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• Bios Memory settings and Virtualization + Ubuntu (Unofficial Answers Welcome) [closed]

  - by TardisGuy

  Attempting to optimize my (Main Windowless) Ubuntu system for my uses I will detail questions below, I understand this might be the wrong place to ask these questions. If so, my apologies and I thank you so much for your patience. Thanks to all the volenteers that have helped me learn ubuntu over the years (Since 5.10) This is a "short" list of questions I have been trying to figure out for some time. If you feel you can answer one but not another, that's already more than I could ask for. I have wrote this up in a format for easy navigation to important points Hopefully to less annoy your eyes. You're welcome :) or i'm sorry i annoy you. :( If you would be so kind, Please format answers as follows: question 1: _ _ _ _ _ or question 1-a: _ _ _ _ _ If you want to simply link me to relevant information, rather than type up something really detailed; that would be more than awesome! Memory Specific Questions Goal: Maximizing memory bandwith to better perform in Virtualization, and Large file compression. (Possible conflict?) Ganged vs Unganged "which is better?"** is relative, i know. But what about ganged vs unganged - With or without Bank/channel interleaving? a: Speculation - If i understand correctly, "channel interleaving has something to do with using both channels to read or write in a kind of "striping" pattern, as opposed to a standard half duplex operation.(probably wrong) but wouldn't ganged channels make this irrelevant? Memory Interleaving(bank). Does it have a down side? Does it require a ratio of clocks? (If I run 4x4gig ddr3) a. If im reading correctly(trying to learn), this is designed to spread operations between latency cycles to work around the higher latency of "normal" operation. b. However it seems to me that it has to be: divisible by fractions of a master clock? So if i run memory at 1333mhz, then the mean between 2 (physical) banks would operate every (roughly) 600Mhz? Warning! Possibly utter nonsense: (1333/2 interleaving to act like 1 memory module per 2 sticks of a total of 4 sticks, meaning 2x channels@4) c. which makes me wonder if there would be left over clock cycles the system would have to... "truncate/balance" or something? But I'm certain theres a feature somewhere i don't understand. Virtualization Questions AMD-V - Option of IOMMU Turned it on, why do i have extra option of "64MB"? If IOMMU is on, but "64MB" is "disabled", Is it on? (have scoured google, I still dont know) a. I think i understand that its supposed to (kind of) "set aside" a part of ram to act as a faster interactive zone for "stuff" (usb, Graphics, and... what?) b. I am using Nvidia graphics on AMD (Used kernel option "iommu=pt iommu=1, pt "passthrough"? No idea what they do, found it on google to solve boot up issue) c. Will this option help me use low latency sound hardware, like my midi keyboard? Can you recommend any additional tweaks? a. sysctl settings? b. swap settings? Grats, youve reached the end. Thanks for Reading.

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• Dependency Injection Introduction

