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  • Should I be looking for developers with specific skill sets or generalists that need to learn?

    - by Lostsoul
    Thanks to the great help of this site and SO, I've been able to make a prototype of a software I want to sell but unfortunately although the prototype works I think my code quality is very low. I didn't use much OOP or design patterns so although my code is understandable to me, I think a normal developer would faint if they had to read it. So I wanted to hire a developer to make it a bit more better quality and improve some of my implementations of API's that I may have not done correctly. I'm having problems hiring a developer though. I have met 2 developers and had them read my software specs.The problem is, they lacked my business's domain knowledge(which is completely understandable and no biggie) but they also lacked knowledge of the underlying tech systems I used such as Hadoop, Hbase, Cuda, etc..I spent alot of time explaining map/reduce, bigtables and other technologies I used. I thought it was common knowledge because of my interactions with people on this site but the people I met with mentioned they never had to deal with these things so they didn't know it. My question is, for software projects that are hiring contractor developers is it a danger if the developer does not have experience with the underlying technologies? or can a general developer who is accomplished in another area realistically pick up new technologies? I did a very very quick back of envelope calculation and I think the upfront costs would be similar if I hire a student or developer with no experience in my technologies who will work many hours versus hiring a highly experienced developer who charges double but finishes in half the time but what other risks should I be considering or worried about? Also, should if I do hire a generalist, should I be paying for the time it takes them to learn hadoop or cuda if they are contractors(seems to make business sense but not sure how fair it is to them if they do not use the skill again). I'm a bit confused so any suggestions would be great.

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  • android shut-down errors / thread problems

    - by iQue
    Im starting to deal with some stuff in my game that I thought were "minor problems" and one of these are that I get an error every time I shut down my game that looks like this: 09-05 21:40:58.320: E/AndroidRuntime(30401): FATAL EXCEPTION: Thread-4898 09-05 21:40:58.320: E/AndroidRuntime(30401): java.lang.NullPointerException 09-05 21:40:58.320: E/AndroidRuntime(30401): at nielsen.happy.shooter.MainGamePanel.render(MainGamePanel.java:94) 09-05 21:40:58.320: E/AndroidRuntime(30401): at nielsen.happy.shooter.MainThread.run(MainThread.java:101) on these lines is my GameViews rendering-method and the line in my Thread that calls my GameViews rendering-method. Im guessing Something in my surfaceDestroyed(SurfaceHolder holder) is wrong, or maybe Im not ending the tread in the right place. My surfaceDestroyed-method: public void surfaceDestroyed(SurfaceHolder holder) { Log.d(TAG, "Surface is being destroyed"); boolean retry = true; ((MainThread)thread).setRunning(false); while (retry) { try { ((MainThread)thread).join(); retry = false; } catch (InterruptedException e) { } } Log.d(TAG, "Thread was shut down cleanly"); } Also, In my activity for this View my onPaus, onDestoy and onStop are empty, do I maybe need to add something there? The crash occurs when I press my home-button on the phone, or any other button that makes the game stop. But as I understand it the onPaus is called when you press the Home-button.. This is really new territory for me so Im sorry if im missing something obvious or something really big. adding my surfaceCreated method asweel since that is where I start this thread: public void surfaceCreated(SurfaceHolder holder) { controls = new GameControls(this); setOnTouchListener(controls); timer1.schedule(new Task(this), 0, delay1); thread.setRunning(true); thread.start(); } and aslong as this is running, my game is rendering and updating.

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  • Loading images in XNA 4.0; "Cannot Open File" Problems

