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  • I'm trying to build a to-do-list application in Objective C but coming up short.

    - by lampShade
    I'm getting this error: -[NSCFArray insertObject:atIndex:]: attempt to insert nil Here is the .m file: /* IBOutlet NSTextField *textField; IBOutlet NSTabView *tableView; IBOutlet NSButton *button; NSMutableArray *myArray; */ #import "AppController.h" @implementation AppController -(IBAction)addNewItem:(id)sender { myArray = [[NSMutableArray alloc]init]; tableView = [[NSTableView alloc] init]; [tableView setDataSource:self]; [textField stringValue]; NSString *string = [[NSString alloc] init]; string = [textField stringValue]; [myArray addObject:string]; NSLog(@"%d",[myArray count]); NSLog(@"%@",string); } - (int)numberOfRowsInTableView:(NSTableView *)aTableView { return [myArray count]; } - (id)tableView:(NSTableView *)aTableView objectValueForTableColumn:(NSTableColumn *)aTableColumn row:(int)rowIndex { //NSString *data = [myArray objectAtIndex:rowIndex]; return [myArray objectAtIndex:rowIndex]; } @end

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  • Allocation algorithm help, using Python.

    - by Az
    Hi there, I've been working on this general allocation algorithm for students. The pseudocode for it (a Python implementation) is: for a student in a dictionary of students: for student's preference in a set of preferences (ordered from 1 to 10): let temp_project be the first preferred project check if temp_project is available if so, allocate it to them and make the project UNavailable to others Quite simply this will try to allocate projects by starting from their most preferred. The way it works, out of a set of say 100 projects, you list 10 you would want to do. So the 10th project wouldn't be the "least preferred overall" but rather the least preferred in their chosen set, which isn't so bad. Obviously if it can't allocate a project, a student just reverts to the base case which is an allocation of None, with a rank of 11. What I'm doing is calculating the allocation "quality" based on a weighted sum of the ranks. So the lower the numbers (i.e. more highly preferred projects), the better the allocation quality (i.e. more students have highly preferred projects). That's basically what I've currently got. Simple and it works. Now I'm working on this algorithm that tries to minimise the allocation weight locally (this pseudocode is a bit messy, sorry). The only reason this will probably work is because my "search space" as it is, isn't particularly large (just a very general, anecdotal observation, mind you). Since the project is only specific to my Department, we have their own limits imposed. So the number of students can't exceed 100 and the number of preferences won't exceed 10. for student in a dictionary/list/whatever of students: where i = 0 take the (i)st student, (i+1)nd student for their ranks: allocate the projects and set local_weighting to be sum(student_i.alloc_proj_rank, student_i+1.alloc_proj_rank) these are the cases: if local_weighting is 2 (i.e. both ranks are 1): then i += 1 and and continue above if local weighting is = N>2 (i.e. one or more ranks are greater than 1): let temp_local_weighting be N: pick student with lowest rank and then move him to his next rank and pick the other student and reallocate his project after this if temp_local_weighting is < N: then allocate those projects to the students move student with lowest rank to the next rank and reallocate other if temp_local_weighting < previous_temp_allocation: let these be the new allocated projects try moving for the lowest rank and reallocate other else: if this weighting => previous_weighting let these be the allocated projects i += 1 and move on for the rest of the students So, questions: This is sort of a modification of simulated annealing, but any sort of comments on this would be appreciated. How would I keep track of which student is (i) and which student is (i+1) If my overall list of students is 100, then the thing would mess up on (i+1) = 101 since there is none. How can I circumvent that? Any immediate flaws that can be spotted? Extra info: My students dictionary is designed as such: students[student_id] = Student(student_id, student_name, alloc_proj, alloc_proj_rank, preferences) where preferences is in the form of a dictionary such that preferences[rank] = {project_id}

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  • Can't find applicationSupportDirectory?

