thing going all morning, and am even getting stuck just on this part... Running this command at the command line: /usr/bin/pgloader -c /var/mybin/pgconfs/fr.conf Yields this in the pgloader.log (with the process just hanging) more /tmp/pgloader.log 27-03-2010 12:22:53 pgloader INFO Logger initialized 27-03-2010 12:22:53 pgloader INFO Reformat path is ['/usr/share/python-support/pgloader/reformat'] 27-03-2010 12:22:53 pgloader INFO Will consider following sections: 27-03-2010 12:22:53 pgloader INFO fixed 27-03-2010 12:22:54 fixed INFO fixed processing 27-03-2010 12:22:54 pgloader INFO All threads are started, wait for them to terminate 27-03-2010 12:22:57 fixed ERROR connection already closed 27-03-2010 12:22:57 fixed INFO closing current database connection [pgsql] host = localhost port = 5432 base = frdb user = username pass = password [fixed] table = fr format = fixed filename = /var/www/fr.txt ...

  Read the article

• Where is the smallest PHP Forum?

  - by Xeoncross

  I know there are minimalist forums out there like punBB - but has anyone ever run into a super tiny forum/discussion system that was barely more than posting comments? Are there any microscopic forums hidden on google code or github? I found a PHP version of ruby's Beast written in CodeIgniter - but it was still pretty large.

  Read the article

• Trouble with mod_proxy and mongrel_rails

  - by x3ro

  Hey there I'm trying to set up a mod_proxy - mongrel combination, but somehow, apache/mod_proxy is unable to access mongrel locally. The following is my configuration for mod_proxy: ProxyRequests Off ProxyPreserveHost On <Location / ProxyPass http://localhost:3000/ ProxyPassReverse http://localhost:3000/ Order deny,allow Allow from all </Location Mongrel/Rails ist running just fine, because I can access it from my browser, and even with lynx on the server. However, I get the following error when trying to use the proxy: [error] [client 127.0.0.1] Invalid Content-Length I would appreciate any help :D PS: Oh, and the server is running Plesk to configure vhosts, if thats important.

  Read the article

• method which runs an exe file when the operating system starts up and remains hidden?

  - by Vibhor

  i had made a program using C++(devC++) using a for loop. when i run that an exe file is created. i pasted that exe file in startup folder. i want that file to run when computer starts or boot up and should remains hidden or in background and should not be visible on deskstop. pls reply...

  Read the article

• javascript: getting two sibling windows communicate

  - by romuwild

  i have 2 windows: window A and window B. -window A and window B have same domain -window A and window B doesn't have any parent window. first question: -is it possible for window A to get a reference of window B? second question: -what is the most elegant way to make window A notify something to window B? (modern browser supporting HTML5 restriction is not a problem) 2 ways i am aware of doing this: -messaging by server: where window B regulary asks the server if window A has notified something -messaging by local data (HTML5): when window A wants to notify something it changes the local data, window B regulary checks the local data for any change. but the 2 ways are not so elegant. for example it would be nice to get an reference of window B and using window.postMessage() (HTML5) ultimate goal is to make something like facebook where if you open 4 facebook tabs, and chat in one tab, the chat is actualized on every facebook tab, which is neat! thanks folks!

  Read the article

• How to make cakePHP retreive the data represented by a foreign key?

  - by XL

  Greetings cake experts, I have a question that I think would really help a lot of people getting started with cakePHP. I have a feeling it will be easy for some of you, but it is quite challenging to me. I have a simple database with multiple tables. I can't figure out how to make cakePHP display the values associated with a foreign key in an index view. Or create a view where the fields of my choice (the ones that make sense to users like location name - not location_id can be updated or viewed on a single page). I have created an example at http://lovecats.cakeapp.com that illustrate the question. If you look at the page and click the "list cats", you will notice that it shows the location_id field from the locations table. You will also notice that when you click "add cats", you must choose a location_id from the locations table. This is the automagic way that cakePHP builds the app. I want this to be the field location_name. The database is setup so that the table cats has a foreign key called location_id that has a relationship to a table called locations. This is my problem: I want these pages to display the location_name instead of the location_id. If you want to login to the application, you can go to http://cakeapp.com/sqldesigners/sql/lovecats and the password 'password' to look at the db relationships, etc. How do I have a page that shows the fields that I want? And is it possible to create a page that updates fields from all of the tables at once? This is the slice of cake that I have been trying to figure out and this would REALLY get me over a hump. You can download the app and sql from the above url.