  - by MarkPearl

  I recently was going over a great book called “Dependency Injection in .Net” by Mark Seeman. So far I have really enjoyed the book and would recommend anyone looking to get into DI to give it a read. Today I thought I would blog about the first example Mark gives in his book to illustrate some of the benefits that DI provides. The ones he lists are Late binding Extensibility Parallel Development Maintainability Testability To illustrate some of these benefits he gives a HelloWorld example using DI that illustrates some of the basic principles. It goes something like this… class Program { static void Main(string[] args) { var writer = new ConsoleMessageWriter(); var salutation = new Salutation(writer); salutation.Exclaim(); Console.ReadLine(); } } public interface IMessageWriter { void Write(string message); } public class ConsoleMessageWriter : IMessageWriter { public void Write(string message) { Console.WriteLine(message); } } public class Salutation { private readonly IMessageWriter _writer; public Salutation(IMessageWriter writer) { _writer = writer; } public void Exclaim() { _writer.Write("Hello World"); } }   If you had asked me a few years ago if I had thought this was a good approach to solving the HelloWorld problem I would have resounded “No”. How could the above be better than the following…. class Program { static void Main(string[] args) { Console.WriteLine("Hello World"); Console.ReadLine(); } }  Today, my mind-set has changed because of the pain of past programs. So often we can look at a small snippet of code and make judgements when we need to keep in mind that we will most probably be implementing these patterns in projects with hundreds of thousands of lines of code and in projects that we have tests that we don’t want to break and that’s where the first solution outshines the latter. Let’s see if the first example achieves some of the outcomes that were listed as benefits of DI. Could I test the first solution easily? Yes… We could write something like the following using NUnit and RhinoMocks… [TestFixture] public class SalutationTests { [Test] public void ExclaimWillWriteCorrectMessageToMessageWriter() { var writerMock = MockRepository.GenerateMock<IMessageWriter>(); var sut = new Salutation(writerMock); sut.Exclaim(); writerMock.AssertWasCalled(x => x.Write("Hello World")); } }   This would test the existing code fine. Let’s say we then wanted to extend the original solution so that we had a secure message writer. We could write a class like the following… public class SecureMessageWriter : IMessageWriter { private readonly IMessageWriter _writer; private readonly string _secretPassword; public SecureMessageWriter(IMessageWriter writer, string secretPassword) { _writer = writer; _secretPassword = secretPassword; } public void Write(string message) { if (_secretPassword == "Mark") { _writer.Write(message); } else { _writer.Write("Unauthenticated"); } } }   And then extend our implementation of the program as follows… class Program { static void Main(string[] args) { var writer = new SecureMessageWriter(new ConsoleMessageWriter(), "Mark"); var salutation = new Salutation(writer); salutation.Exclaim(); Console.ReadLine(); } }   Our application has now been successfully extended and yet we did very little code change. In addition, our existing tests did not break and we would just need add tests for the extended functionality. Would this approach allow parallel development? Well, I am in two camps on parallel development but with some planning ahead of time it would allow for it as you would simply need to decide on the interface signature and could then have teams develop different sections programming to that interface. So,this was really just a quick intro to some of the basic concepts of DI that Mark introduces very successfully in his book. I am hoping to blog about this further as I continue through the book to list some of the more complex implementations of containers.

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• Trouble rotating viewplatform in Java3D [closed]

  - by user29163

  I have just started with Java3D programming. I thought I had built up some basic intuition about how the scene graph works, but something that should work, does not work. I made a simple program for rotating a pyramid around the y-axis. This was done just by adding a RotationInterpolator R to the TransformGroup above the pyramid. Then I thought hey, can I now remove the RotationInterpolator from this TransformGroup, then add it to the TransformGroup above my ViewPlatform leaf. This should work if I have understood how things work. Adding the RotationInterpolator to this TransformGroup, should make the children of this TransformGroup rotate, and the ViewingPlatform is a child of the TransformGroup. Any ideas on where my reasoning is flawed? Here is the code for setting up the universe, and the view branchgroup. import java.awt.*; import java.awt.event.*; import javax.media.j3d.*; import javax.vecmath.*; public class UniverseBuilder { // User-specified canvas Canvas3D canvas; // Scene graph elements to which the user may want access VirtualUniverse universe; Locale locale; TransformGroup vpTrans; View view; public UniverseBuilder(Canvas3D c) { this.canvas = c; // Establish a virtual universe that has a single // hi-res Locale universe = new VirtualUniverse(); locale = new Locale(universe); // Create a PhysicalBody and PhysicalEnvironment object PhysicalBody body = new PhysicalBody(); PhysicalEnvironment environment = new PhysicalEnvironment(); // Create a View and attach the Canvas3D and the physical // body and environment to the view. view = new View(); view.addCanvas3D(c); view.setPhysicalBody(body); view.setPhysicalEnvironment(environment); // Create a BranchGroup node for the view platform BranchGroup vpRoot = new BranchGroup(); // Create a ViewPlatform object, and its associated // TransformGroup object, and attach it to the root of the // subgraph. Attach the view to the view platform. Transform3D t = new Transform3D(); Transform3D s = new Transform3D(); t.set(new Vector3f(0.0f, 0.0f, 10.0f)); t.rotX(-Math.PI/4); s.set(new Vector3f(0.0f, 0.0f, 10.0f)); //forandre verdier her for å endre viewing position t.mul(s); ViewPlatform vp = new ViewPlatform(); vpTrans = new TransformGroup(t); vpTrans.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE); // Rotator stuff Transform3D yAxis = new Transform3D(); //yAxis.rotY(Math.PI/2); Alpha rotationAlpha = new Alpha( -1, Alpha.INCREASING_ENABLE, 0, 0,4000, 0, 0, 0, 0, 0); RotationInterpolator rotator = new RotationInterpolator( rotationAlpha, vpTrans, yAxis, 0.0f, (float) Math.PI*2.0f); RotationInterpolator rotator2 = new RotationInterpolator( rotationAlpha, vpTrans); BoundingSphere bounds = new BoundingSphere(new Point3d(0.0,0.0,0.0), 1000.0); rotator.setSchedulingBounds(bounds); vpTrans.addChild(rotator); vpTrans.addChild(vp); vpRoot.addChild(vpTrans); view.attachViewPlatform(vp); // Attach the branch graph to the universe, via the // Locale. The scene graph is now live! locale.addBranchGraph(vpRoot); } public void addBranchGraph(BranchGroup bg) { locale.addBranchGraph(bg); } }