    - by user32623
    Okay, I'm writing a game in C#/XNA 4.0 and am utterly stumped at my current juncture: Sprite animation. I understand how it works and have all the code in place, but my ContentLoader won't open my file... Basically, my directory looks like this: //WindowsGame1 - "Game1.cs" - //Classes - "NPC.cs" - Content Reference - //Images - "Monster.png" Inside my NPC class, I have all the essential drawing functions, i.e. LoadContent, Draw, Update. And I can get the game to find the correct file and attempt to open it, but when it tries, it throws an exception and tells me it can't open the file. This is how my code in my NPC class looks: Texture2D NPCImage; Vector2 NPCPosition; Animation NPCAnimation = new Animation(); public void Initialize() { NPCAnimation.Initialize(NPCPosition, new Vector2(4, 4)); } public void LoadContent(ContentManager Content) { NPCImage = Content.Load<Texture2D>("_InsertImageFilePathHere_"); NPCAnimation.AnimationImage = NPCImage; } The rest of the code is irrelevant at this point because I can't even get the image to load. I think it might have to do with a directory problem, but I also know little to nothing about spriting or working with images or animations in my code. Any help is appreciated. Not sure if I provided enough information here, so let me know if more is needed! Also, what would be the correct way to direct that Content.Load to Monster.png given the current directory situation? Right now I just have it using the full path from the C:// drive. Thanks in advance!

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  • Weird bug in Visual Studio 11 Beta when running on Windows 8

    - by raccoon_tim
    With the Windows 8 Consumer Preview version out in the open and the Visual Studio 11 Beta also available, I’ve been putting some more effort into trying them both out. The first impression of the new Visual Studio 11 build was: Why doesn’t it work at all on Windows 8?! The issues I encountered were odd to say the least. Visual Studio did install correctly, which was a good sign, but when I started it, I was greeted with a multitude of popups each telling me that some package could not be loaded. So I clicked away for quite some time to finally be greeted by the new default visual style of Visual Studio. The next thing I wanted to do was start a new project so I pressed “New Project” and got the “Microsoft.VisualStudio.Dialogs.DialogInitializationException” exception. After some pondering and even submitting a bug report I found another already reported bug “http://connect.microsoft.com/VisualStudio/feedback/details/727578/vs-do-not-work-with-finnish-number-format-on-w8-64-bit”. It turns out that the dialog initialization failure has something to do with the packages no being loaded and following the presented workaround helped. The trick is to change the negative number sign to “-“ (U+002D) from the additional settings of your regional settings. This issue appears to have a wider reach than just Visual Studio as I heard at TechDays Finland 2012 that the same fix has to be made when using Hyper-V.

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  • Resource Acquisition is Initialization in C#

    - by codeWithoutFear
    Resource Acquisition Is Initialization (RAII) is a pattern I grew to love when working in C++.  It is perfectly suited for resource management such as matching all those pesky new's and delete's.  One of my goals was to limit the explicit deallocation statements I had to write.  Often these statements became victims of run-time control flow changes (i.e. exceptions, unhappy path) or development-time code refactoring. The beauty of RAII is realized by tying your resource creation (acquisition) to the construction (initialization) of a class instance.  Then bind the resource deallocation to the destruction of that instance.  That is well and good in a language with strong destructor semantics like C++, but languages like C# that run on garbage-collecting runtimes don't provide the same instance lifetime guarantees. Here is a class and sample that combines a few features of C# to provide an RAII-like solution: using System; namespace RAII { public class DisposableDelegate : IDisposable { private Action dispose; public DisposableDelegate(Action dispose) { if (dispose == null) { throw new ArgumentNullException("dispose"); } this.dispose = dispose; } public void Dispose() { if (this.dispose != null) { Action d = this.dispose; this.dispose = null; d(); } } } class Program { static void Main(string[] args) { Console.Out.WriteLine("Some resource allocated here."); using (new DisposableDelegate(() => Console.Out.WriteLine("Resource deallocated here."))) { Console.Out.WriteLine("Resource used here."); throw new InvalidOperationException("Test for resource leaks."); } } } } The output of this program is: Some resource allocated here. Resource used here. Unhandled Exception: System.InvalidOperationException: Test for resource leaks. at RAII.Program.Main(String[] args) in c:\Dev\RAII\RAII\Program.cs:line 40 Resource deallocated here. Code without fear! --Don

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  • Seperation of drawing and logic in games