  Read the article

• CDN for Images in ASP.NET

  - by Chris

  I am in the process of moving all of the images in my web application over to a CDN but I want to easily be able to switch the CDN on or off without having to hard code the path to the images. My first thought was to add an HttpHandler for image extensions that depending whether a variable in the web.config (something like ) will serve the image from the server or from the CDN. But after giving this a little though I think I've essentially ruled this out as it will cause ASP.NET to handle the request for every single image, thus adding overhead, and it might actually completely mitigate the benefits of using a CDN. An alternative approach is, since all of my pages inherit from a base page class, I could create a function in the base class that determines what path to serve the files from based off the web.config variable. I would then do something like this in the markup: <img src='<%= GetImagePath()/image.png' /> I think this is probably what I'll have to end up doing, but it seems a little clunky to me. I also envision problems with the old .NET error of not being able to modify the control collection because of the "<%=" though the "<%#" solution will probably work. Any thoughts or ideas on how to implement this?

  Read the article

• How to manage css of big websites within team environment without mess?

  - by jitendra

  Where multiple people can work on same css. is it possible to follow semantic name rules even in large websites. If I would write all main css first time with semantic names . then what and how i should guideline/instruction to other developer to maintain css readability, validation . and to know quickly where other are adding their own css if required. Right now every one just go to down and write required css classes ot IDs at bottom. and most of the time they don't write semantic names.

  Read the article

• Eclipse goto label not working in C

  - by Mr. Man

  Hi, I am using the Eclipse CDT and I have a goto label and a FILE definition after it and when I compile the project it gives me the error: Expression expected before FILE. Thanks in advance, Mr. Man

  Read the article

• (C++) using a method of an abstract class

  - by cemregoksu

  is it possible to use a method of an abstract class? how can i use a method of a class without having an instance?

  Read the article

• Assistance with PHP Regex

  - by BenTheDesigner

  Hi All I don't usually use regular expressions, hence my question. I need a regex to match the following: '{any-string}'. Any assistance appreciated. BenTheDesigner

  Read the article

• UIWebView: How do I control page display with a PDF?

  - by Dotnaught

  I have a PDF loaded in an iPhone app using UIWebView and it displays page numbers when the pages are scrolled manually. But I've had no luck figuring out how to access those numbers and set the page displayed. Any suggestions would be welcomed. Thanks.

  Read the article

• Android Compound Control internal click events

  - by Simon

  Hi, I'm writing a custom compound control that extends RelativeLayout. Inside this component, there is an ImageView. I add a OnClickListener to this ImageView to animate it when the user clicks on it. But when I am in an activity using this control and I add a OnClickListener on the control, this listener is never called. It only works when I remove the other listener I have on the ImageView. Does anybody knows how to "propagate" the event to the other listeners when I catch it inside the control? Thanks! PS: I would also like to know if there is an existing control that looks like the icons on the Android desktop. Like an icon with text underneath.

  Read the article

• Marker Recognition on Android (recognising Rubik's Cubes)

  - by greenie

  Hi everybody. I'm developing an augmented reality application for Android that uses the phone's camera to recognise the arrangement of the coloured squares on each face of a Rubik's Cube. One thing that I am unsure about is how exactly I would go about detecting and recognising the coloured squares on each face of the cube. If you look at a Rubik's Cube then you can see that each square is one of six possible colours with a thin black border. This lead me to think that it should be relativly simply to detect a square, possibly using an existing marker detection API. My question is really, has anybody here had any experience with image recognition and Android? Ideally I'd like to be able to implement and existing API, but it would be an interesting project to do from scratch if somebody could point me in the right direction to get started. Many thanks in advance.

  Read the article

• Avoid hardcoding iPhone screen size with programmatic view creation

  - by miorel

  Hi, I was looking up how to create a view programmatically and found the following example code: self.view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 480)]; This works great, except I don't like that it hardcodes the size of the screen. Is there a way to look up the size of the screen? An important point someone brought up is that if the app is running during a phone call then the screen will be slightly smaller because of the green "return to call" bar.

  Read the article

• C: what should I use for trace/diagnostic messages in a library?

  - by Cheeso

  In .NET I would use System.Diagnostics.Trace... What would I use in C or C++ ? right now I have a macro defined: diagnostics ON: #define DIAG(A) { printf(A); } debugging off: #define DIAG(A) { if(FALSE) {}} Is there a standard way?

  Read the article

< Previous Page | 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149  | Next Page >