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• "Does not make sense to draw an image" - Warning after upgrade to MountainLion

  - by Tom

  After I upgraded my programming machine to MountainLion and XCode to the new version I get this warning printed into the console everytime I run my application: It does not make sense to draw an image when [NSGraphicsContext currentContext] is nil. This is a programming error. Break on void _NSWarnForDrawingImageWithNoCurrentContext() to debug. This will be logged only once. This may break in the future. I'm not using an Image anywhere in my Application and I searched the whole project for an image but couldn't find one. Does anybody know what could cause this? I'm using 2 nib files btw: One Popover and the Mainwindow. Neither of them contains an image. Edit: I found the line when this appears: [self.popover showRelativeToRect:[appDelegate.menulet frame] ofView:appDelegate.menulet preferredEdge:NSMinYEdge]; But none of those object is nil. Any suggestions? Edit 2: The Menulet is a NSView subclass btw. So I'm passing a view.

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• What are the reasons to use dos batch programs in Windows?

  - by DVK

  Question What would be a good (ideally, technical) reason to ever program some non-trivial task in dos batch language on a modern Windows system as opposed to downloading either PowerShell, or ActiveState Perl? To be more specific, I make the following two assumptions for the duration of this question: anyone technical enough to be able to write a medium-complexity batch script is technical enough to install either of the scripting interpreters. Neither of those two present enough of a learning curve for basic batch replacement tasks that said curve would outweigh the pain of doing any remotely-non-trivial task in batch. Notes "You need a batch program for autoexec.bat" is not a valid reason. Your autoexec.bat may consist of simply calling non-batch script. If you disagree with either of my 2 assumptions above, that's fine, and I may be wrong. But my question is specifically "assuming those 2 assumptions are correct, what would be the reason to still stick with batch?" If it makes it easier to suspend disbelief (in case you disagree with me), add in a 3rd assumption that the question is limited to people who already posess at least some modicum of PowerShell or Perl experience. To re-iterate - this is not meant to be a subjective question about how easy it is to learn PSh or ASPerl compared to doing advanced batch coding. That is a separate question that is too subjective to be bothered with in this post. Background: I used to do some fairly complicated batch programming back in the elder days, and remember batch as one of the worst possble programming languages I had encountered. The idea for this question came after seeing a bunch of batch questions on SO, and trying to grok the answer of one of them out of sheer curiosity and giving up in pain after a minute, exclaiming mentally "why would anyone go through this pain instead of doing that in 1 line of Perl?" :) My own plausible answer I assume there may be an an likely DOS-compatible system, which has DOS interpreter but has no compatible PowerShell or Perl... I'm not aware of one but not completely impossible.

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• What was Tim Sweeney thinking? (How does this C++ parser work?)

  - by Frank Krueger

  Tim Sweeney of Epic MegaGames is the lead developer for Unreal and a programming language geek. Many years ago posted the following screen shot to VoodooExtreme: As a C++ programmer and Sweeney fan, I was captivated by this. It shows generic C++ code that implements some kind of scripting language where that language itself seems to be generic in the sense that it can define its own grammar. Mr. Sweeney never explained himself. :-) It's rare to see this level of template programming, but you do see it from time to time when people want to push the compiler to generate great code or because they want to create generic code (for example, Modern C++ Design). Tim seems to be using it to create a grammar in Parser.cpp - you can see what look like prioritized binary operators. If that is the case, then why does Test.ae look like it's also defining a grammar? Obviously this is a puzzle that needs to be solved. Victory goes to the answer with a working version of this code, or the most plausible explanation, or to Tim Sweeney himself if he posts an answer. :-)

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• Debugging a working program on Mathematica 5 with Mathematica 7