    - by BFree
    I'm a developer that's just now starting to mess around with game development. I'm a .Net guy, so I've messed with XNA and am now playing around with Cocos2d for the iPhone. My question really is more general though. Let's say I'm building a simple Pong game. I'd have a Ball class and a Paddle class. Coming from the business world development, my first instinct is to not have any drawing or input handling code in either of these classes. //pseudo code class Ball { Vector2D position; Vector2D velocity; Color color; void Move(){} } Nothing in the ball class handles input, or deals with drawing. I'd then have another class, my Game class, or my Scene.m (in Cocos2D) which would new up the Ball, and during the game loop, it would manipulate the ball as needed. The thing is though, in many tutorials for both XNA and Cocos2D, I see a pattern like this: //pseudo code class Ball : SomeUpdatableComponent { Vector2D position; Vector2D velocity; Color color; void Update(){} void Draw(){} void HandleInput(){} } My question is, is this right? Is this the pattern that people use in game development? It somehow goes against everything I'm used to, to have my Ball class do everything. Furthermore, in this second example, where my Ball knows how to move around, how would I handle collision detection with the Paddle? Would the Ball need to have knowledge of the Paddle? In my first example, the Game class would have references to both the Ball and the Paddle, and then ship both of those off to some CollisionDetection manager or something, but how do I deal with the complexity of various components, if each individual component does everything themselves? (I hope I'm making sense.....)

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  • Is using SVN for development and CM a bad practice?

    - by GatorGuy
    I have a bit of experience with SVN as a pure programmer/developer. Within my company, however, we use SVN as our configuration management tool. I thought using SVN for development at the same time was OK since we could use branches and the trunk for dev, and tags for releases. To me, the tags were the CM part, and the branches/trunk were the dev part. Recently a person, who develops high level code (but outside of the "pure SW" group) mentioned that the existing philosophy (mixing SVN for dev and CM) was wrong... in his opinion. His reasoning is that he thinks the company's CM tool should always link to run-able SW (so branches would break this rule). He also mentioned that a CM tool shouldn't be a backup utility for daily or incremental commits. Finally, he doesn't like the idea of having to jump from revision 143 to 89 in order to get a working copy... and further that CM tools shouldn't allow reversion to a broken state. In general he wants to separate the CM and back-up/dev utilties that SVN offers. Honestly, I am new and the person with this perspective is one of seniority, experience, and success, so I want to field this dilemma with the stackoverflow userbase to see if his approach has merit. My question: Should SVN be purely used for development, and another tool for CM (or vice versa)? Why? If so, what tools would you suggest for this combo? Or do you think that integrating both CM and dev into SVN is the best approach? Why? Thanks.

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  • More efficient in range checking

    - by Mob
    I am going to use a specific example in my question, but overall it is pretty general. I use java and libgdx. I have a ship that moves through space. In space there is debris that the ship can tractor beam in and and harvest. Debris is stored in a list, and the object contains it own x and y values. So currently there is no way to to find the debris's location without first looking at the debris object. Now at any given time there can be a huge (1000+) amount of debris in space, and I figure that calculating the distance between the ship and every single piece of debris and comparing it to maximum tractor beam length is rather inefficient. I have thought of dividing space into sectors, and have each sector contain a list of every object in it. This way I could only check nearby sectors. However this essentially doubles memory for the list. (I would reference the same object so it wouldn't double overall. I am not CS major, but I doubt this would be hugely significant.) This also means anytime an object moves it has to calculate which sector it is in, again not a huge problem. I also don't know if I can use some sort of 2D MAP that uses x and y values as keys. But since I am using float locations this sounds more trouble than its worth. I am kind of new to programming games, and I imagined there would be some eloquent solution to this issue.

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  • Recommended formats to store bitmaps in memory?

    - by Geotarget
    I'm working with general purpose image rendering, and high-performance image processing, and so I need to know how to store bitmaps in-memory. (24bpp/32bpp, compressed/raw, etc) I'm not working with 3D graphics or DirectX / OpenGL rendering and so I don't need to use graphics card compatible bitmap formats. My questions: What is the "usual" or "normal" way to store bitmaps in memory? (in C++ engines/projects?) How to store bitmaps for high-performance algorithms, such that read/write times are the fastest? (fixed array? with/without padding? 24-bpp or 32-bpp?) How to store bitmaps for applications handling a lot of bitmap data, to minimize memory usage? (JPEG? or a faster [de]compression algorithm?) Some possible methods: Use a fixed packed 24-bpp or 32-bpp int[] array and simply access pixels using pointer access, all pixels are allocated in one continuous memory chunk (could be 1-10 MB) Use a form of "sparse" data storage so each line of the bitmap is allocated separately, reusing more memory and requiring smaller contiguous memory segments Store bitmaps in its compressed form (PNG, JPG, GIF, etc) and unpack only when its needed, reducing the amount of memory used. Delete the unpacked data if its not used for 10 secs.

