Search Results

Search found 25585 results on 1024 pages for 'multiple variables'.

Page 508/1024 | < Previous Page | 504 505 506 507 508 509 510 511 512 513 514 515  | Next Page >

  • Does using functional languages help against computing values repeatedly?

    - by sharptooth
    Consider a function f(x,y): f(x,0) = x*x; f(0,y) = y*(y + 1); f(x,y) = f(x,y-1) + f(x-1,y); If one tries to implement that recursively in some language like C++ he will encounter a problem. Suppose the function is first called with x = x0 and y = y0. Then for any pair (x,y) where 0 <= x < x0 and 0 <= y < y0 the intermediate values will be computed multiple times - recursive calls will form a huge tree in which multiple leaves will in fact contain the same pairs (x,y). For pairs (x,y) where x and y are both close to 0 values will be computed numerous times. For instance, I tested a similar function implemented in C++ - for x=20 and y=20 its computation takes about 4 hours (yes, four Earth hours!). Obviously the implementation can be rewritten in such way that repeated computation doesn't occur - either iteratively or with a cache table. The question is: will functional languages perform any better and avoid repeated computations when implementing a function like above recursively?

    Read the article

  • Convert IIS / Tomcat Web Application to a multi-server environment.

    - by bill_the_loser
    I have an existing web application built in .Net, running on IIS that leverages a java servlet that we have running on Tomcat 5.5. We need to scale the application and I'm confused about what relates to our situation and what we need to do to get the servlet running on multiple servers. Right now I have 4 servers that can each individually process results, it almost seems like all I should have to do is add the ajp13 worker processes from three additional machines to the machine hosting the load balancer worker. But I can't imagine it should be that easy. What do I need to do to distribute the Tomcat load to the extra three machines? Thanks. Update: The current configuration is using a workers2.properties configuration file. From all of the documentation online I have not been able to determine the distinction between the workers.properties and the workers2.properties. Most of the examples that I have found are configuring the workers.properties and revolve around adding workers and registering them in the worker.list element. The workers2.properties does not appears to have a worker.list element and the syntax is different enough between the workers.properties and the workers2.properties that I'm doubtful that I can add that element. If I just add my multiple AJP workers to the workers2.properties file do I need to worry about the apparent lack of a worker.list element? [ajp13:localhost:8009] channel=channel.socket:localhost:8009 group=lb [ajp13:host2.mydomain.local:8009] channel=channel.socket:host2.mydomain.local:8009 group=lb [ajp13:host3.mydomain.local:8009] channel=channel.socket:host3.mydomain.local:8009 group=lb A couple of side notes... One I've noticed that sometime Tomcat doesn't seem to reload my changes and I don't know why. Also, I have no idea why this configuration has a workers2.properties and not a workers.properties. I've been assuming that it's based on version but I haven't seen anything to back up that assumption.

    Read the article

  • Good C++ array class for dealing with large arrays of data in a fast and memory efficient way?

    - by Shane MacLaughlin
    Following on from a previous question relating to heap usage restrictions, I'm looking for a good standard C++ class for dealing with big arrays of data in a way that is both memory efficient and speed efficient. I had been allocating the array using a single malloc/HealAlloc but after multiple trys using various calls, keep falling foul of heap fragmentation. So the conclusion I've come to, other than porting to 64 bit, is to use a mechanism that allows me to have a large array spanning multiple smaller memory fragments. I don't want an alloc per element as that is very memory inefficient, so the plan is to write a class that overrides the [] operator and select an appropriate element based on the index. Is there already a decent class out there to do this, or am I better off rolling my own? From my understanding, and some googling, a 32 bit Windows process should theoretically be able address up to 2GB. Now assuming I've 2GB installed, and various other processes and services are hogging about 400MB, how much usable memory do you think my program can reasonably expect to get from the heap? I'm currently using various flavours of Visual C++.

    Read the article

  • How to alter my mac os $PATH variable so that I can run the latest php version? [closed]

    - by skiabox
    Possible Duplicate: What are PATH and other environment variables, and how can I set or use them? I've just followed this article (http://mac.tutsplus.com/tutorials/server/upgrading-the-native-php-installation-on-os-x-mountain-lion/) to update my php installation using HomeBrew. The latest php version is indeed installed in /usr/local/bin The problem is that my $PATH variable is the following (doing an echo $PATH reveals it) : /usr/local/mysql/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/opt/X11/bin ...so the old version of php (that comes with mountain lion) always run first Any ideas on how to solve this? Thank you.