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• Class design issue

  - by user2865206

  I'm new to OOP and a lot of times I become stumped in situations similar to this example: Task: Generate an XML document that contains information about a person. Assume the information is readily available in a database. Here is an example of the structure: <Person> <Name>John Doe</Name> <Age>21</Age> <Address> <Street>100 Main St.</Street> <City>Sylvania</City> <State>OH</State> </Address> <Relatives> <Parents> <Mother> <Name>Jane Doe</Name> </Mother> <Father> <Name>John Doe Sr.</Name> </Father> </Parents> <Siblings> <Brother> <Name>Jeff Doe</Name> </Brother> <Brother> <Name>Steven Doe</Name> </Brother> </Siblings> </Relatives> </Person> Ok lets create a class for each tag (ie: Person, Name, Age, Address) Lets assume each class is only responsible for itself and the elements directly contained Each class will know (have defined by default) the classes that are directly contained within them Each class will have a process() function that will add itself and its childeren to the XML document we are creating When a child is drawn, as in the previous line, we will have them call process() as well Now we are in a recursive loop where each object draws their childeren until all are drawn But what if only some of the tags need to be drawn, and the rest are optional? Some are optional based on if the data exists (if we have it, we must draw it), and some are optional based on the preferences of the user generating the document How do we make sure each object has the data it needs to draw itself and it's childeren? We can pass down a massive array through every object, but that seems shitty doesnt it? We could have each object query the database for it, but thats a lot of queries, and how does it know what it's query is? What if we want to get rid of a tag later? There is no way to reference them. I've been thinking about this for 20 hours now. I feel like I am misunderstanding a design principle or am just approaching this all wrong. How would you go about programming something like this? I suppose this problem could apply to any senario where there are classes that create other classes, but the classes created need information to run. How do I get the information to them in a way that doesn't seem fucky? Thanks for all of your time, this has been kicking my ass.

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• Does *every* project benefit from written specifications?

