Search Results

Search found 7019 results on 281 pages for 'learning clojure'.

Page 193/281 | < Previous Page | 189 190 191 192 193 194 195 196 197 198 199 200  | Next Page >

• Graph Databases' Implementation

  - by user1478153

  I am having trouble visualizing a Graph Database. Visualizing an RDBMS is really very simple and I was able to understand from the first tutorial itself when I started learning it some 4-5 years ago. But I am not able to understand Graph Databases. I am also unable to get any good links on this topic, hence posting this question here. Specifically, I am looking for the following: Some really simple book/link on Graph Dbs Atleast some knowledge on the implementation details of a Graph DB (I hope all Graph DBs would be having atleast a few basic things in common). Thanks a lot in advance guys,

  Read the article

• Python Pari Library?

  - by silinter

  Pari/GP is an excellent library for functions relating to number theory. The problem is that there doesn't seem to be an up to date wrapper for python anywhere around, (pari-python uses an old version of pari) and I'm wondering if anyone knows of some other library/wrapper that is similar to pari or one that uses pari. I'm aware of SAGE, but it's far too large for my needs. GMPY is excellent as well, but there are some intrinsic pari functions that I miss, and I'd much rather use python than the provided GP environment. NZMATH, mpmath, scipy and sympy were all taken into consideration as well. On a related note, does anyone have any suggestions on loading the pari dll itself and using the functions contained in it? I've tried to very little success, other than loading it and learning about function pointers.

  Read the article

• How invoke live method with arguments

  - by dorelal

  I am learning how to write jQuery plugin. So why I am doing what I am doing does not matter. I writing a plugin called live2 which does nothing else but internally calls live method. (function($) { $.fn.live2 = function() { /* if there are no elements then just return */ if (!this.length) return this; return this.each(function() { var $this = $(this); jQuery.fn.live.apply(this, arguments); }); // end of return this.each(function()) }; // end of plugin })(jQuery); Above code should be invoked just live any live method. Instead of live use live2. $('#container').live2('click',function(){ return false; }) But the plugin is not working. Any idea what the fix should be.

  Read the article

• JNDI classes needed!!

  - by artaxerxe

  I have instaled in my computer a JDK version 1.6. (I'm learning about JNDI) When i run this: Hashtable env = new Hashtable(); env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.fscontext.RefFSContextFactory"); try { // Create the initial context Context ctx = new InitialContext(env); //... i get an error : Caused by: java.lang.ClassNotFoundException: com.sun.jndi.fscontext.RefFSContextFactory Caused by: java.lang.ClassNotFoundException: com.sun.jndi.fscontext.RefFSContextFactory Does it means that i need some classes to include in my classpath? I read in the tutorial that versions of jdk recently than v 3 doesn't need to download other classes. Thank advance!

  Read the article

• I wanted to be a programmer

  - by Henrik P. Hessel

  Hello, let me ask your opinion. I'm 25 now, living in Germany. I started with QBASIC, did some Java in Highschool, and after School I created some Websites in PHP. Now, because my Company is Microsoft Gold Partner, I've to use Microsoft all the time. C#, MSSQL, ASPX and Sharepoint <- I really hate it! So, in my spare I concentrate to gain more knowledge (C++, Java, Silverlight or WPF), because it feels that I'm so far behind, in comparison for example to you guys, or other older employees in my company. Do think that my behaviour is useful? Should I focus my time to become i.e. a pure C# Programmer? I did C# even before I started to learn some C++. Should I learn what do with pointers, memcpy and stuff like that, even if managed code brings us so much benefits? Or is it a waste of time, better invested in learning the latest technologies? rAyt

  Read the article

• Python Bitstream implementations

  - by Danielb

  I am writing a huffman implementation in Python as a learning exercise. I have got to the point of writing out my variable length huffman codes to a buffer (or file). Only to find there does not seem to be a bitstream class implemented by Python! I have had a look at the array and struct modules but they do not seem to do what I need without extra work. A bit of goggling turned up this bitstream implementation, which is more like what I am wanting. Is there really no comparable bitstream class in the Python standard library?

  Read the article

• Why can't I set the Image Source in WPF app?

  - by elmonty

  I'm just learning WPF. I'm using VS 2008. I've added an Image control to my XAML, and I added a GIF file to the project. If I use the XAML Designer's property panel to set the image's Source property, the drop-down list for the Source property contains the following: C:\Sample Project;component/pinHorizontal.gif There are several problems with this: My project, named "Sample Project," is not in the root of my drive. Why is ";component" in there? If I select this value as given, I get the error "Property value is not valid" (yeah, no kidding). If I go into the XAML source and set the Source property manually, like so: The XAML Designer gives me this error: "The file pinHorizontal.gif is not part of the project or its 'Build Action' property is not set to 'Resource'." Why is this task so difficult? How do I assign an image source?