    - by Frost Li
    There is always a pre-written function at AppDelegate: (NSString *)applicationSupportDirectory { NSArray *paths = NSSearchPathForDirectoriesInDomains(NSApplicationSupportDirectory, NSUserDomainMask, YES); NSString *basePath = ([paths count] > 0) ? [paths objectAtIndex:0] : NSTemporaryDirectory(); return [basePath stringByAppendingPathComponent:@"SyncFile"]; } However, I can't call this method outside this class: id _appDelegate = (SyncFile_AppDelegate *)[[NSApplication sharedApplication] delegate]; NSLog(@"%@", [_appDelegate applicationSupportDirectory]); The compiler warned me that it can't find method applicationSupportDirectory... Does anyone know what's wrong with my code? Thank you very much!

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  • Python unit-testing with nose: Making sequential tests

    - by cool-RR
    I am just learning how to do unit-testing. I'm on Python / nose / Wing IDE. (The project that I'm writing tests for is a simulations framework, and among other things it lets you run simulations both synchronously and asynchronously, and the results of the simulation should be the same in both.) The thing is, I want some of my tests to use simulation results that were created in other tests. For example, synchronous_test calculates a certain simulation in synchronous mode, but then I want to calculate it in asynchronous mode, and check that the results came out the same. How do I structure this? Do I put them all in one test function, or make a separate asynchronous_test? Do I pass these objects from one test function to another? Also, keep in mind that all these tests will run through a test generator, so I can do the tests for each of the simulation packages included with my program.

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  • Create a Python User() class that both creates new users and modifies existing users

    - by ensnare
    I'm trying to figure out the best way to create a class that can modify and create new users all in one. This is what I'm thinking: class User(object): def __init__(self,user_id): if user_id == -1 self.new_user = True else: self.new_user = False #fetch all records from db about user_id self._populateUser() def commit(self): if self.new_user: #Do INSERTs else: #Do UPDATEs def delete(self): if self.new_user == False: return False #Delete user code here def _populate(self): #Query self.user_id from database and #set all instance variables, e.g. #self.name = row['name'] def getFullName(self): return self.name #Create a new user >>u = User() >>u.name = 'Jason Martinez' >>u.password = 'linebreak' >>u.commit() >>print u.getFullName() >>Jason Martinez #Update existing user >>u = User(43) >>u.name = 'New Name Here' >>u.commit() >>print u.getFullName() >>New Name Here Is this a logical and clean way to do this? Is there a better way? Thanks.

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  • random() in python

    - by Arkapravo
    In python the function random() generates a random float uniformly in the semi-open range [0.0, 1.0). In principle can it ever generate 0.0 (i.e. zero) and 1.0 (i.e. unity)? What is the scenario in practicality?

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  • How to 'assign' a value to an output reg in Verilog?

    - by Rafael Almeida
    ( insert really basic question disclaimer here ) More specifically, I have the following declaration: output reg icache_ram_rw And in some point of the code I need to put the zero value in this reg. Here's what I've tried and the outcomes: assign icache_ram_rw = 1'b0; ( declarative lvalue or port sink reg icache_ram_rw must be a wire ) icache_ram_rw <= 1'b0; ( instance gate/name for type "icache_ram_rw" expected - <= read ) How do I do it after all?!

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  • Dynamic type for List<T>?

    - by Brett
    Hi All, I've got a method that returns a List for a DataSet table public static List<string> GetListFromDataTable(DataSet dataSet, string tableName, string rowName) { int count = dataSet.Tables[tableName].Rows.Count; List<string> values = new List<string>(); // Loop through the table and row and add them into the array for (int i = 0; i < count; i++) { values.Add(dataSet.Tables[tableName].Rows[i][rowName].ToString()); } return values; } Is there a way I can dynamically set the datatype for the list and have this one method cater for all datatypes so I can specify upon calling this method that it should be a List<int or List<string> or List<AnythingILike>? Also, what would the return type be when declaring the method? Thanks in advance, Brett

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  • What is Adobe Flex? Is it just Flash II?