  - by Neuschwanstein

  Hi everybody, I'm currently reading the Mathematica Guidebooks for Programming and I was trying to work out one of the very first program of the book. Basically, when I run the following program: Plot3D[{Re[Exp[1/(x + I y)]]}, {x, -0.02, 0.022}, {y, -0.04, 0.042}, PlotRange -> {-1, 8}, PlotPoints -> 120, Mesh -> False, ColorFunction -> Function[{x1, x2, x3}, Hue[Arg[Exp[1/(x1 + I x2)]]]]] either I get a 1/0 error and e^\infinity error or, if I lower the PlotPoints options to, say, 60, an overflow error. I have a working output though, but it's not what it's supposed to be. The hue seems to be diffusing off the left corner whereas it should be diffusing of the origin (as can be seen on the original output) Here is the original program which apparently runs on Mathematica 5 (Trott, Mathematica Guidebook for Programming): Off[Plot3D::gval]; Plot3D[{Re[Exp[1/(x + I y)]], Hue[Arg[Exp[1/(x + I y)]]]}, {x, -0.02, 0.022}, {y, -0.04, 0.042}, PlotRange -> {-1, 8}, PlotPoints -> 120, Mesh -> False] Off[Plot3D::gval]; However, ColorFunction used this way (first Plot3D argument) doesn't work and so I tried to simply adapt to its new way of using it. Well, thanks I guess!

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• UI design in flash games

  - by anon

  This question is more UI/Design-ish than hard-core programming is. Background: I've been coding in VIM/C++/OpenGL for a long time. I've come to realize that this (VIM/C++/OpenGL) isn't the way to learn about programming fancy/cool-looking/futuristic UIs; and that the design of such UIs belongs more so in the artistic/designer world of Flash. Anyway, I currently have a machine with MacOSX. What software should I install? What book should I read to learn about the artistic/design side of these futuristic UIs? [It's okay if the tools to design them are mouse clicking + graphical rather than coding based]. Question: what software packages + books to read to learn about creating fancy-looking / futuristic UIs in flash? Thanks! EDIT: PS these questions seem to get closed frequently. If you're going to vote to close for "duplicate question"; atleast provide a link to the question (with an answer).

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• What is the difference between AF_INET and PF_INET constants?

  - by Denilson Sá

  Looking at examples about socket programming, we can see that some people use AF_INET while others use PF_INET. In addition, sometimes both of them are used at the same example. The question is: Is there any difference between them? Which one should we use? If you can answer that, another question would be... Why there are these two similar (but equal) constants? What I've discovered, so far: The socket manpage In (Unix) socket programming, we have the socket() function that receives the following parameters: int socket(int domain, int type, int protocol); The manpage says: The domain argument specifies a communication domain; this selects the protocol family which will be used for communication. These families are defined in <sys/socket.h>. And the manpage cites AF_INET as well as some other AF_ constants for the domain parameter. Also, at the NOTES section of the same manpage, we can read: The manifest constants used under 4.x BSD for protocol families are PF_UNIX, PF_INET, etc., while AF_UNIX etc. are used for address families. However, already the BSD man page promises: "The protocol family generally is the same as the address family", and subsequent standards use AF_* everywhere. The C headers The sys/socket.h does not actually define those constants, but instead includes bits/socket.h. This file defines around 38 AF_ constants and 38 PF_ constants like this: #define PF_INET 2 /* IP protocol family. */ #define AF_INET PF_INET Python The Python socket module is very similar to the C API. However, there are many AF_ constants but only one PF_ constant (PF_PACKET). Thus, in Python we have no choice but use AF_INET. I think this decision to include only the AF_ constants follows one of the guiding principles: "There should be one-- and preferably only one --obvious way to do it." (The Zen of Python)

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• Source Control - XCode - Visual Studio 2005/2008 / 2010