  Read the article

• Swing code in sockets

  - by asb

  I am learning swings for making GUI. I was thinking which is the best possible way in case of socket with swings. 1. The whole swing code goes in the server file. All the handlers and logic in on server side. Client only create socket. 2. The server have logic part. The code for the swing to display interface goes on client side. Client Creates stream to send / rec. data from server. Whch is the good way out of 2 ?

  Read the article

• Naming convention for the primary key in a Table

  - by kwokwai

  Hi all, I am learning the Model relationship types in cakephp. I have built twotables and in one of the Table A, I got these fields in it: Table A {postID, topic, content} Table B {replyID, content, postID} And when I ran the web page, a bunch of error related to SQL popped up saying that cakephp couldn't find post_id. It is weird that I have already declared the $primaryKey to be using postID in the tableA.php under Models folder, but cakephp seemed want me to change the ID field to post_id instead of postID, because the error disappeared after I have changed the primaryKey to post_id. ANy ideas?

  Read the article

• Would a Socket Connection Outperform an Intarvaled Database Sweep and Requests?

  - by Jascha

  I'm building a small chat application to add to an existing framework. There will only be 20-50 users MAX at any one time. I was wondering if I could get away with updating a cache file containing (semi) live chat data for whichever users happen to be chatting just by performing timed queries and regular AJAX refreshes for new data as opposed to learning how to open and maintain a socket connection. I'm sure there are existing chat plug-ins out there. But I just had a hell of a time installing one and I could see building the whole damn thing taking just as much time as plugging one in. Am I off to a bad start? Thanks in advance -J (p.s. this is a semi closed network behind a php login so security isn't a great concern)

  Read the article

• Kohana 3 simple relations..

  - by matiit

  I'm trying to write a very simple cms (for learning purposes) in kohana 3 web framework. I have my db schemas and i want to map it to ORM but i have problems with relations. Schemas:articles and categories One article has one category. One category might has many articles of course. I think it is has_one relationship in article table.(?) Now php code. I need to create application/classes/models/article.php first, yes? class Model_Article extends ORM { protected // and i am not sure what i suppose to write here }

  Read the article

• Qt Graphics Scene mouse event propagation

  - by Olorin

  hello i'm learning qt and i'm doing the folowing to add some widgets to a graphics scene void MainWindow::addWidgets(QList<QWidget *> &list, int code) { if(code == CODE_INFO) { QWidget *layoutWidget = new QWidget(); QVBoxLayout *layout = new QVBoxLayout(); foreach(QWidget *w, list) { layout->addWidget(w); this->connect(((ProductInfo*)w), SIGNAL(productClicked()), this, SLOT(getProductDetails())); } layoutWidget->setLayout(layout); this->scene->addWidget(layoutWidget); } } my ProductInfo class processes mouse release and emits a signal void ProductInfo::mouseReleaseEvent(QMouseEvent *e) { QWidget::mouseReleaseEvent(e); emit productClicked(); } the problem is after adding the widgets to the scene they no longer get the mouse release event and don't emit productClicked signal but if i add them to the main window(not to the scene) they work as expected. What am i doing wrong?

  Read the article

• New to Rails. Doubt in Big URL Routing

  - by Gautam

  Hi, I have just started learning ruby on rails. I have a doubt wrt routing. Default Routing in Rails is :controller/:action/:id It works really fine for the example lets say example.com/publisher/author/book_name Could you tell me how do you work with something very big like this site http://www.telegraph.co.uk/sport/football/leagues/premierleague/chelsea/ Could you let me understand about the various controllers, actions, ids for the above mentioned url and how to code controller, models so as to achieve this. Could you suggest me some good tutorials when dealing with this big urls. Looking forward for your help Thanks in advance Gautam

  Read the article

• (iPhone SDK) How to link instance variables to a specific UILabel

  - by Timbo

  I'm using the iPhone SDK to build a simple application. I've created a brand new class which has a single variable. I need to make 5 instances of that class, which I have no trouble doing. I can create those instances and also set the variables without issue. What i do need to know is this: How do I link each of the 5 different instances of the variable to different and specific UILabels? Would I be better to create a method that dynamically creates and positions the labels? Thanks for your help in advance, I'm now to this iphone programming thing. I'm serious about learning fast though so I have posted a bounty on this question here : http://www.askearn.com/Responses.aspx?QuestionID=6542613f-7be8-4bb3-a950-aac218d47711

  Read the article

• Groovy 1.7 changes "final"?