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  • How should I approach learning programming languages?

    - by gcc
    I am a student of computer engineering. I have never done any programming before, and as you can understand, I don't know how to study it or how to make my own programs. My English is weak [edited for clarity - ed], and so if you don't like the choices I list, please feel free to provide others. How should I study? How should I learn programming languages? Study completely from a book. Don't study from a book, just try writing code. A mix of the two; study from a book, then try writing code. Study half the book, then write the code by hand on paper. Listed to the teacher, then try to solve general problems (those not from any specific chapter). I have send that question to stackoverflow before when I am at first year. Now, I want to construct webpage to guide fresh students by giving advise of yours and mines.Maybe, you wonder Why I want to construct webpage , I just want help the other student. I am giving a link to that question < http://stackoverflow.com/questions/3389465/how-should-i-study-programming-languagess If you have other advice, feel free. EDIT: This web cite, I think , is constructed to share member's life experience and also I know these experiences is valuable . So I have no right to want your opinion, But I want your opinion / experience even if you think it is not so helpful to other

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  • Oracle Buys BigMachines - Adds Leading Configure, Price and Quote (CPQ) Cloud to the Oracle Cloud to Enable Smarter Selling

    - by Richard Lefebvre
    News Facts Oracle today announced that it has entered into an agreement to acquire BigMachines, a leading cloud-based Configure, Price and Quote (CPQ) solution provider. BigMachines’ CPQ Cloud accelerates the conversion of sales opportunities into revenue by automating the sales order process with guided selling, dynamic pricing, and an easy-to-use workflow approval process, accessible anywhere, on any device. Companies that use sales automation technology often rely on manual, cumbersome and disconnected processes to convert opportunities into orders. This creates errors, adds costs, delays revenue, and degrades the customer experience. BigMachines’ CPQ cloud extends sales automation to include the creation of an optimal quote, which enables sales personnel to easily configure and price complex products, select the best options, promotions and deal terms, and include up sell and renewals, all using automated workflows. In combination with Oracle’s enterprise-grade cloud solutions, including Marketing, Sales, Social, Commerce and Service Clouds, Oracle and BigMachines will create an end-to-end smarter selling cloud solution so sales personnel are more productive, customers are more satisfied, and companies grow revenue faster. More information on this announcement can be found at http://www.oracle.com/bigmachines Supporting Quotes “The fundamental goals of smarter selling are to provide sales teams with the information, access, and insights they need to maximize revenue opportunities and execute on all phases of the sales cycle,” said Thomas Kurian, Executive Vice President, Oracle Development. “By adding BigMachines’ CPQ Cloud to the Oracle Cloud, companies will be able to drive more revenue and increase customer satisfaction with a seamlessly integrated process across marketing and sales, pricing and quoting, and fulfillment and service.” “BigMachines has developed leading CPQ solutions that serve companies of all sizes across multiple industries,” said David Bonnette, BigMachines’ CEO. “Together with Oracle, we expect to provide a complete cloud solution to manage sales processes and deliver exceptional customer experiences.” Supporting Resources About Oracle and BigMachines General Presentation Customer and Partner Letter FAQ

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  • Why is Python used for high-performance/scientific computing (but Ruby isn't)?

    - by Cyclops
    There's a quote from a PyCon 2011 talk that goes: At least in our shop (Argonne National Laboratory) we have three accepted languages for scientific computing. In this order they are C/C++, Fortran in all its dialects, and Python. You’ll notice the absolute and total lack of Ruby, Perl, Java. It was in the more general context of high-performance computing. Granted the quote is only from one shop, but another question about languages for HPC, also lists Python as one to learn (and not Ruby). Now, I can understand C/C++ and Fortran being used in that problem-space (and Perl/Java not being used). But I'm surprised that there would be a major difference in Python and Ruby use for HPC, given that they are fairly similar. (Note - I'm a fan of Python, but have nothing against Ruby). Is there some specific reason why the one language took off? Is it about the libraries available? Some specific language features? The community? Or maybe just historical contigency, and it could have gone the other way?