    Read the article

  • How can I speed up a MySQL restore from a dump file?

    - by Dave Forgac
    I am restoring a 30GB database from a mysqldump file to an empty database on a new server. When running the SQL from the dump file, the restore starts very quickly and then starts to get slower and slower. Individual inserts are now taking 15+ seconds. The tables are MyISAM. The server has no other active connections. SHOW PROCESSLIST; only shows the insert from the restore (and the show processlist itself). Does anyone have any ideas what could be causing the dramatic slowdown? Are there any MySQL variables that I can change to speed the restore while it is progressing?

    Read the article

  • Why doesn't Firefox redownload images already on a page?

    - by vvo
    Hello, i just read this article : https://developer.mozilla.org/en/HTTP_Caching_FAQ There's a firefox behavior (and some other browsers i guess) i'd like to understand : if i take any webpage and try to insert the same image multiple times in javascript, the image is only downloaded ONCE even if i specifiy all needed headers to say "do no ever use cache". (see article) I know there are workarounds (like addind query strings to end of urls etc) but why do firefox act like that, if i say that an image do not have to be cached, why is the image still taken from cache when i try to re-insert it ? Plus, what cache is used for this ? (I guess it's the memory cache) Is this behavior the same for dynamic inclusion for example ? ANSWSER IS NO :) I just tested it and the same headers for a js script will make firefox redownload it each time you append the script to the DOM. PS: I know you're wondering WHY i need to do that (appending same image multiple times and force to redownload but this is the way our app works) thank you The good answer is : firefox will store images for the current page load in the memory cache even if you specify he doesnt have to cache them. You can't change this behavior but this is odd because it's not the same for javascript files for example Could someone explain or link to a document describing how firefox cache WORKS?

    Read the article

  • How to initialize list with parent child relation

    - by user2917702
    Let's say I have the following classes. public class Parent { public string name; IList<Children> children; } public class Child { public string parentName; public int age; } As it is understandable, each parent can have multiple children, and we can have multiple parents. What is the best way to initialize these classes? Is it better to get all of the parents, and all of the children from database then use LINQ? IList<Parent> parents = GetParents()//assume this gets parents from db IList<Child> children = GetChildren() //assume this gets children from db foreach(Parent parent in parents) { parent.children = children.Where(x=>x.parentName==parent.name).ToList(); } or get all of the parents and iterate through each parent to query database by parentName to get children information? Due to requirement that I have, I cannot use datatable or dataset; I can only use datareader. IList<Parent> parents = GetParents()//assume this gets parents from db foreach(Parent parent in parents) { parent.children = GetChildrenByParentName();//assume this gets parents from db by parentName } Thank you

    Read the article

  • Considering moving from Java/Spring MVC to Grails

    - by MDS
    I'm currently using Java & Spring (MVC) to create a webapp, and I'm considering moving to Grails. I'd appreciate feedback/insight on the following: I have multiple application contexts in the current Java/Spring webapp that I load through the web.xml ContextLoaderListener; is it possible to have multiple application contexts in Grails? If, yes, how? This webapp extensively uses a CXF restful web service and the current Java/Spring webapp uses the bundled CXF HTTP client. Can I continue to use the (Java) CXF HTTP Client in Grails? I implemented Spring Security using a custom implementation of UserDetails and UserDetailsService, can I re-use these implementations in Grails "as is" or must I re-implement them? There is an instance where I've relied on Spring's jdbc template (rather than the available ORM) and an additional data source I defined in app context, can I re-use this in Grails? I plan on using Maven as the project management tool; are there any issues of using Maven with Grails where there is a combination of groovy and java?