    - by Adam Davis
    Question Alright, I'm confused by all the buzzwords and press release bingo going on. What is the relationship between flash and flex: Replace flash (not really compatible) Enhance flash The next version of flash but still basically compatible Separate technology altogether ??? If I'm starting out in Flash now, should I just skip to Flex? Follow up Ok, so what I'm hearing is that there's three different parts to the puzzle: Flash The graphical editor used to make "Flash Movies", ie it's an IDE that focuses on the visual aspect of "Flash" (Officially Flash CS3?) The official name for the display plugins (ie, "Download Flash Now!") A general reference to the entire technology stack In terms of the editor, it's a linear timeline based editor, best used for animations with complex interactivity. Actionscript The "Flash" programming language Flex An Adobe Flash IDE that focuses on the coding/programming aspect of "Flash" (Flex Builder?) A Flash library that enhances Flash and makes it easier to program for (Flex SDK?) Is not bound to a timeline (as the Flash IDE is) and so "standard" applications are more easily accomplished. Is this correct?

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  • Python enumerate built-in error when using the start parameter

    - by TheJuice
    I'm modifying some code that calls enumerate on a list declared via a list comprehension e.g. self.groups = [Groups(self, idx) for idx in range(n_groups)] then later: for idx, group in enumerate(self.groups): # do some stuff but when I change the enumerate call to start at the 2nd list element via the start parameter e.g. for idx, group in enumerate(self.groups[1]): I get an exception: exceptions.TypeError: 'Group' object is not iterable Could someone explain why this is?

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  • Rails app w/ 2.2.0 embedd how to use ruby 1.8 vice 1.9

    - by Barb
    Hello all, I have just downloaded an app that is based on Rail 2.2.0 which is included in the app. I have just upgraded to Ruby 1.9 and I still have Ruby 1.8 on my machine. Is there a way I can tell this app to use Ruby 1.8 vice 1.9? Would it be easier to decouple the app from Rails 2.2.0 and upgrade it to Rails 2.3.6? If changing the rails would be easier, how do I do that?

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  • Ubiquity CmdUtils.setSelection won't replace HTML

    - by Josh Timmer
    I'm attempting to write a Ubiquity command that allows you to replace a selected link or URL pointing to an image with that image itself. However, the CmdUtils.setSelection() function (documented here) seems to do nothing if any html tags are present in the selection, making it useless for replacing any links. When selecting plain text, it functions exactly as intended, replacing the text with an <img src="text"/> tag. Is there something I'm missing, or will this function simply not allow me to replace html? If the latter is the case, is there a function or method that will allow me to do this? Any other advice is welcome as well! CmdUtils.CreateCommand({ name: "fetch-image", author: {name: "Josh Timmer"}, license: "GPL", description: "Replaces links or URLs pointing to images with the image itself", help: "Highlight text or a hyperlink and execute this command", takes: {"image URL": /.*/}, _getImgUrl: function(itemIq) { if (itemIq.html.indexOf("<a ",0) < 0) return itemIq.text; var refPos = itemIq.html.indexOf("href=\"",0); if (refPos < 0) return "Error, no URL found!"; var startPos = itemIq.html.indexOf("\"", refPos); var endPos = itemIq.html.indexOf("\"", startPos + 1); startPos += 1; var url = itemIq.html.substring(startPos, endPos); return url; }, preview: function(pblock, input) { pblock.innerHTML = "Image URL: " + this._getImgUrl(input) + "<br/><br/><img src='" + this._getImgUrl(input) + "'/>"; }, execute: function img_insert(input) { CmdUtils.setSelection("<img src='" + this._getImgUrl(input) + "'/>"); displayMessage("Executed: " + this._getImgUrl(input)); } });

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  • how to extract elements from a list in python ?

    - by Stefano Borini
    I feel suddenly uneasy of not being able to perform this operation easily. It could be that I'm tired, or that there's really no way (google didn't help), but... if you have a list in python, and want to extract element at indices say 1, 2 and 5 into a new list, how do you do ? This is how I did it, but I'm not very satisfied >>> a [10, 11, 12, 13, 14, 15] >>> [x[1] for x in enumerate(a) if x[0] in [1,2,5]] [11, 12, 15] any better way ? more in general, given a tuple with indices, how to use this tuple to extract the corresponding elements from a list, eventually with duplication (e.g. tuple (1,1,2,1,5) produces [11,11,12,11,15] )

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  • Cabal: Odd Error Message + Lack of Documentation

    - by voxcogitatio
    So I recently installed cabal (from the default binary of ArchLinux). I then tried to upgrade cabal as a user: cabal upgrade Cabal --user --prefix=$USER Resolving dependencies... cabal: fromFlag NoFlag. Use fromFlagOrDefault What I've already done: Googled the error message. Turned up the cabal source and little else. Looked at haskell-wiki on cabal-install. Looked through this guide. So basically I'm wondering: What's up with the error message? Could anyone point me in the direction of a cabal tutorial?