  - by Mick Walker

  My apologies if this has been asked before, I wasnt quite sure if this question should be asked on a programming forum, as it more relates to programming environment than a particular technology, so please accept my (double) appologies if I am posting this in the wrong place, my logic in this case was if it effects the code I write, then this is the place for it. At home, I do a lot of my development on a Mac Pro, I do development for the Mac, iPhone and Windows on this machine (Xcode & Visual Studio - (multiple versions installed in bootcamp, but generally I run it via Parallels)). When visiting a client, I have a similar setup, but on my MacBook Pro. What I want is a source control solution to install on the Mac Pro, that will support both XCode and multiple versions of visual studio, so that when I visit a client, I can simply grab the latest copy from source control via the MacBook Pro. Whilst visiting the client, he / she may suggest changes, and minor ones I would tend to make on site, so I need the ability to merge any modified code back into the trunk of the project / solution when I return home. At the moment, I am using no source control at all, and rely on simply coping folders and overwriting them when I return from a client- thats my 'merge'!!! I was wondering if anyone had any ideas of a source provider I could use, which would support both Windows and Mac development environments, and is cheap (free would be better).

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• Disadvantage of OOP?

  - by Bragaadeesh

  Typically i dont want to know the specifics of the cons of OOPs, but it felt kind of weird when I had an argument at an interview I attended recently. The question that was posted to me was to tell me one disadvantage of OOP (Object Oriented Programming). At that time, I felt OOP to be the most matured level of programming after the procedural/functional models. So I replied to him that I dont see any negatives at all. But the interviewer said there are few and I asked him to list one if he does not mind. He gave an example that I cant digest well, he said that OOP pattern does not strictly implement inheritance rules and cited the satellite/rocket example where the body parts will disintegrate periodically to remove weight during rocket launch and said that inheritance does not support this. His example kind of felt very weird to me the reason being the application of inheritance to this example. Then I left the example aside and I had this doubt - Can we unplug class hierarchies in such a manner (I am kind of confident in Java its not possible) in an ideal Object Oriented Design?

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• How can I get the post text to be beside the avatar and not below it?

  - by William

  So I'm trying to create a forum with avatars, but right now the text is going below the avatars and not beside them. How can I fix this? Here is the CSS: .postbox{ text-align: left; margin: auto; background-color: #dbfef8; border: 1px solid #82FFCD; width: 100%; margin-top: 10px; } .postfooter{ width: 100%; border-top: 1px solid #82FFCD; } .postheader{ width: 100%; border-bottom: 1px solid #82FFCD; } .posttext{ width: 70%; text-align: left; border: 1px solid #82FFCD; } .postavi{ width: 20%; text-align: left; border: 1px solid #82FFCD; } and here is the html: <div class="postbox"><div class="postheader"> <b><span>CyanPrime!!~::##Admin##::~</span></b> </div> <div class="postavi"><img src="http://prime.programming-designs.com/test_forum/images/avatars/hacker.png" alt="hacker"/></div><div class="posttext">Let's test the Hacker Avatar.</div> <div class="postfooter"> [<a href="http://prime.programming-designs.com/test_forum/viewthread.php?thread=25">Reply</a>] 0 posts omitted. </div> </div>

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• Question - Setting dynamic HTML using Javascript to iFrames on Windows Mobile 6.1 - IE Mobile6

  - by swaroop

  Hi Experts, (excuse me if this is not the right forum to post - i couldn't find anything related to non-native programming and related to this topic) I Am trying to set a dynamic HTML into an iFrame on the webpage. I have tried a couple of things but none of them seem to work. I m able to read the innerHTML but can't seem to update it. // Able to read using document.getElementById('iFrameIdentifier').innerHTML; // On Desktop IE, this code works document.getElementById('iFrameId').contentWindow.document.open(); document.getElementById('iFrameId').contentWindow.document.write(dynamicHTML); document.getElementById('iFrameId').contentWindow.document.close(); Ideally the same function should work as how it works for div's but it says 'Object doesn't support this method or property". I have also tried document.getElementById('iFrameId').document.body.innerHTML. This apparently replaces the whole HTML of the page and not just the innerHTML. I have tried out a couple of things and they didn't work document.getElementById('iFrameId').body.innerHTML document.frames[0].document.body.innerHTML My purpose is to have a container element which can contain dynamic HTML that's set to it. I've been using it well till now when I observed that the setting innerHTML on a div is taking increasing amount of time because of the onClicks or other JS methods that are attached to the anchors and images in the dynamic HTML. Appears the JS methods or the HTML is some how not getting cleaned up properly (memory leak?) Also being discussed - http://www.experts-exchange.com/Programming/Languages/Scripting/JavaScript/Q_26185526.html#a32779090