  - by Aaron L. Carlow

  Just started learning Groovy, got the PragProg book "Programming Groovy" and had a problem compiling one of the sample scripts: class GCar2 { final miles = 0 def getMiles() { println "getMiles called" miles } def drive(dist) { if (dist > 0) { miles += dist } } } def car = new GCar2() println "Miles: $car.miles" println 'Driving' car.drive(10) println "Miles: $car.miles" try { print 'Can I see the miles? ' car.miles = 12 } catch (groovy.lang.ReadOnlyPropertyException ex) { println ex.message GroovyCar2.groovy: 20: cannnot access final field or property outside of constructor. @ line 20, column 35. def drive(dist) { if (dist > 0) miles += dist } ^ Groovy versions prior to 1.7 do not give an error. I looked through whatever documentation I could find and did not see the issue discussed. What is going on here? Aaron

  Read the article

• How to prevent Windows XP from stealing my input Ctrl-Space which is meant for Emacs

  - by Dean

  I am learning and using Emacs. What I found annoying is that Ctrl-Space input will be stolen by Windows XP to switch the language bar instead of setting the mark in Emacs. The "language bar" is the native input languages selection such as Chinese keyboard other than English keyboard. Is there a way to temporarily prevent XP from stealing it? I have disabled the language bar from "Regional and language options" from Control Panel but the problem still exists. It doesn't happen on my Windows 2000 desktop at office but it happens on my work Windows XP laptop. Thank you very much.

  Read the article

• Foreign keys in MySQL?

  - by icco

  I have been slowly learning SQL the last few weeks. I've picked up all of the relational algebra and the basics of how relational databases work. What I'm trying to do now is learn how it's implemented. A stumbling block I've come across in this, is foreign keys in MySQL. I can't seem to find much about the other than that they exist in the InnoDB storage schema that MySQL has. What is a simple example of foreign keys implemented in MySQL? Here's part of a schema I wrote that doesn't seem to be working if you would rather point out my flaw than show me a working example. CREATE TABLE `posts` ( `pID` bigint(20) NOT NULL auto_increment, `content` text NOT NULL, `time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP, `uID` bigint(20) NOT NULL, `wikiptr` bigint(20) default NULL, `cID` bigint(20) NOT NULL, PRIMARY KEY (`pID`), Foreign Key(`cID`) references categories, Foreign Key(`uID`) references users ) ENGINE=InnoDB;

  Read the article

• Writing a Compiler for .net - IL or Bytecode?

  - by Michael Stum

  I'm currently diving into the inner workings of .net, which means IL. As an exercise, I want to build a brainf..k compiler for .net (yes, they already exist, but as said it's for learning purposes). For the moment I'm just writing some text files that contain .il and compile them with ilasm, which works. But I wonder if I could/should go one level deeper and write bytecode directly? My "concern" is the Windows PE Stuff when compiling an EXE - instead of ilasm I would need some sort of Bytecode linker that would take my MSIL/CIL bytecode and generate the PE Stuff for it? Or do compilers "only" compile their language to IL and execute ilasm? Is there a managed version of it that I can call/embed from my compiler?

  Read the article

• How to Display Validation Error Messages on an ASP.NET MVC Page?

  - by Yardstermister

  I am pretty new to ASP.NET and C# I have spent the day learning the basics of the ASP.NET Membership provider I have built all my validator but are getting stuck at outputting my error message on the page. private void LogCreateUserError(MembershipCreateStatus status, string username) { string reasonText = status.ToString(); switch (status) { case MembershipCreateStatus.DuplicateEmail: case MembershipCreateStatus.DuplicateProviderUserKey: case MembershipCreateStatus.DuplicateUserName: reasonText = "The user details you entered are already registered."; break; case MembershipCreateStatus.InvalidAnswer: case MembershipCreateStatus.InvalidEmail: case MembershipCreateStatus.InvalidProviderUserKey: case MembershipCreateStatus.InvalidQuestion: case MembershipCreateStatus.InvalidUserName: case MembershipCreateStatus.InvalidPassword: reasonText = string.Format("The {0} provided was invalid.", status.ToString().Substring(7)); break; default: reasonText = "Due to an unknown problem, we were not able to register you at this time"; break; } //CODE TO WRITE reasonText TO THE HTML PAGE ?? } What is the best way to output the varible result onto the page as I have relied upon the built in ASP:Validators until now.