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  • In python, changing MySQL query based on function variables

    - by ensnare
    I'd like to be able to add a restriction to the query if user_id != None ... for example: "AND user_id = 5" but I am not sure how to add this into the below function? Thank you. def get(id, user_id=None): query = """SELECT * FROM USERS WHERE text LIKE %s AND id = %s """ values = (search_text, id) results = DB.get(query, values) This way I can call: get(5) get(5,103524234) (contains user_id restriction)

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  • How to determine which inheriting class is using an abstract class' methods.

    - by Kin
    In my console application have an abstract Factory class "Listener" which contains code for listening and accepting connections, and spawning client classes. This class is inherited by two more classes (WorldListener, and MasterListener) that contain more protocol specific overrides and functions. I also have a helper class (ConsoleWrapper) which encapsulates and extends System.Console, containing methods for writing to console info on what is happening to instances of the WorldListener and MasterListener. I need a way to determine in the abstract ListenerClass which Inheriting class is calling its methods. Any help with this problem would be greatly appreciated! I am stumped :X Simplified example of what I am trying to do. abstract class Listener { public void DoSomething() { if(inheriting class == WorldListener) ConsoleWrapper.WorldWrite("Did something!"); if(inheriting class == MasterListener) ConsoleWrapper.MasterWrite("Did something!"); } } public static ConsoleWrapper { public void WorldWrite(string input) { System.Console.WriteLine("[World] {0}", input); } } public class WorldListener : Listener { public void DoSomethingSpecific() { ConsoleWrapper.WorldWrite("I did something specific!"); } } public void Main() { new WorldListener(); new MasterListener(); } Expected output [World] Did something! [World] I did something specific! [Master] Did something! [World] I did something specific!

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  • Implement a 3D paint application: how to start?

    - by NewB
    Hello, I want to implement a paint-like application, which will enable kids to create and work with 3 dimensional objects. How can I start? What is the right approach? WPF, OpenGL, or Direct3D? (I prefer C# solutions, but C++ is OK also). Thank you all in advance! --NewB

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  • Creating a spider using Scrapy, Spider generation error.

    - by Nacari
    I just downloaded Scrapy (web crawler) on Windows 32 and have just created a new project folder using the "scrapy-ctl.py startproject dmoz" command in dos. I then proceeded to created the first spider using the command: scrapy-ctl.py genspider myspider myspdier-domain.com but it did not work and returns the error: Error running: scrapy-ctl.py genspider, Cannot find project settings module in python path: scrapy_settings. I know I have the path set right (to python26/scripts), but I am having difficulty figuring out what the problem is. I am new to both scrapy and python so there is a good possibility that I have failled to do something important. Also, I have been using eclipse with the Pydev plugin to edit the code if that might cause some problems.

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  • Why is my NSMutableArray returning nill?

    - by lampShade
    I have a very simple task: add the contents of a textField to an NSMutableArray.The Problem is the array is returning nill. I believe that it has something to do with the fact that the array I'm using is declared as an instance variable. /* IBOutlet NSTextField *textField; IBOutlet NSTabView *tableView; IBOutlet NSButton *button; NSMutableArray *myArray; */ #import "AppController.h" @implementation AppController -(IBAction)addNewItem:(id)sender { NSString *string = [textField stringValue]; NSLog(@"%@",string); [myArray addObject:string]; NSLog(@"%d",[myArray count]);//this outputs 0 why is that? }

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  • 3-d game programming

    - by Ygam
    what programming language/languages do they use to produce games lik Bioware's Dragon Age Origins and some other 3-d games like Call of Duty? If I would like to do 3d-game programming, where do I start? Are there even simple tutorials for this? I would like to do 3-d game programming for PC games:)

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