  - by nikie

  I know this is holy war territory, so please read the question to the end before answering. There are many cases where written specifications make a lot of sense. For example, if you're a contractor and you want to get paid, you need written specs. If you're working in a team with 20 persons, you need written specs. If you're writing a programming language compiler or interpreter (and it's not perl), you'll usually write a formal specification. I don't doubt that there are many more cases where written specifications are a really good idea. I just think that there are cases where there's so little benefit in written specs, that it doesn't outweigh the costs of writing and maintaining them. EDIT: The close votes say that "it is difficult to say what is asked here", so let me clarify: The usefulness of written, detailed specifications is often claimed like a dogma. (If you want examples, look at the comments.) But I don't see the use of them for the kind of development I'm doing. So what is asked here is: How would written specifications help me? Background information: I work for a small company that's developing vertical market software. If our product is easier to use and has better performance than the competition, it sells. If it's harder to use, even if it behaves 100% as the specification says, it doesn't sell. So there are no "external forces" for having written specs. The advantage would have to be somewhere in the development process. Now, I can see how frozen specifications would make a developer's life easier. But we'll never have frozen specs. If we see in the middle of development that feature X is not intuitive to use the way it's specified, then we can only choose between changing the specification or developing a product that won't sell. You'll probably ask by now: How do you know when you're done? Well, we're continually improving our product. The competition does the same. So (hopefully) we're never done. We keep improving the software, and when we reach a point when the benefits of the improvements we've added since the last release outweigh the costs of an update, we create a new release that is then tested, localized, documented and deployed. This also means that there's rarely any schedule pressure. Nobody has to do overtime to make a deadline. If the feature isn't done by the time we want to release the next version, it'll simply go into the next version. The next question might be: How do your developers know what they're supposed to implement? The answer is: They have a lot of domain knowledge. They know the customers business well enough, so a high-level description of the feature (or even just the problem that the customer needs solved) is enough to implement it. If it's not clear, the developer creates a few fake screens to get feedback from marketing/management or customers, but this is nowhere near the level of detail of actual specifications. This might be inefficient for larger teams, but for a small team with low turnover it works quite well. It has the additional benefit that the developer in question often comes up with a better solution than the person writing the specs might have. This question is already getting very long, but let me address one last point: Testing. Like I said in the beginning, if our software behaves 100% like the spec says, it still can be crap. In fact, if it's so unintuitive that you need a spec to know how to test it, it probably is crap. It makes sense to have fixed, written tests for some core functionality and for regression bugs, but again, this is nowhere near a full written spec of how the software should behave when. The main test is: hand the software to a user who doesn't know it yet and tell him to use the new feature X. If she can figure out how to use it and it works, it works.

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• Framework for Everything - Where to begin? [Longer post]

  - by SquaredSoft

  Back story of this question, feel free to skip down for the specific question Hello, I've been very interested in the idea of abstract programming the last few years. I've made about 30 attempts at creating a piece of software that is capable of almost anything you throw at it. I've undertook some attempts at this that have taken upwards of a year, while getting close, never releasing it beyond my compiler. This has been something I've always tried wrapping my head around, and something is always missing. With the title, I'm sure you're assuming, "Yes of course you noob! You can't account for everything!" To which I have to reply, "Why not?" To give you some background into what I'm talking about, this all started with doing maybe a shade of gray hat SEO software. I found myself constantly having to create similar, but slightly different sets of code. I've gone through as many iterations of way to communicate on http as the universe has particles. "How many times am I going to have to write this multi-threaded class?" is something I found myself asking a lot. Sure, I could create a class library, and just work with that, but I always felt I could optimize what I had, which often was a large undertaking and typically involved frequent use of the CRTL+A keyboard shortcut, mixed with the delete button. It dawned on me that it was time to invest in a plugin system. This would allow me to simply add snippets of code. as time went on, and I could subversion stuff out, and distribute small chunks of code, rather than something that encompasses only a specific function or design. This comes with its own complexity, of course, and by the time I had finished the software scope for this addition, it hit me that I would want to add to everything in the software, not just a new http method, or automation code for a specific website. Great, we're getting more abstract. However, the software that I have in my mind comes down to a quite a few questions regarding its execution. I have to have some parameters to what I am going to do. After writing what the perfect software would do in my mind, I came up with this as a list of requirements: Should be able to use networking A "Macro" or "Expression system" which would allow people to do something like : =First(=ParseToList(=GetUrl("http://www.google.com?q=helloworld!"), Template.Google)) Multithreaded Able to add UI elements through some type of XML -- People can make their own addons etc. Can use third party API through the plugins, such as Microsoft CRM, Exchange, etc. This would allow the software to essentially be used for everything. Really, any task you wish to automate, in a simple way. Making the UI was as also extremely hard. How do you do all of this? Its very difficult. So my question: With so many attempts at this, I'm out of ideas how to successfully complete this. I have a very specific idea in my mind, but I keep failing to execute it. I'm a self taught programmer. I've been doing it for years, and work professionally in it, but I've never encountered something that would be as complex and in-depth as a system which essentially does everything. Where would you start? What are the best practices for design? How can I avoid constantly having to go back and optimize my software. What can I do to generalize this and draw everything out to completion. These are things I struggle with. P.s., I'm using c# as my main language. I feel like in this example, I might be hitting the outer limit of the language, although, I don't know if that is the case, or if I'm just a bad programmer. Thanks for your time.