    Read the article

  • Run BGInfo At Startup For All Users

    - by slickboy
    I have a Windows 7 image which I intend to deploy across a business. For simplicity I intend to install BGInfo on each machine and have it update each time a user logs in. From what I can see, when BGInfo creates a configuration file, the file contains variables which are local to each account - and therefore the configuration file will only work on the user account that created it. Has anyone any idea as to how make these configuration files 'generic' so that BGInfo will work for all accounts when they log in? At present I have the BGInfor application and a BGInfo configuration file saved on the C drive and I have written a batch file which is stored in the 'All Users/Start Menu/Startup' directory (which executes every time any user on the computer logs in), however this only works for the account which created the configuration file. Thanks for any help.

    Read the article

  • In Rails, how to respect :scope when using validates_uniqueness_of in an embedded object form?

    - by mkirk
    I have a Book model, which has_many Chapters (which belong_to a Book). I want to ensure uniqueness of Chapter titles, but only within the scope of a single book. The catch is that the form for creating chapters is embedded in the Book model's form (The Book model accepts_nested_attributes_for :chapters). Within the Chapter model: validates_uniqueness_of( :chapter_title, :scope = :book_id, :case_sensitive = false, :message = "No book can have multiple chapters with the same title.") However, when I submit the Book creation form (which also includes multiple embedded Chapter forms), if the chapter title exists in another chapter for a different book, I fail the validation test. Book.create( :chapters => [ Chapter.new(:title => "Introduction"), Chapter.new(:title => "How to build things") => Book 1 successfully created Book.create( :chapters => [ Chapter.new(:title => "Introduction"), Chapter.new(:title => "Destroy things") => Book 2 fails to validate second_book = Book.create( :chapters => [ Chapter.new(:title => "A temporary Introduction title"), Chapter.new(:title => "Destroy things") => Book 2 succesfully created second_book.chapters[0].title= "Introduction" => success second_book.chapters.save => success second_book.save => success Can anyone shed some light on how to do this? Or why it's happening?

    Read the article

  • Error "initializer element is not constant" when trying to initialize variable with const

    - by tomlogic
    I get an error on line 6 (initialize my_foo to foo_init) of the following program and I'm not sure I understand why. typedef struct foo_t { int a, b, c; } foo_t; const foo_t foo_init = { 1, 2, 3 }; foo_t my_foo = foo_init; int main() { return 0; } Keep in mind this is a simplified version of a larger, multi-file project I'm working on. The goal was to have a single constant in the object file, that multiple files could use to initialize a state structure. Since it's an embedded target with limited resources and the struct isn't that small, I don't want multiple copies of the source. I'd prefer not to use: #define foo_init { 1, 2, 3 } I'm also trying to write portable code, so I need a solution that's valid C89 or C99. Does this have to do with the ORGs in an object file? That initialized variables go into one ORG and are initialized by copying the contents of a second ORG? Maybe I'll just need to change my tactic, and have an initializing function do all of the copies at startup. Unless there are other ideas out there?

    Read the article

  • Help with simple javascript loop

    - by Gabriel
    Hello, I have a simple javascript that I'd like to loop for multiple elements. Here's my code: <script type='text/javascript'> for(i = 1; i < 100; i++) { $('#link'+i).click(function() { $('#container').removeClass(); $('#container').addClass('templateid'+i); }); } </script> What I'd like to achieve is the same addClass function for multiple id's (e.g. link2, link3, link4), with the corresponding class (e.g. template2, template3, template4). Any help would be hugely appreciated! For reference, an individual call like this one, does work, so I don't see why the loop above doesn't function the same: <script type='text/javascript'> $('#link2').click(function() { $('#container').removeClass(); $('#container').addClass('templateid2'); }); </script>

    Read the article

  • initialize jquery slider with hidden input value from database.

    - by ludwigs3rd
    I'm using a slider as user input for a screen. Basically it's a bulk update screen where there is a table with multiple rows, thus multiple sliders. I created it so that the hidden value is what gets posted in the form. <td> <input class="percentageProvidedHidden" type="hidden" name='<%= "Values[" + i + "].Percentage" %>' value='<%=item.Percentage %>' /> <div class="percentageProvidedSlider"></div> </td> I have the update working just fine (move slider changes hidden input value, submit, values are updated in db), however, I can't get the damn thing to initialize with the value of the hidden input (note the "value: " parameter below). In this case I think $(this) isn't actually $('percentageProvidedSlider') but the page itself. Can someone help me get the slider value to initialize with the hidden input field? I'm using ASP .Net MVC 2 so if there are any methods I should try with that I welcome them as well. $('.percentageProvidedSlider').slider( { min: 0, max: 100, step: 25, value: $(this).parents('tr').find('input.percentageProvidedHidden').val(), slide: function(e, ui) { var mypos = ui.value; $(this).find('.ui-slider-handle').text(ui.value); }, change: function(event, ui) { var myVal = $(this).slider("option", "value"); $(this).parents('tr').find('input.percentageProvidedHidden').val(myVal); var myDropDown = $(this).parents('tr').find('select.verified'); } });