  Read the article

• concurrency in Java

  - by p1

  1]What is Non-blocking Concurrency and how is it different. 2] I have heard that this is available in Java. Are there any particular scenarios we should use this feature 3] Is there a difference/advantage of using one of these methods for a collection. What are the trade offs class List { private final ArrayList<String> list = new ArrayList<String>(); void add(String newValue) { synchronized (list) { list.add(newValue); } } } OR private final ArrayList<String> list = Collections.synchronizedMap(); The questions are more from a learning/understanding point of view. Thanks for attention.

  Read the article

• How do I specify the block object / predicate required by NSDictionary's keysOfEntriesPassingTest ?

  - by Todd

  For learning (not practical -- yet) purposes, I'd like to use the following method on an NSDictionary to give me back a set of keys that have values using a test I've defined. Unfortunately have no idea how to specify the predicate. NSDictionary keysOfEntriesPassingTest: - (NSSet *)keysOfEntriesPassingTest:(BOOL (^)(id key, id obj, BOOL *stop))predicate Let's say for example all my values are NSURLs, and I'd like to get back all the URLs that are on port 8080. Here's my stab at coding that -- though it doesn't really make sense to me that it'd be correct: NSSet * mySet = [myDict keysOfEntriesPassingTest:^(id key, id obj, BOOL *stop) { if( [[obj port] isEqual: [NSNumber numberWithInt: 8080]]) { return key; }] And that's because I get back the following compiler error: incompatible block pointer types initializing 'void (^)(struct objc_object *, struct objc_object *, BOOL *)', expected 'BOOL (^)(struct objc_object *, struct objc_object *, BOOL *)' What am I missing? I'd appreciate a pointer at some docs that go into more detail about the "Block object" that the predicate is supposed to be. Thanks!

  Read the article

• How do you use vim's quickfix feature?

  - by hora

  I'm a pretty new Vim user and I've found that its learning curve is quite steep (at least for me). I just installed this vim script for JavaScriptLint error checking, which shows errors in vim's quickfix window once I save a buffer. However, I don't know what to do next.. How do I 'scroll' through all the errors? How do I close the quickfix 'window'? How do I get it to check for errors after I've made changes to my code? I've looked at the vim quickfix docs but the amount of commands are overwhelming and I can't seem to find what I want. Any help would be appreciated. A side question: is there any way to have javascriptlint check for js errors for code residing in a .html file? Thanks!

  Read the article

• Restaurant review site in SharePoint

  - by Sisiutl

  I'm totally new to SharePoint but my company has adopted it for internal use. As a learning exercise I thought it would be fun to create a local restaurant review site. Can anyone point me to an example or tutorial to get me started? What I have in mind is a simple site where users can enter the restaurant name, cuisine style, address, a simple 5 point rating and price scale, and a short review. Other users could search for restaurants by cuisine and add their own reviews. We have SharePoint 2007 and MOSS. Thanks

  Read the article

• How to code Fizzbuzz in F#

  - by Russell

  I am currently learning F# and have tried (an extremely) simple example of FizzBuzz. This is my initial attempt: for x in 1..100 do if x % 3 = 0 && x % 5 = 0 then printfn "FizzBuzz" elif x % 3 = 0 then printfn "Fizz" elif x % 5 = 0 then printfn "Buzz" else printfn "%d" x What solutions could be more elegant/simple/better (explaining why) using F# to solve this problem? Note: The FizzBuzz problem is going through the numbers 1 to 100 and every multiple of 3 prints Fizz, every multiple of 5 prints Buzz, every multiple of both 3 AND 5 prints FizzBuzz. Otherwise, simple the number is displayed. Thanks :)

  Read the article

• Help with complex sql query

  - by eugeneK

  To make story short, i'm building self-learning banner management system. Users will be able to insert these banners to their site when banners will be shown based on sales/impressions ratio. I have 4 tables Banners bannerID int bannerImage varchar.... SmartBanners smartBannerID int smartBannerArrayID int bannerID int impressionsCount int visibility tinyint (percents) SmartBannerArrays smartBannerArrayID int userID int Statistics bannerID int saleAmountPerDay decimal... Each night i need to generate new "visibility" for each SmartBanner based on whole SmartBannerArray that same user has. So i need to get sum of impressions and sales for each bannerID in SmartBannerArray. All comes to my mind is to use double cursor, one will loop thought SmartBannerArrays get needed values for sum of impressions and sales and then inner loop which will access each SmartBanner and change it's "visibility" percentage based on (sales/impressions)/(sumOfSales/sumOfImpressions)*100 Hope you get the picture... Is there any other way to design better tables or not to use double cursor to avoid server overload ?

  Read the article

< Previous Page | 189 190 191 192 193 194 195 196 197 198 199 200  | Next Page >