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• How to handle multi-processing of libraries which already spawn sub-processes?

  - by exhuma

  I am having some trouble coming up with a good solution to limit sub-processes in a script which uses a multi-processed library and the script itself is also multi-processed. Both, the library and script are modifiable by us. I believe the question is more about design than actual code, but for what it's worth, it's written in Python. The goal of the library is to hide implementation details of various internet routers. For that reason, the library has a "Proxy" factory method which takes the IP of a router as parameter. The factory then probes the device using a set of possible proxies. Usually, there is one proxy which immediately knows that is is able to send commands to this device. All others usually take some time to return (given a timeout). One thought was already to simply query the device for an identifier, and then select the proper proxy using that, but in order to do so, you would already need to know how to query the device. Abstracting this knowledge is one of the main purposes of the library, so that becomes a little bit of a "circular-requirement"/deadlock: To connect to a device, you need to know what proxy to use, and to know what proxy to create, you need to connect to a device. So probing the device is - as we can see - the best solution so far, apart from keeping a lookup-table somewhere. The library currently kills all remaining processes once a valid proxy has been found. And yes, there is always only one good proxy per device. Currently there are about 12 proxies. So if one create a proxy instance using the factory, 12 sub-processes are spawned. So far, this has been really useful and worked very well. But recently someone else wanted to use this library to "broadcast" a command to all devices. So he took the library, and wrote his own multi-processed script. This obviously spawned 12 * n processes where n is the number of IPs to which he broadcasted. This has given us two problems: The host on which the command was executed slowed down to a near halt. Aborting the script with CTRL+C ground the system to a total halt. Not even the hardware console responded anymore! This may be due to some Python strangeness which still needs to be investigated. Maybe related to http://bugs.python.org/issue8296 The big underlying question, is how to design a library which does multi-processing, so other applications which use this library and want to be multi-processed themselves do not run into system limitations. My first thought was to require a pool to be passed to the library, and execute all tasks in that pool. In that way, the person using the library has control over the usage of system resources. But my gut tells me that there must be a better solution. Disclaimer: My experience with multiprocessing is fairly limited. I have implemented a few straightforward which did not require access control to resources. So I have not yet any practical experience with semaphores or mutexes. p.s.: In the future, we may have enough information to do this without the probing. But the database which would contain the proper information is not yet operational. Also, the design about multiprocessing a multiprocessed library intrigues me :)

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• Free hosting solution for a very low-traffic website [duplicate]

