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  • Java - Console-like web applet.

    - by Dean
    Hey, I've been developing an application in the windows console with Java, and want to put it online in all of its console-graphics-glory. Is there a simple web applet API I can use to port my app over? I'm just using basic System.out and System.in functionality, but I'm happy to rebuild my I/O wrappers. I think something along these lines would be a great asset to any beginning Java developers who want to put their work online.

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  • Step by step help and guidance

    - by ChrisC
    Is there such a thing as a paid (or free would be GREAT, but unlikely I'm thinking) resource that could help a newbie with guidance and help as I create my first app (C# with SQLite db)? Stackoverflow is great, but a one-on-one person who was familiar with exactly what I'm doing would be even better.

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  • Loading attribute in XPATH, problem

    - by Nguyen Quoc Hung
    I've got a question about loading attribute in XPATH. I write short XML code to test: <?xml version="1.0" encoding="iso-8859-1"?> <?xml-stylesheet type="text/xsl" href="testDate.xsl"?> <element attribute="1/1/2100"> Hung </element> My XSL code: <?xml version="1.0" encoding="iso-8859-1"?> <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> <!--Handle the document: set up HTML page--> <xsl:template match="/"> <html> <head> </head> <body> This is a test <xsl:value-of select="element@attribute"/> </body> </html> </xsl:template> </xsl:stylesheet> Why it produces an error when loading the stylesheet? Would you please help me explain this? Thank you

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  • Small Python optional arguments question

    - by ooboo
    I have two functions: def f(a,b,c=g(b)): blabla def g(n): blabla c is an optional argument in function f. If the user does not specify its value, the program should compute g(b) and that would be the value of c. But the code does not compile - it says name 'b' is not defined. How to fix that? Someone suggested: def g(b): blabla def f(a,b,c=None): if c is None: c = g(b) blabla But this doesn't work, because maybe the user intended c to be None and then c will have another value.

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  • Haskell Ord instance with a Set

    - by mvid
    I have some code that I would like to use to append an edge to a Node data structure: import Data.Set (Set) import qualified Data.Set as Set data Node = Vertex String (Set Node) deriving Show addEdge :: Node -> Node -> Node addEdge (Vertex name neighbors) destination | Set.null neighbors = Vertex name (Set.singleton destination) | otherwise = Vertex name (Set.insert destination neighbors) However when I try to compile I get this error: No instance for (Ord Node) arising from a use of `Set.insert' As far as I can tell, Set.insert expects nothing but a value and a set to insert it into. What is this Ord?

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  • App logicstics & changes due to scope creep

    - by Kevin Brown
    I started an app that was initially a testing platform--user management, and managers that can view their employees tests. Recently, functionality has been extended (not built yet) to allow users to complete a test in place of an employee--basically adding a record, but no user. I have three tables in use for this: users(contains user info for login/security), profiles (all personal info: address, height, etc.), and survey (contains survey answers for user). How do I extend my application to encompass this functionality with minimal change to the structure? I assume that the best way to do this would be to insert records to the tables profiles and survey, and have no username/password/email? There MUST be a user_id associated b/c the tables are linked through the user_ids...

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  • iPhone: Error when using -(id)initWithNibName

    - by Nic Hubbard
    I am trying to use the following code, but I always get an error that I can find little information about: - (id)initWithNibName:@"MyRidesListView" bundle:nil { if ((self = [super initWithNibName:@"MyRidesListView" bundle:nil])) { // Custom initialization } return self; } Error: expected identifier before 'OBJC_STRING' token This seems like a simple method to be calling. This is for a UINavigationController. Ideas?

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  • is c++ STL algorithms and containers same across platforms and performance?

    - by Abhilash M
    After learning good amount of c++, i'm now into STL containers and algorithms template library, my major concerns are, 1) Is this library same across different platforms like MS, linux n other os? 2) will quality or efficiency of program c++ module decrease with more use of STL containers and algorithms, i think i can't customize it to all needs. 3) Is this template library good to use in linux system programming, kernel modules? 4) lastly can i use this in programming contests, because it relives a lot of coding and pressure off shoulders.

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  • A list vs. tuple situation in Python

    - by Alphonse
    Is there a situation where the use of a list leads to an error, and you must use a tuple instead? I know something about the properties of both tuples and lists, but not enough to find out the answer to this question. If the question would be the other way around, it would be that lists can be adjusted but tuples don't.

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  • Using an ampersand in scanf()

    - by Rob
    When I compile scanf("%s", &var);, gcc sends back a warning: warning: format ‘%s’ expects type ‘char *’, but argument 2 has type ‘char (*)[20]’ however when I compile scanf("%s", var);, no warning is applied. Both pieces of code work and the book I am reading specifically says to use the ampersand, but even it doesn't in some of the examples. My question is, should I continue to use the ampersand, even when the book doesn't specify?

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  • Any difference in compiler behavior for each of these snippets?