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• How can I write classes that don't rely on "global" variables?

  - by Joel

  When I took my first programming course in university, we were taught that global variables were evil & should be avoided at all cost (since you can quickly develop confusing and unmaintainable code). The following year, we were taught object oriented programming, and how to create modular code using classes. I find that whenever I work with OOP, I use my classes' private variables as global variables, i.e., they can be (and are) read and modified by any function within the class. This isn't really sitting right with me, as it seems to introduce the same problems global variables had in languages like C. So I guess my question is, how do I stop writing classes with "global" variables? Would it make more sense to pretend I'm writing in a functional language? By this I mean having all functions take parameters & return values instead of directly modifying class variables. If I need to set any fields, I can just take the output of the function and assign it instead of having the function do it directly. This seems like it might make more maintainable code, at least for larger classes. What's common practice? Thanks!

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• Looking for Hardware that will easily interface with my .NET code.

  - by SkippyFire

  I'm a .NET C# developer looking to do some hardware interfacing/programming. I just want something super simple to mess around with. I have done one of those basic stamp projects, but I want something with less electrical work. A self-contained piece of hardware would be fine. I'm not really looking to do embedded programming... but that would actually be pretty cool if something was capable of running .net code. I'm looking for something that would be easy to connect, hopefully via USB. Serial ports seems to be more hit or miss nowadays with laptops and netbooks. Something I can easily send data to, like a mini LCD, or series of LED's. Better yet would be something that provides feedback, like a temperature sensor. The best would be something more featured that I could talk to. I would be able to send data to it, and it would send back responses. Maybe something like a servo that could report it's position? Or maybe something that I could set parameters on? Any ideas? Thanks in advance!

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• Codility-like sites for code golfs

  - by Adam Matan

  Hi, I've run into codility.com new cool service after listening to one of the recent stackoverflow.com podcasts. In short, it presents the user with a programming riddle to solve, within a given time frame. The user writes code in an online editor, and has the ability to run the program and view the standard output. After final submission, the user sees its final score and which tests failed him. Quoting Joel Spolsky: You are given a programming problem, you can do it in Java, C++, C#, C, Pascal, Python and PHP, which is pretty cool, and you have 30 minutes. And it gives you an editor in a webpage. And you've got to just start typing your code. And it's going to time you, basically you have to do it in a certain amount of time. And it actually runs your code and determines the performance characteristics of your code. It is intended for job interview screenings, but the idea seems very cool for code-golfs and for practicing new languages. Do you know if there's any proper open replacement? Adam

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• Job Opportunities

  - by James

  I have a few questions about my job opportunities and I appreaciate it if people could give me some feedback on what I should have in front of me. I am graduatating from a University of Wisconsin--La Crosse this December with a degree in CS and a math minor. I have a cumulative GPA of 3.84 and a major GPA of 4.0 right now (though I still have many classes in front of me). I already have a degree from the U of Minnesota (History, 3.69 GPA) and have worked in the business world for 3+ years (working for a small company in the baseball world, doing some computer programming, statistical research, operations work, technical writing, etc.) I know Java and C well, also am comfortable with Perl. I should have a good grasp of SQL by graduation. I am looking to get a nice programming job (and will be open to moving). Anyone have any advice on things I should learn etc? Also, I would like to know what everyone thinks about my chances of landing a decent job (I realize that is subjective). Also, any ideas on salary I should be looking for (say I am working a metropolitan area). Thanks.