  - by user966939

  This question already has an answer here: How to find web hosting that meets my requirements? 4 answers I run a very low-traffic website (about 40 users, basically all of which are daily active on the site). I don't see it changing anytime soon either, as there is no way to sign up on the site right now. Until now I have just been using a sub-directory on a friend's host (shared), to host the web site. But in only a few weeks from now, his subscription will end, and he has no plans on renewing it. So of course this means I'll have to move on to something else. But I don't think I'll find someone who'd be willing to share a... shared host with me again. And besides, the software used on that server is ancient (PHP 4.4.9 + MySQL 4.1.22). There's one obvious solution that comes to mind, I guess: choose a better host and pay for it myself. The problem here is that I have no real fixed income, as I'm only a student. So even if the pricing is dirt cheap, I just can't be certain I will be able to afford it, every single month, for... at least 2 years maybe? So I've looked at free hosting solutions instead. The least requirement I had was that it was completely free of ads. But no matter where I look, I always find something in a corner or two ("what can you expect from a free host?" - yeah I know, but I guess it was worth a shot). For example, on Byethost (one of the free hosts I tried), if you trigger a PHP error while error reporting is set to E_ALL, you will spawn some hidden ad... Besides Byethost, I've tried 000Webhost, x10Hosting, 2Freehosting/1Freehosting, Wink.ws, and they are only worse. Okay, I'm running low on ideas. But! What if I just hosted the site myself, on my own computer? That could work. I actually do have my computer on practically 24/7. But not really. Sometimes I need to reboot it, and sometimes we even have power outages. And what if the hardware needs an upgrade? It's not such a big deal for me if the site went down, because I know what's going on; but what about the users? If I do decide to host it myself, is there some way to show users an alternate page instead of them just seeing a generic "server not found" page in the browser when the site is not accessible? Or is there something I have been missing out on? Is there a different kind of "web hosting" solution out there that I haven't heard of? Here is what I'm really looking for: Free (as in, no costs) NO ads Bandwidth enough for a low-traffic forum with roughly 40 users (Semi-)Up-to-date PHP and MySQL (at least not older than a year) No standard (non-extension) PHP functions turned off - such as sleep() The mbstring extension is enabled Disk space: at least 5 MB At least one MySQL database Some bonus points would be: Max execution time of PHP scripts can be set Remote access to MySQL database What would be the best solution for me? Is there one?

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• Oracle Executive Strategy Brief: Enterprise-Grade Cloud Applications

  - by B Shashikumar

  Cloud Computing has clearly evolved into one of the dominant secular trends in the industry. Organizations are looking to the cloud to change how they buy and consume IT. And its no longer about just lower up-front costs. The cloud promises to deliver greater agility and free up resources to focus on innovation versus running and maintaining systems. But are organizations actually realizing these benefits? The full promise of cloud is not being realized by customers who entrust their business to multiple niche cloud providers. While almost 9 out of 10 companies  expect more IT agility with cloud, only 47% are actually getting it (Source: 2011 State of Cloud Survey by Symantec). These niche cloud customers have also seen the promises of lower costs, efficiency gains, improved security, and compliance go unfulfilled. Having one cloud provider for customer relationship management (CRM) and another for human capital management (HCM), and then trying to glue these proprietary systems together while integrating to a back-office financial system can add to complexity and long-term costs. Completing a business process or generating an integrated report is cumbersome, and leverages incomplete data. Why can’t niche cloud providers deliver on the full promise of cloud? It’s simple: you still need to complete business processes. You still need reporting that enables you to take action using data from multiple systems. You still have to comply with SOX and other industry regulations. These requirements don’t go away just because you deploy in the cloud. Delivering lower up-front costs by enabling customers to buy software as a service (SaaS) is the easy part. To get real value that lasts longer than your quarterly report, it’s important to realize the benefits of cloud without compromising on functionality and while having the right level of control and flexibility. This is the true promise of cloud. Oracle’s cloud strategy centers around delivering the benefits of cloud—without compromise. We uniquely empower our customers with complete solutions and choice. From the richest functionality to integrated reporting and great user experience. It’s all available in the cloud. And it works not just with other Oracle cloud applications, but with your existing Oracle and third-party systems as well. This helps protect your current investments and extend their value as you journey to the cloud. We’ve made the necessary investments not only in our applications but also in the underlying technology that makes it all run—from the platform down to the hardware and operating system. We make it all. And we’ve engineered it to work together and be highly optimized for our customers, in the cloud. With Oracle enterprise-grade cloud applications, you get the benefits of cloud plus more power, more choice, and more confidence. Read more about how you can realize the true advantage of Cloud with Oracle Enterprise-grade Cloud applications in the Oracle Executive Strategy Brief here.  You can also attend an Oracle Cloud Conference event at a city near you. Register here. 