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  • Web hosting company basically forces me to use their domain name [closed]

    - by Jinx
    I've recently stumbled upon an unusual problem with one of hosting companies called giga-international.com. Anyway, I've ordered com.hr domain from Croatian domain name registration company, and my client insisted on using this host provider as couple of his friends already are hosted with them. I thought something was fishy when the first result on Google for Giga International was this little forum rant instead of their webpage. When I was checking their services they listed many features etc... space available, bandwidth etc. I just wanted to check how much ram do I get for my PHP scripts so I emailed them, and they told me that was company secret. Seriously? Anyway, since my client still insisted on hosting with them I've bought their Webspace package. During registration I had to choose free domain name because I couldn't advance registration without it. Nowhere was said, not even in general terms and conditions that I wouldn't be able to change that domain name. At least not for double the price of domain name per year. They said I can either move my domain name over to them (and pay them domain registration), or pay them 1 Euro per month for managing a DNS entry. On any previous hosting solution I was able to manage my domain names just by pointing my domain to their name servers, and this is something completely new and absurd for me. They also said that usual approach is not possible because of security and hardware limitations. I'd like to know what you guys think about this case, and should I report, and where should I report this case. In short. They forced me to register free domain name which doesn't suit my needs in order to register for their webspace package, and refuse to change domain name for my account until I either transfer domain to them or pay them DNS management which costs double the price of the domain name per year.

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  • How to deal with elimination of duplicate logic vs. cost of complexity increase?

    - by Gabriel
    I just wrote some code that is very representative of a recurring theme (in my coding world lately): repeated logic leads to an instinct to eliminate duplication which results in something that is more complex the tradeoff seems wrong to me (the examples of the negative side aren't worth posting - but this is probably the 20th console utility I've written in the past 12 months). I'm curious if I'm missing some techniques or if this is really just on of those "experience tells you when to do what" type of issues. Here's the code... I'm tempted to leave it as is, even though there will be about 20 of those if-blocks when I'm done. static void Main(string[] sargs) { try { var urls = new DirectTrackRestUrls(); var restCall = new DirectTrackRestCall(); var logger = new ConsoleLogger(); Args args = (Args)Enum.Parse(typeof(Args), string.Join(",", sargs)); if (args.HasFlag(Args.Campaigns)) { var getter = new ResourceGetter(logger, urls.ListAdvertisers, restCall); restCall.UriVariables.Add("access_id", 1); getter.GotResource += new ResourceGetter.GotResourceEventHandler(getter_GotResource); getter.GetResources(); SaveResources(); } if (args.HasFlag(Args.Advertisers)) { var getter = new ResourceGetter(logger, urls.ListAdvertisers, restCall); restCall.UriVariables.Add("access_id", 1); getter.GotResource += new ResourceGetter.GotResourceEventHandler(getter_GotResource); getter.GetResources(); SaveResources(); } if (args.HasFlag(Args.CampaignGroups)) { var getter = new ResourceGetter(logger, urls.ListCampaignGroups, restCall); getter.GotResource += new ResourceGetter.GotResourceEventHandler(getter_GotResource); getter.GetResources(); SaveResources(); } } catch (Exception e) { Console.WriteLine(e.InnerException); Console.WriteLine(e.StackTrace); }

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  • Why is quicksort better than other sorting algorithms in practice?