    - by HotHead
    Please consider following code: 1. uint16 a = 0x0001; if(a < 0x0002) { // do something } 2. uint16 a = 0x0001; if(a < uint16(0x0002)) { // do something } 3. uint16 a = 0x0001; if(a < static_cast<uint16>(0x0002)) { // do something } 4. uint16 a = 0x0001; uint16 b = 0x0002; if(a < b) { // do something } What compiler does in backgorund and what is the best (and correct) way to do above testing? p.s. sorry, but I couldn't find the better title :) EDIT: values 0x0001 and 0x0002 are only example. There coudl be any 2 byte value instead. Thank you in advance!

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  • Blogger Template: how to change the color of the border css

    - by Lirik
    Hi, I'm trying to change the borders in the style sheet of the template on my blog, but I've never done anything with css so I'm a little bit at a loss... I want to keep the dark background, but I want to create a small border with a slightly different color around my postings. If my guess is correct, then I should modify some of these definitions: body { background:$bgcolor; margin:0; color:$textcolor; font: x-small "Trebuchet MS", Trebuchet, Verdana, Sans-serif; font-size/* */:/**/small; font-size: /**/small; text-align: center; } a:link { color:$linkcolor; text-decoration:none; } a:visited { color:$visitedlinkcolor; text-decoration:none; } a:hover { color:$titlecolor; text-decoration:underline; } a img { border-width:0; } Here is a pastie with the entire template I'm using: http://pastie.org/932535 Is there a quick way to achieve the desired effect? Your help is appreciated!

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  • Form to sort an index in rails

    - by shmichael
    I'm a newcomer to Rails. I want to build a simple form that determines the sort order of a list. I've implemented a form in the likes of - <%= radio_button_tag :sort, "rating" %> <%= label_tag :sort_rating, "order by rating" %> <%= radio_button_tag :sort, "name" %> <%= label_tag :sort_name, "order by name" %> And now I am unsure how to implement the sort at the controller/model level. The aspects I am puzzled about are: Where should the sort be performed How could the sort parameter be persisted How could the code be reused Right now, I can't even get the selected sort method to remain selected after a submit. I would most appreciate any guidance or reference to an example.

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  • I need to speed up a function. Should I use cython, ctypes, or something else?

    - by Peter Stewart
    I'm having a lot of fun learning Python by writing a genetic programming type of application. I've had some great advice from Torsten Marek, Paul Hankin and Alex Martelli on this site. The program has 4 main functions: generate (randomly) an expression tree. evaluate the fitness of the tree crossbreed mutate As all of generate, crossbreed and mutate call 'evaluate the fitness'. it is the busiest function and is the primary bottleneck speedwise. As is the nature of genetic algorithms, it has to search an immense solution space so the faster the better. I want to speed up each of these functions. I'll start with the fitness evaluator. My question is what is the best way to do this. I've been looking into cython, ctypes and 'linking and embedding'. They are all new to me and quite beyond me at the moment but I look forward to learning one and eventually all of them. The 'fitness function' needs to compare the value of the expression tree to the value of the target expression. So it will consist of a postfix evaluator which will read the tree in a postfix order. I have all the code in python. I need advice on which I should learn and use now: cython, ctypes or linking and embedding. Thank you.

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  • Asp.net webservices

    - by Patel
    Hi everyone, I am new to asp.net .. i want to learn about web services.. can anyone pls provide me a good link or pdf on web services for reading it from basic.. thanks in advance..

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  • Help me decipher this output

    - by Bragaadeesh
    Hi, I have started learning Ruby recently and I was trying out the following piece of code. a=[1,2] b='slam dunk' a.each { |b| c=a*b; puts c;} I am getting the following output. I have no clue why. I expected an error or something to be thrown. Can someone explain me why this happens? 1 2 1 2 1 2 Thanks

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  • Why is my GUI unresponsive while a SwingWorker thread runs?

    - by Starchy
    Hello, I have a SwingWorker thread with an IOBound task which is totally locking up the interface while it runs. Swapping out the normal workload for a counter loop has the same result. The SwingWorker looks basically like this: public class BackupWorker extends SwingWorker<String, String> { private static String uname = null; private static String pass = null; private static String filename = null; static String status = null; BackupWorker (String uname, String pass, String filename) { this.uname = uname; this.pass = pass; this.filename = filename; } @Override protected String doInBackground() throws Exception { BackupObject bak = newBackupObject(uname,pass,filename); return "Done!"; } } The code that kicks it off lives in a class that extends JFrame: public void actionPerformed(ActionEvent event) { String cmd = event.getActionCommand(); if (BACKUP.equals(cmd)) { SwingUtilities.invokeLater(new Runnable() { public void run() { final StatusFrame statusFrame = new StatusFrame(); statusFrame.setVisible(true); SwingUtilities.invokeLater(new Runnable() { public void run () { statusFrame.beginBackup(uname,pass,filename); } }); } }); } } Here's the interesting part of StatusFrame: public void beginBackup(final String uname, final String pass, final String filename) { worker = new BackupWorker(uname, pass, filename); worker.execute(); try { System.out.println(worker.get()); } catch (InterruptedException e) { e.printStackTrace(); } catch (ExecutionException e) { e.printStackTrace(); } } } So far as I can see, everything "long-running" is handled by the worker, and everything that touches the GUI on the EDT. Have I tangled things up somewhere, or am I expecting too much of SwingWorker?