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• Replacing/Extending Visual Studio's Generate Stub in Visual Studio 2010

  - by devoured elysium

  When we write the name of a method that doesn't exist, Visual Studio 2010 asks us if we'd like to generate a method stub with that name. What I'd like to know if is it possible to replace that same code stub generating command with one made by myself. I never did any kind of extensibility programming for Visual Studio so I have a couple of questions: How hard is it? Is it something I can learn in a couple of nights, or is it something that'll make me "lose" a lot of time? It seems to me that there isn't a lot of support for that kind of programming, as generally people are not that interested in developing solutions that extend the Visual Studio IDE. I searched on SO and it doesn't appear to have many threads about extending Visual Studio. I don't know how the generate method stub thing works in Visual Studio, but I just wanted to turn it into something a bit more flexible and useful. Has anyone dealt with these kind of things before, that can give me a pointer to where to start? I know of MS VSX site but that has a lot of resources and can be overwhelming for someone new to the subject as I am. What technology will I need to use? T4? Maybe I'll need to know a lot about the code, like Visual Studio does, so I can know other method's type arguments, names, etc. Is that what T4 is for? Thanks

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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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• Restricting dynamically loaded classes and jars based on a security policy

  - by Max

  Hi, I would like to dynamically load a set of jars or classes (i.e. plugins loaded at runtime). At the same time, I would like to restrict what these plugins are able to do in the JVM. For a test case, I would like to restrict them to pretty much everything (right now I'm just allowing one System.getProperty value to be read). I am currently using a security policy file, but I'm having difficulty specifying a policy for one folder or package in my codeBase, but not another. Here is how my policy looks now: grant codeBase "file:/home/max/programming/java/plugin/plugins/" { permission java.util.PropertyPermission "java.version", "read"; }; grant codeBase "file:/home/max/programming/java/plugin/api/" { permission java.security.AllPermission; }; Where (for testing purposes), all files in the plugins package and folder are restricted, but the classes in the api folder are not. Is this possible? Do I have to create a custom class loader? Is there a better way to go about doing this? Thanks.

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• C#, finding the largest prime factor of a number

  - by Juan

  Hello! I am new at programming and I am practicing my C# programming skills. My application is meant to find the largest prime factor of a number entered by the user. But my application is not returning the right answer and I dont really know where the problem is. Can you please help me? using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace ConsoleApplication1 { class Program { static void Main(string[] args) { Console.WriteLine("Calcular máximo factor primo de n. De 60 es 5."); Console.Write("Escriba un numero: "); long num = Convert.ToInt64(Console.ReadLine()); long mfp = maxfactor(num); Console.WriteLine("El maximo factor primo es: " + num); Console.Read(); } static private long maxfactor (long n) { long m=1 ; bool en= false; for (long k = n / 2; !en && k > 1; k--) { if (n % k == 0 && primo(k)) { m = k; en = true; } } return m; } static private bool primo(long x) { bool sp = true; for (long i = 2; i <= x / 2; i++) { if (x % i == 0) sp = false; } return sp; } } }

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• Organizing code, logical layout of segmented files

  - by David H

  I have known enough about programming to get me in trouble for about 10 years now. I have no formal education, though I've read many books on the subject for various languages. The language I am primarily focused on now would be php, atleast for the scale of things I am doing now. I have used some OOP classes for a while, but never took the dive into understanding principals behind the scenes. I am still not at the level I would like to be expression-wise...however my recent reading into a book titled The OOP Thought Process has me wanting to advance my programming skills. With motivation from the new concepts, I have started with a new project that I've coded some re-usable classes that deal with user auth, user profiles, database interfacing, and some other stuff I use regularly on most projects. Now having split my typical garbled spaghetti bowl mess of code into somewhat organized files, I've come into some problems when it comes to making sure files are all included when they need to be, and how to logically divide the scripts up into classes, aswell as how segmented I should be making each class. I guess I have rambled on enough about much of nothing, but what I am really asking for is advise from people, or suggested reading that focuses not on specific functions and formats of code, but the logical layout of projects that are larger than just a hobby project. I want to learn how to do things proper, and while I am still learning in some areas, this is something that I have no clue about other than just being creative, and trial/error. Mostly error. Thanks for any replies. This place is great.