    - by Raphael
    This is a repost of a question on cs.SE by Janoma. Full credits and spoils to him or cs.SE. In a standard algorithms course we are taught that quicksort is O(n log n) on average and O(n²) in the worst case. At the same time, other sorting algorithms are studied which are O(n log n) in the worst case (like mergesort and heapsort), and even linear time in the best case (like bubblesort) but with some additional needs of memory. After a quick glance at some more running times it is natural to say that quicksort should not be as efficient as others. Also, consider that students learn in basic programming courses that recursion is not really good in general because it could use too much memory, etc. Therefore (and even though this is not a real argument), this gives the idea that quicksort might not be really good because it is a recursive algorithm. Why, then, does quicksort outperform other sorting algorithms in practice? Does it have to do with the structure of real-world data? Does it have to do with the way memory works in computers? I know that some memories are way faster than others, but I don't know if that's the real reason for this counter-intuitive performance (when compared to theoretical estimates).

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  • Blatant copyright theft

    - by Tom Gullen
    Found a user on the forum trying to solicit business for his website, a good user reported it and I checked the website out. Firstly and most dangerously it's attempting to sell our original software, which is open source. Our open source software is around 15mb big and he's serving a 50mb download and trying to sell it for $20. He's also stolen our CSS/images/site design in general which is all custom built. I attempted to open reasonable discussion with him, and he responded promptly saying he would remove offending materials if he could just have 3 days to sort it out which I accepted. I'm not sure what his plan was because everything on that site is offending material. Anyway he messaged back saying the site was offline, and it was, but it went back online shortly afterwards. It's pretty sickening that someone is selling open source work as their own, (the site about us page references him as the sole developer etc etc, it's unbelievable to read it). I want to shut it down, what are my options? I'm going to contact his domain registrar, web host, and Paypal (that's how he's selling the program). Any other ideas?

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  • New: Online NetBeans 8 Crash Course

    - by Geertjan
    On Twitter today I came across an announcement for a brand new on-line course in NetBeans 8. Since NetBeans 8 has been released during the past few months, the course is really very new. Go here to get there directly: https://www.video2brain.com/de/videotraining/netbeans-ide-8-0-crashkurs Here's the general idea. As you can see, the course is in German. With my basic understanding of German, I've had no problem in following the course. The trainer speaks clearly and slowly and everything is very well structured. The course covers all the basics of NetBeans IDE. From getting set up to using all the key features. The quality of the videos is great and the content is clear and informative. Once you've bought the course, all the lessons are unlocked. As you can see, they're all quite short and there's really a lot of content, didn't all fit into the screenshot: Quite some work must have gone into this. Here's one of the free lessons in the course, to give an idea of what you'll get: https://www.video2brain.com/de/tutorial/texte-internationalisieren This one is also free: https://www.video2brain.com/de/tutorial/eclipse-projekt-importieren I highly recommend this course especially if you're switching, or thinking about switching, from a different IDE and want to get a thorough overview of all the features that NetBeans IDE provides. Everything in the course is done within NetBeans, which means no slides, just code. You get to see the workflow of all the standard tasks and, for these purposes, the course does a really great job.

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  • Storage of leftover values in a situation of having to round down

    - by jt0dd
    I'm writing an app (client and server side) where the number of sales required by each employee must be kept track of in round-number form. Each month, the employees are required to sell a certain number, and this app needs to keep track of how many sales must be made for each 12 hour interval during the work week. Because I have to round the values down to a whole number, I must keep track of leftovers in the rounding process and ensure that they are always carried over. My method must ensure the storage of the leftover value even when client and server side crash, restart, close, etc. Right now, I'm working on doing this by storing the leftovers in a field in the user's account row in the database each time a value is rounded, reading the stored value, removing any portion that is used (when a whole number is reached, most of the leftover is used up), and storing the new value. This practice seems weird because while the leftovers are calculated on the client side, it's the same number for each employee, and every employee using the app is storing a copy of the same leftover data. Alternatively, I could have all clients store the data at once into the same data field on a general table, but this is just as weird. Is there a better way that this can be handled or is my method correct?

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  • Should a software developer get a yearly equipment budget?