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  • Error in Python's os.walk?

    - by Mike Caron
    The os.walk documentation (http://docs.python.org/library/os.html? highlight=os.walk#os.walk), says I can skip traversing unwanted directories by removing them from the dir list. The explicit example from the docs: import os from os.path import join, getsize for root, dirs, files in os.walk('python/Lib/email'): print root, "consumes", print sum(getsize(join(root, name)) for name in files), print "bytes in", len(files), "non-directory files" if 'CVS' in dirs: dirs.remove('CVS') # don't visit CVS directories I see different behavior (using ActivePython 2.6.2). Namely for the code: >>> for root,dirs,files in os.walk(baseline): ... if root.endswith(baseline): ... for d in dirs: ... print "DIR: %s" % d ... if not d.startswith("keep_"): ... print "Removing %s\\%s" % (root,d) ... dirs.remove(d) ... ... print "ROOT: %s" % root ... I get the output: DIR: two Removing: two DIR: thr33 Removing: thr33 DIR: keep_me DIR: keep_me_too DIR: keep_all_of_us ROOT: \\mach\dirs ROOT: \\mach\dirs\ONE ROOT: \\mach\dirs\ONE\FurtherRubbish ROOT: \\mach\dirs\ONE\FurtherRubbish\blah ROOT: \\mach\dirs\ONE\FurtherRubbish\blah\Extracted ROOT: \\mach\dirs\ONE\FurtherRubbish\blah2\Extracted\Stuff_1 ... WTF? Why wasn't \\mach\dirs\ONE removed? It clearly doesn't start with "keep_".

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  • how to send an array of bytes over a TCP connection (java programming)

    - by Mark Roberts
    Can somebody demonstrate how to send an array of bytes over a TCP connection from a sender program to a receiver program in Java. (I'm new to Java programming, and can't seem to find an example of how to do this that shows both ends of the connection (sender and receiver.) If you know of an existing example, maybe you could post the link. (No need to reinvent the wheel.) P.S. This is NOT homework! :-)

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  • Using GA in GUI

    - by AlexT
    Sorry if this isn't clear as I'm writing this on a mobile device and I'm trying to make it quick. I've written a basic Genetic Algorithm with a binary encoding (genes) that builds a fitness value and evolves through several iterations using tournament selection, mutation and crossover. As a basic command-line example it seems to work. The problem I've got is with applying a genetic algorithm within a GUI as I am writing a maze-solving program that uses the GA to find a method through a maze. How do I turn my random binary encoded genes and fitness function (add all the binary values together) into a method to control a bot around a maze? I have built a basic GUI in Java consisting of a maze of labels (like a grid) with the available routes being in blue and the walls being in black. To reiterate my GA performs well and contains what any typical GA would (fitness method, get and set population, selection, crossover, etc) but now I need to plug it into a GUI to get my maze running. What needs to go where in order to get a bot that can move in different directions depending on what the GA says? Rough pseudocode would be great if possible As requested, an Individual is built using a separate class (Indiv), with all the main work being done in a Pop class. When a new individual is instantiated an array of ints represent the genes of said individual, with the genes being picked at random from a number between 0 and 1. The fitness function merely adds together the value of these genes and in the Pop class handles selection, mutation and crossover of two selected individuals. There's not much else to it, the command line program just shows evolution over n generations with the total fitness improving over each iteration. EDIT: It's starting to make a bit more sense now, although there are a few things that are bugging me... As Adamski has suggested I want to create an "Agent" with the options shown below. The problem I have is where the random bit string comes into play here. The agent knows where the walls are and has it laid out in a 4 bit string (i.e. 0111), but how does this affect the random 32 bit string? (i.e. 10001011011001001010011011010101) If I have the following maze (x is the start place, 2 is the goal, 1 is the wall): x 1 1 1 1 0 0 1 0 0 1 0 0 0 2 If I turn left I'm facing the wrong way and the agent will move completely off the maze if it moves forward. I assume that the first generation of the string will be completely random and it will evolve as the fitness grows but I don't get how the string will work within a maze. So, to get this straight... The fitness is the result of when the agent is able to move and is by a wall. The genes are a string of 32 bits, split into 16 sets of 2 bits to show the available actions and for the robot to move the two bits need to be passed with four bits from the agent showings its position near the walls. If the move is to go past a wall the move isn't made and it is deemed invalid and if the move is made and if a new wall is found then the fitness goes up. Is that right?

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