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• Modernizr Rocks HTML5

  - by Laila

  HTML5 is a moving target.  At the moment, we don't know what will be in future versions.  In most circumstances, this really matters to the developer. When you're using Adobe Air, you can be reasonably sure what works, what is there, and what isn't, since you have a version of the browser built-in. With Metro, you can assume that you're going to be using at least IE 10.   If, however,  you are using HTML5 in a web application, then you are going to rely heavily on Feature Detection.  Feature-Detection is a collection of techniques that tell you, via JavaScript, whether the current browser has this feature natively implemented or not Feature Detection isn't just there for the esoteric stuff such as  Geo-location,  progress bars,  <canvas> support,  the new <input> types, Audio, Video, web workers or storage, but is required even for semantic markup, since old browsers make a pigs ear out of rendering this.  Feature detection can't rely just on reading the browser version and inferring from that what works. Instead, you must use JavaScript to check that an HTML5 feature is there before using it.  The problem with relying on the user-agent is that it takes a lot of historical data  to work out what version does what, and, anyway, the user-agent can be, and sometimes is, spoofed. The open-source library Modernizr  is just about the most essential  JavaScript library for anyone using HTML5, because it provides APIs to test for most of the CSS3 and HTML5 features before you use them, and is intelligent enough to alter semantic markup into 'legacy' 'markup  using shims  on page-load  for old browsers. It also allows you to check what video Codecs are installed for playing video. It also provides media queries  and conditional resource-loading (formerly YepNope.js.).  Generally, Modernizr gives you the choice of what you do about browsers that don't support the feature that you want. Often, the best choice is graceful degradation, but the resource-loading feature allows you to dynamically load JavaScript Shims to replace the standard API for missing or defective HTML5 functionality, called 'PolyFills'.  As the Modernizr site says 'Yes, not only can you use HTML5 today, but you can use it in the past, too!' The evolutionary progress of HTML5  requires a more defensive style of JavaScript programming where the programmer adopts a mindset of fearing the worst ( IE 6)  rather than assuming the best, whilst exploiting as many of the new HTML features as possible for the requirements of the site or HTML application.  Why would anyone want the distraction of developing their own techniques to do this when  Modernizr exists to do this for you? Laila

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• “Apparently, you signed a software services agreement without fully understanding it.”

  - by Dave Ballantyne

  I am not a lawyer. Let me say that again, I am not a lawyer. Todays Dilbert has prompted me to post about my recent experience with SqlServer licensing. I'm in the technical realm and rarely have much to do with purchasing and licensing.  I say “I need” , budget realities will state weather I actually get.  However, I do keep my ear to the ground and due to my community involvement, I know, or at least have an understanding of, some licensing restrictions. Due to a misunderstanding, Microsoft Licensing stated that we needed licenses for our standby servers.  I knew that that was not the case,  and a quick tweet confirmed this. So after composing an email stating exactly what the machines in question were used for ie Log shipped to and used in a disaster recover scenario only,  and posting several Technet articles to back this up, we saved 2 enterprise edition licences, a not inconsiderable cost. However during this discussion, I was made aware of another ‘legalese’ document that could completely override the referenced articles, and anything I knew, or thought i knew, about SqlServer licensing. Personally, I had no knowledge of this.  The “Purchase Use Rights” agreement would appear to be the volume licensing equivalent of the “End User License Agreement” , click throughs we all know and ignore.  Here is a direct quote from Microsoft licensing, when asked for clarification. “Thanks for your email. Just to give some background on the Product Use Rights (PUR), licenses acquired through volume licensing are bound by the most recent PUR at the time of license acquisition. The link for the current PUR and PUR archive is http://www.microsoft.com/licensing/about-licensing/product-licensing.aspx. Further to this, products acquired through boxed product or pre-installed on hardware (OEM) are bound by the End User License Agreement (EULA). The PUR will explain limitations, license requirements and rulings on areas like multiplexing, virtualization, processor licensing, etc. When an article will appear on a Microsoft site or blog describing the licensing of a product, it will be using the PUR as a base. Due to the writing style or language used by the person writing areas of the website or technical blogs, the PUR is what you should use as a rule and not any of the other media. The PUR is updated quarterly and will reference every product available at that time working on the latest version unless otherwise stated. The crux of this is that the PUR is written after extensive discussions between the different branches of Microsoft (legal, technical, etc) and the wording is then approved. This is not always the case for some pages explaining licensing as they are merely intended to advise and not subject to the intense scrutiny as the PUR.” So, exactly what does that mean ? My take :  This is a living document, “updated quarterly” , though presumably this could be done on a whim and a fancy.  It could state , you are only licensed if ,that during install you stand in a corner juggling and that photographic evidence is required. A plainly ridiculous demand but,  what else could it override or new requirements could it state that change your existing understanding of the product or your legal usage of it. As i say, im not a lawyer, but are you checking the PURA prior to purchase ?