    - by CrazyDart
    I am looking at a new position with a new company. I have talked to some people in the past (in general, not at this company) that they had been given a yearly budget to buy new computer stuff to keep up to date. Now why I feel this question is worth asking here is that Joel comes right out and says an employer should pay for the best equipment money can buy... within reason of course. From The Joel Test: 12 Steps to Better Code 9. Do you use the best tools money can buy? Writing code in a compiled language is one of the last things that still can't be done instantly on a garden variety home computer... Top notch development teams don't torture their programmers. Even minor frustrations caused by using underpowered tools add up, making programmers grumpy and unhappy. And a grumpy programmer is an unproductive programmer... Does anyone know if the industry has such a standard to offer an allowance or budget? I have never worked for a company like this, but I am thinking I should toss this in the ring for negotiations. Seems reasonable. How do bigger companies like MS, Google, and Apple handle this? If you say yes, give a range... I have been told numbers from $5k to $10k. Seems high to me, but hey I would gladly take it.

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  • Impact of Server Failure on Coherence Request Processing

    - by jpurdy
    Requests against a given cache server may be temporarily blocked for several seconds following the failure of other cluster members. This may cause issues for applications that can not tolerate multi-second response times even during failover processing (ignoring for the moment that in practice there are a variety of issues that make such absolute guarantees challenging even when there are no server failures). In general, Coherence is designed around the principle that failures in one member should not affect the rest of the cluster if at all possible. However, it's obvious that if that failed member was managing a piece of state that another member depends on, the second member will need to wait until a new member assumes responsibility for managing that state. This transfer of responsibility is (as of Coherence 3.7) performed by the primary service thread for each cache service. The finest possible granularity for transferring responsibility is a single partition. So the question becomes how to minimize the time spent processing each partition. Here are some optimizations that may reduce this period: Reduce the size of each partition (by increasing the partition count) Increase the number of JVMs across the cluster (increasing the total number of primary service threads) Increase the number of CPUs across the cluster (making sure that each JVM has a CPU core when needed) Re-evaluate the set of configured indexes (as these will need to be rebuilt when a partition moves) Make sure that the backing map is as fast as possible (in most cases this means running on-heap) Make sure that the cluster is running on hardware with fast CPU cores (since the partition processing is single-threaded) As always, proper testing is required to make sure that configuration changes have the desired effect (and also to quantify that effect).

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  • Looking for job advice [closed]

    - by EntryLevelJavaDeveloper
    I am a software developer for a government agency in DC, and I have recently completed one year of employment. I am generally dissatisfied with my experiences here. I do not want to gripe too much, but I do not spend a lot of time doing actual development on projects. I am asked to do everything under the sun: write requirements, review specs, test, attend random meetings, but actual coding makes up a small fraction of my time. The coding itself is fairly straightforward and simple so it feels like I am not growing from my experiences. I am not tasked with more challenging work, and I find the experiences are not rewarding. If I had a stronger resume/more work experience, I'd leave the position immediately but combined with the present economy, I am hesitant to leave. I have several questions: Does anybody have experiences like this? How did you make the most of it? I am currently doing some side projects, making simple webpages for people, but aside from that, and open source projects, what other things are out there? What are general benchmarks for a developer after one year of professional experience? What should I be expected to know/do? I am outsider (coming from a math/science background) so I do not know what exactly I should know/do. Is it possible to obtain a mentorship with a mid/senior developer to learn? If so, how can I go about making contacts in the DC area?

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  • How Do Computers Work? [closed]

    - by Rob P.
    This is almost embarrassing ask...I have a degree in Computer Science (and a second one in progress). I've worked as a full-time .NET Developer for nearly five years. I generally seem competent at what I do. But I Don't Know How Computers Work! Please, bare with me for a second. A quick Google of 'How a Computer Works' will yield lots and lots of results, but I struggled to find one that really answered what I'm looking for. I realize this is a huge, huge question, so really, if you can just give me some keywords or some direction. I know there are components....the power supply, the motherboard, ram, CPU, etc...and I get the 'general idea' of what they do. But I really don't understand how you go from a line of code like Console.Readline() in .NET (or Java or C++) and have it actually do stuff. Sure, I'm vaguely aware of MSIL (in the case of .NET), and that some magic happens with the JIT compiler and it turns into native code (I think). I'm told Java is similar, and C++ cuts out the middle step. I've done some mainframe assembly, it was a few years back now. I remember there were some instructions and some CPU registers, and I wrote code....and then some magic happened....and my program would work (or crash). From what I understand, an 'Emulator' would simulate what happens when you call an instruction and it would update the CPU registers; but what makes those instructions work the way they do? Does this turn into an Electronics question and not a 'Computer' question? I'm guessing there isn't any practical reason for me to understand this, but I feel like I should be able to. (Yes, this is what happens when you spend a day with a small child. It takes them about 10 minutes and five iterations of asking 'Why?' for you to realize how much you don't know)