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• Open Source CMS (.Net vs Java)

  - by CmsAndDotNetKindaGuy

  I must say up-front that this is not a strictly programming-related question and a very opinionated one. I am the lead developer of the dominant .Net CMS in my country and I don't like my own product :). Managerial decisions over what is important or not and large chunks of legacy code done before I joined gives me headache every day I go for work. Anyway, having a vast amount of experience in web industry and a very good grasp of C# and programming practices I'm designing my own CMS the past few months. Now the problem is that I'm an open source kinda guy so I have a dilemma. Should I use C# and .Net which has crippled multi-platform support or should I drop .Net entirely and start learning Java where I can create a truly open-source and cross-platform CMS? Please don't answer that I should contribute to an existing open source CMS. I ruled that out after spending a great deal of time searching for something similar in structure to what I have in mind. I am not a native speaker, so feel free to correct my syntax or rephrase my question.

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• Bash and regex problem : check for tokens entered into a Coke vending machine

  - by Michael Mao

  Hi all: Here is a "challenge question" I've got from Linux system programming lecture. Any of the following strings will give you a Coke if you kick: L = { aaaa, aab, aba, baa, bb, aaaa"a", aaaa"b", aab"a", … ab"b"a, ba"b"a, ab"bbbbbb"a, ... } The letters shown in wrapped double quotes indicate coins that would have fallen through (but those strings are still part of the language in this example). Exercise (a bit hard) show this is the language of a regular expression And this is what I've got so far : #!/usr/bin/bash echo "A bottle of Coke costs you 40 cents" echo -e "Please enter tokens (a = 10 cents, b = 20 cents) in a sequence like 'abba' :\c" read tokens #if [ $tokens = aaaa ]||[ $tokens = aab ]||[ $tokens = bb ] #then # echo "Good! now a coke is yours!" #else echo "Thanks for your money, byebye!" if [[ $token =~ 'aaaa|aab|bb' ]] then echo "Good! now a coke is yours!" else echo "Thanks for your money, byebye!" fi Sadly it doesn't work... always outputs "Thanks for your money, byebye!" I believe something is wrong with syntax... We didn't provided with any good reference book and the only instruction from the professor was to consult "anything you find useful online" and "research the problem yourself" :( I know how could I do it in any programming language such as Java, but get it done with bash script + regex seems not "a bit hard" but in fact "too hard" for anyone with little knowledge on something advanced as "lookahead"(is this the terminology ?) I don't know if there is a way to express the following concept in the language of regex: Valid entry would consist of exactly one of the three components : aaaa, aab and bb, regardless of order, followed by an arbitrary sequence of a or b's So this is what is should be like : (a{4}Ua{2}bUb{2})(aUb)* where the content in first braces is order irrelevant. Thanks a lot in advance for any hints and/or tips :)

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• What computer science topic am I trying to describe?

  - by ItzWarty

  I've been programming for around... 6-8 years, and I've begun to realize that I don't really know what really happens at the low-ish level when I do something like int i = j%348 The thing is, I know what j%348 does, it divides j by 348 and finds the remainder. What I don't know is HOW the computer does this. Similarly, I know that try { blah(); }catch(Exception e){ blah2(); } will invoke blah and if blah throws, it will invoke blah2... however, I have no idea how the computer does this instead of err... crashing or ending execution. And I figure that in order for me to get "better" at programming, I should probably know what my code is really doing. [This would probably also help me optimize and... err... not do stupid things] I figure that what I'm asking for is probably something huge taught in universities or something, but to be honest, if I could learn a little, I would be happy. The point of the question is: What topic/computer-science-course am I asking about? Because in all honesty, I don't know. Since I don't know what the topic is called, I'm unable to actually find a book or online resource to learn about the topic, so I'm sort of stuck. I'd be eternally thankful if someone helped me =/

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• how useful is Turing completeness? are neural nets turing complete?