    Read the article

  • Problems Expanding an Array in C++

    - by dxq
    I'm writing a simulation for class, and part of it involves the reproduction of organisms. My organisms are kept in an array, and I need to increase the size of the array when they reproduce. Because I have multiple classes for multiple organisms, I used a template: template <class orgType> void expandarray(orgType* oldarray, int& numitems, int reproductioncount) { orgType *newarray = new orgType[numitems+reproductioncount]; for (int i=0; i<numitems; i++) { newarray[i] = oldarray[i]; } numitems += reproductioncount; delete[] oldarray; oldarray = newarray; newarray = NULL; } However, this template seems to be somehow corrupting my data. I can run the program fine without reproduction (commenting out the calls to expandarray), but calling this function causes my program to crash. The program does not crash DURING the expandarray function, but crashes on access violation later on. I've written functions to expand an array hundreds of times, and I have no idea what I screwed up this time. Is there something blatantly wrong in my function? Does it look right to you? EDIT: Thanks for everyone's help. I can't believe I missed something so obvious. In response to using std::vector: we haven't discussed it in class yet, and as silly as it seems, I need to write code using the methods we've been taught.

    Read the article

  • What is and what is not replicated in a glassfish cluster with a mod_jk load balancer?

    - by Navigateur
    I have a Glassfish (3.1.2) cluster over 2 computers as nodes, with a mod_jk load balancer. Are servlet instance variables replicated perfectly? If not, how do I make sure it is? Are all actions, including method calls and disk writes, replicated perfectly? If not, how do I make sure they are? These may seem like stupid questions, but I'm not seeking "load balancing" as much as I am seeking exact replication to enable future upgrading without any service interruption. How do I achieve this if it is not already the case?

    Read the article

  • How to get values from SQL query made by php?

    - by Ole Jak
    So I made a query like this global $connection; $query = "SELECT * FROM streams "; $streams_set = mysql_query($query, $connection); confirm_query($streams_set); in my DB there are filds ID, UID, SID, TIME (all INT type exept time) So I am triing to print query relult into form <form> <select class="multiselect" multiple="multiple" name="SIDs"> <?php global $connection; $query = "SELECT * FROM streams "; $streams_set = mysql_query($query, $connection); confirm_query($streams_set); $streams_count = mysql_num_rows($streams_set); for ($count=1; $count <= $streams_count; $count++) { echo "<option value=\"{$count}\""; echo ">{$count}</option>"; } ?> </select> <br/> <input type="submit" value="Submit Form"/> </form> How to print out as "option" "values" SID's from my sql query?

    Read the article

  • Displaying Query Results Horizontally

    - by AndyD273
    I am wondering if it is possible to take the results of a query and return them as a CSV string instead of as a column of cells. Basically, we have a table called Customers, and we have a table called CustomerTypeLines, and each Customer can have multiple CustomerTypeLines. When I run a query against it, I run into problems when I want to check multiple types, for instance: Select * from Customers a Inner Join CustomerTypeLines b on a.CustomerID = b.CustomerID where b.CustomerTypeID = 14 and b.CustomerTypeID = 66 ...returns nothing because a customer can't have both on the same line, obviously. In order to make it work, I had to add a field to Customers called CustomerTypes that looks like ,14,66,67, so I can do a Where a.CustomerTypes like '%,14,%' and a.CustomerTypes like '%,66,%' which returns 85 rows. Of course this is a pain because I have to make my program rebuild this field for that Customer each time the CustomerTypeLines table is changed. It would be nice if I could do a sub query in my where that would do the work for me, so instead of returning the results like: 14 66 67 it would return them like ,14,66,67, Is this possible?

    Read the article

  • Can i get Source Path of Installed application?