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  • How do I stop video tearing? (Nvidia prop driver, non-compositing window manager)

    - by Chan-Ho Suh
    I have that problem which seemingly afflicts many using the proprietary Nvidia driver: Video tearing: fine horizontal lines (usually near the top of my display) when there is a lot of panning or action in the video. (Note: switching back to the default nouveau driver is not an option, as its seemingly nonexistent power-management drains my battery several times faster) I've tried Totem, Parole, and VLC, and tearing occurs with all of them. The best result has been to use X11 output in VLC, but there is still tearing with relatively moderate action. Hardware: MacBook Air 3,2 -- which has an Nvidia GeForce 320M. There are two common fixes for tearing with Nvidia prop drivers: Turn off compositing, since Nvidia proprietary drivers don't usually play nice with compositing window managers on Linux (Compiz is an exception I'm aware of). But I use an extremely lightweight window manager (Awesome window manager) which is not even capable of compositing (or any cool effects). I also have this problem in Xfce, where I have compositing disabled. Enabling sync to VBlank. To enable this, I set the option in nvidia-settings and then autostart it as nvidia-settings -l with my other autostart programs. This seems to work, because when I run glxgears, I get: $ glxgears Running synchronized to the vertical refresh. The framerate should be approximately the same as the monitor refresh rate. 303 frames in 5.0 seconds = 60.500 FPS 300 frames in 5.0 seconds = 59.992 FPS And when I check the refresh rate using nvidia-settings: $ nvidia-settings -q RefreshRate Attribute 'RefreshRate' (wampum:0.0; display device: DFP-2): 60.00 Hz. All this suggests sync to VBlank is enabled. As I understand it, this is precisely designed to stop tearing, and a lot of people's problem is even getting something like glxgears to output the correct info. I don't understand why it's not working for me. xorg.conf: http://paste.ubuntu.com/992056/ Example of observed tearing::

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  • Hello!

    - by barryoreilly
    After many months of deliberating I have finally gotten around to starting this blog! The reason for doing this is the large number of half finished articles lying around on my hard disk, unpublished and unloved. These articles have been of huge benefit to me, and have been written in an attempt to consolidate my own thinking, in order to help me structure my thoughts and ideas as I have tried to digest new ideas and understand abstract theories. It is my hope that by tidying up these articles and publishing them here that I can continue this learning process by getting feedback on the ideas from within the developer community. i have worked with .NET for 8 years now, and have worked with ASP.NET, SQL Server, Windows programming as well as general network administration. Since 2004 my focus has been on integration, web services, and more often than not Biztalk Server. The last two years have seen me focus on SOA and WCF, and the Managed Services Engine, so this is probably where the main focus of the blog will to start with, but there are so many fun things to play with these days that i have no idea where it will end up.....   Barry

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  • Is this the correct approach to an OOP design structure in php?

    - by Silver89
    I'm converting a procedural based site to an OOP design to allow more easily manageable code in the future and so far have created the following structure: /classes /templates index.php With these classes: ConnectDB Games System User User -Moderator User -Administrator In the index.php file I have code that detects if any $_GET values are posted to determine on which page content to build (it's early so there's only one example and no default): function __autoload($className) { require "classes/".strtolower($className).".class.php"; } $db = new Connect; $db->connect(); $user = new User(); if(isset($_GET['gameId'])) { System::buildGame($gameId); } This then runs the BuildGame function in the system class which looks like the following and then uses gets in the Game Class to return values, such as $game->getTitle() in the template file template/play.php: function buildGame($gameId){ $game = new Game($gameId); $game->setRatio(900, 600); require 'templates/play.php'; } I also have .htaccess so that actual game page url works instead of passing the parameters to index.php Are there any major errors of how I'm setting this up or do I have the general idea of OOP correct?

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