  - by Albert

  While reading some papers about the Turing completeness of recurrent neural nets (for example: Turing computability with neural nets, Hava T. Siegelmann and Eduardo D. Sontag, 1991), I got the feeling that the proof which was given there was not really that practical. For example the referenced paper needs a neural network which neuron activity must be of infinity exactness (to reliable represent any rational number). Other proofs need a neural network of infinite size. Clearly, that is not really that practical. But I started to wonder now if it does make sense at all to ask for Turing completeness. By the strict definition, no computer system nowadays is Turing complete because none of them will be able to simulate the infinite tape. Interestingly, programming language specification leaves it most often open if they are turing complete or not. It all boils down to the question if they will always be able to allocate more memory and if the function call stack size is infinite. Most specification don't really specify this. Of course all available implementations are limited here, so all practical implementations of programming languages are not Turing complete. So, what you can say is that all computer systems are just equally powerful as finite state machines and not more. And that brings me to the question: How useful is the term Turing complete at all? And back to neural nets: For any practical implementation of a neural net (including our own brain), they will not be able to represent an infinite number of states, i.e. by the strict definition of Turing completeness, they are not Turing complete. So does the question if neural nets are Turing complete make sense at all? The question if they are as powerful as finite state machines was answered already much earlier (1954 by Minsky, the answer of course: yes) and also seems easier to answer. I.e., at least in theory, that was already the proof that they are as powerful as any computer.

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• iPhone: Proper use of View and View Controller

  - by Joel

  I've recently been doing a lot of Objective-C programming, and just got back into doing more iPhone development. I've done a lot of programming using MVC in other languages/frameworks, but I just want to make sure I'm using MVC properly in my iPhone Development. I created a new iPhone Utility Application, which creates two views: MainView and FlipsideView. Both have a controller (FlipsideViewController and MainViewController) and XIB file of their own. What I've been doing is putting the IBOutlet UIControl myControl variables in my MainView.h or FlipsideView.h files and then tying the controls in Interface Builder to those variables. Then I put any IBAction SomeAction myAction methods in the MainViewController.h and FlipsideViewController.h files and tying the events to those methods in Interface Builder. This seems to be conceptually correct, but seems to cause problems. Say I have a button that when clicked it changes a label's text. So the Controller doesn't have a clue of what the variable name of the label is in the OnTouchUp event handler for my button. So I make a @property for it. But since the MainViewController.view property isn't of type MyView, I get warnings or errors whenever I try to access those properties from the view controller. I am doing this correctly? Is there a better way to do this? If this is correct, how do I properly work with those variables without getting warnings or errors? Thanks

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• Bored with CS. What can I study that will make an impact?

  - by Eric Martinez

  So I'm going to an average university, majoring in CS. I haven't learned a damn thing and am in my third year. I've come to be really bored with studying CS. Initially, I was kind of misinformed and thought majoring in CS would make me a good "product creator". I make my money combining programming and business/marketing. But I have always done programming for the love of the art. I find things like algorithms interesting and want to be able to use CS to solve real world problems. I like the idea of bioinformatics and other hybrid studies. I'm not good enough, yet I hope, to really make a significant effort in those areas but I aspire to be. What are some other fields, open problems, and otherwise cool stuff to apply CS knowledge to in the real world? I'm really looking for something that will motivate me and re-excite me to continue studying CS. Edit: Like someone mentioned below. I am very interesting in the idea of being able to use computer science to help answer fundamental questions of life and the universe. But I'm not sure what is possible or how to begin.

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