    - by user123827
    is there any way to know that form which path an application was installed. for example I have firefox.exe in D:\Downloads\App\firefox.exe and when I install it, it is installed in C:\Program Files\Firefox but for some reason I need path from where Firefox was installed. that is "D:\Downloads\App\". like if this path is stored in some registry value? or in some other system variables? is there any way to get that path? I would like to get that path and then store it in some text file

    Read the article

  • How to approach socket programming between C# -> Java (Android)

    - by Alex
    I've recently knocked up a server/client app for Windows & Android that allows one to send a file from Windows to an android phone over a socket connection. It works great for a single file but trying to send multiple files over in a single stream is causing me problems. I've also realised that aside from the binary data, I will need to send messages over the socket to indicate error states and other application messages. I have little experience with network programming and and wondering what is the best way forward. Basically the C# server side of the app just goes into a listening state and uses Socket.SendFile to transmit the file. On Android I use the standard Java Socket.getInputStream() to receive the file. That works great for a single file transfer, but how should I handle multiple files and error/messaging information? Do I need to use a different socket for each file? Should I be using a higher level framework to handle this or can I send everything over the single socket? Any other suggestions for frameworks or learning materials?

    Read the article

  • jQuery bug when trying to insert partial elements before() / after() ?

    - by RedGlobe
    I'm trying to wrap a div around an element (my 'template' div) by using jQuery's before() and after(). When I try to insert a closing after the selected element, it actually gets placed before the target. Example: <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8" /> <title>Div Wrap</title> <script src="http://code.jquery.com/jquery-1.4.4.min.js"></script> <script> $('document').ready(function() { var beforestr = "<div id=\"wrap\"><div id=\"header\">Top</div><div id=\"page\">"; var afterstr = "</div><div id=\"footer\">Bottom</div></div>"; $('#template').before(beforestr); $('#template').after(afterstr); }); </script> </head> <body> <div id="template"> <h1>Page Title</h1> <p>Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Mauris placerat eleifend leo. Quisque sit amet est et sapien ullamcorper pharetra. <script>document.write('This script should still work and might contain variables. Please don\'t recommend concatenation.');</script> Donec non enim in turpis pulvinar facilisis.</p> </div> </body> </html> The result is: <div id="wrap"> <div id="header">Top</div> <div id="page"> </div> </div> <div id="template"> <h1>Page Title</h1> <p>Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Mauris placerat eleifend leo. Quisque sit amet est et sapien ullamcorper pharetra. This script should still work and might contain variables. Please don't recommend concatenation. Donec non enim in turpis pulvinar facilisis.</p> </div> <div id="footer">Bottom</div> Why are my closing wrap and page divs getting placed before the target, when I'm trying to place them after() ? Is there an alternative way to accomplish this (keeping in mind I may need to call script functions within the template div)? As I'm sure you're aware, best practices aren't what I'm going for here.

    Read the article

  • What db fits me?

    - by afvasd
    Dear Everyone I am currently using mysql. I am finding that my schema is getting incredibly complicated. I seek to find a new db that will suit my needs: Let's assume I am building a news aggregrator (which collects news from multiple website). I then run algorithms to determine if two news from different sites are actually referring to the same topic. I run this algorithm to cluster news together. The relationship is depicted below: cluster \--news1 \--word1 \--word2 \--news2 \--word3 \--news3 \--word1 \--word3 And then I will apply some magic and determine the importance of each word. Summing all the importance of each word gives me the importance of a news article. Summing the importance of each news article gives me the importance of a cluster. Note that above cluster there are also subgroups( like split by region etc), and categories (like sports, etc) which I have to determine the importance of that in a particular day per se. I have used views in the past to do so, but I realized that views are very slow. So i will normally do an insert into an actual table and index them for better performance. As you can see this leads to multiple tables derived like (cluster, importance), (news, importance), (words, importance) etc which can get pretty messy. Also the "importance" metric will change. It has become increasingly difficult to alter tables, update data (which I am using TRUNCATE TABLE) and then inserting from null. I am currently looking into something schemaless like Mongodb. I do not need distributedness. I would very much want something that is reasonably fast (which can be indexed) and something that is a lot more flexible that traditional RDMBS. Also, I need something that has some kind of ORM because I personally like ORM a lot. I am currently using sqlalchemy Please help!

    Read the article

  • Initializing ExportFactory using MEF

    - by Riz
    Scenario Application has multiple parts. Each part is in separate dll and implements interface IFoo All such dlls are present in same directory (plugins) The application can instantiate multiple instances of each part Below is the code snippet for the interfaces, part(export) and the import. The problem I am running into is, the "factories" object is initialized with empty list. However, if I try container.Resolve(typeof(IEnumerable< IFoo )) I do get object with the part. But that doesn't serve my purpose (point 4). Can anyone point what I am doing wrong here? public interface IFoo { string Name { get; } } public interface IFooMeta { string CompType { get; } } Implementation of IFoo in separate Dll [ExportMetadata("CompType", "Foo1")] [Export(typeof(IFoo), RequiredCreationPolicy = CreationPolicy.NonShared))] public class Foo1 : IFoo { public string Name { get { return this.GetType().ToString(); } } } Main application that loads all the parts and instantiate them as needed class PartsManager { [ImportMany] private IEnumerable<ExportFactory<IFoo, IFooMeta>> factories; public PartsManager() { IContainer container = ConstructContainer(); factories = (IEnumerable<ExportFactory<IFoo, IFooMeta>>) container.Resolve(typeof(IEnumerable<ExportFactory<IFoo, IFooMeta>>)); } private static IContainer ConstructContainer() { var catalog = new DirectoryCatalog(@"C:\plugins\"); var builder = new ContainerBuilder(); builder.RegisterComposablePartCatalog(catalog); return builder.Build(); } public IFoo GetPart(string compType) { var matchingFactory = factories.FirstOrDefault( x => x.Metadata.CompType == compType); if (factories == null) { return null; } else { IFoo foo = matchingFactory.CreateExport().Value; return foo; } } }

    Read the article

  • Roughly, what percentage of users will reach changed DNS?

    - by user3722246
    If my main server go offline for some reason for +1hrs, I'm planning to make a DNS change so users will access secondary server. It is not a perfect solution to decrease downtime but it is simple and would work. I'm not sure about its usefulness. So I have a question. If I'm going to make a DNS change to an A record for my domain (changing from one IP to another), what percentage of users are moved over to the new info in 2hrs? (roughly) I know this is a vague question and there are lots of variables but any input is welcomed because I had painful downtime experiences and don't want to experience it again. Thanks

    Read the article

  • What 20 Lines (or less) of code did you find really useful?

    - by Ygam
    You can share your code or other's code. Here's a snippet from an array function in Kohana: public static function rotate($source_array, $keep_keys = TRUE) { $new_array = array(); foreach ($source_array as $key => $value) { $value = ($keep_keys === TRUE) ? $value : array_values($value); foreach ($value as $k => $v) { $new_array[$k][$key] = $v; } } return $new_array; } It was helpful when I was uploading multiple images using multiple file upload forms. It turned this array array('images' => array( 'name' => array( 0 => 'img1', 1 => 'img0', 2 =>'img2' ), 'error' => array( 0 => '', 1 => '', 2 => '' into : array('images' => array( 0 => array( 'name' => 'img1' 'error' => '' ),//rest goes here How about you? What 20 or less lines of code did you find useful?

    Read the article

  • Page specific CSS or a single css file when developing a mobile (webkit) based site?

    - by Mike
    I am working on a mobile site for webkit browsers. I have been trying to find information on using multiple style sheets versus a single css file. There is a lot of information on this topic, but it not a lot of information pertaining to mobile browsers. My site will have a bunch of pages that while have page specific css. For a non-mobile site, it seems like generally people say that a single file will be faster, but that multiple files are easier to develop. However, on a mobile site is that still the case? If you put everything in one file, that will get cached after load, but that will make the first load slower. If you had page specific files, the first page would get loaded quicker, but every other page would then take a hit while making the page specific css http request. Does anyone have any thoughts on this? It sounds like they are saying one file is better as long as its under 1 MB (which my files def will)? http://www.yuiblog.com/blog/2010/07/12/mobile-browser-cache-limits-revisited/

    Read the article

< Previous Page | 504 505 506 507 508 509 510 511 512 513 514 515  | Next Page >