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• Hyper-V for Developers Part 1 Internal Networks

  Over the last year, weve been working with Microsoft to build training and demo content for the next version of Office Communications Server code-named Microsoft Communications Server 14.  This involved building multi-server demo environments in Hyper-V, getting them running on demo servers which we took to TechEd, PDC, and other training events, and sometimes connecting the demo servers to the show networks at those events.  ITPro stuff that should scare the hell out of a developer! It can get ugly when I occasionally have to venture into ITPro land.  Lets leave it at that. Having gone through this process about 10 to 15 times in the last year, I finally have it down.  This blog series is my attempt to put all that knowledge in one place if anything, so I can find it somewhere when I need it again.  Ill start with the most simple scenario and then build on top of it in future blog posts. If youre an ITPro, please resist the urge to laugh at how trivial this is. Internal Hyper-V Networks Lets start simple.  An internal network is one that intended only for the virtual machines that are going to be on that network it enables them to communicate with each other. Create an Internal Network On your host machine, fire up the Hyper-V Manager and click the Virtual Network Manager in the Actions panel. Select Internal and leave all the other default values. Give the virtual network a name, and leave all the other default values. After the virtual network is created, open the Network and Sharing Center and click Change Adapter Settings to see the list of network connections. The only thing I recommend that you do is to give this connection a friendly label, e.g. Hyper-V Internal.  When you have multiple networks and virtual networks on the host machines, this helps group the networks so you can easily differentiate them from each other.  Otherwise, dont touch it, only bad things can happen. Connect the Virtual Machines to the Internal Network Im assuming that you have more than 1 virtual machine already configured in Hyper-V, for example a Domain Controller, and Exchange Server, and a SharePoint Server. What you need to do is basically plug in the network to the virtual machine.  In order to do this, the machine needs to have a virtual network adapter.  If the VM doesnt have a network adapter, open the VMs Settings and click Add Hardware in the left pane.  Choose the virtual network to which to bind the adapter to. If you already have a virtual network adapter on the VM, simply connect it to the virtual network. Assign IP Addresses to the Virtual Machines on the Internal Network Open the Network and Sharing Center on your VM, there should only be 1 network at this time.  Open the Properties of the connection, select Internet Protocol Version 4 (TCP/IPv4) and hit Properties. In this environment, Im assigning IP addresses as 192.168.0.xxx.  This particular VM has an IP address of 192.168.0.40 with a subnet mask of 255.255.255.0, and a DNS Server of 192.168.0.18.  DNS is running on the Domain Controller VM which has an IP address of 192.168.0.18. Repeat this process on every VM in your environment, obviously assigning a unique IP address to each.  In an environment with a domain controller, you should now be able to ping the machines from each other. What Next? After completing this process, heres what you still cannot do: Access the internet from any of the VMs Remote desktop to a VM from the host Remote desktop to a VM over the network In the next post, well take a look configuring an External network adapter on the virtual machines.  Well then build on top of that so that you can RDP into the VMs from the host machine and over the network.Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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• A* algorithm very slow

  - by Amaranth

  I have an programming a RTS game (I use XNA with C#). The pathfinding is working fine, except that when it has a lot of node to search in, there is a lag period of one or two seconds, it happens mainly when there is no path to the target destination, since it that situation there is more nodes to explore. I have the same problem when the path is shorter but selected more than 3 units (can't take the same path since the selected units can be in different part of the map). private List<NodeInfo> FindPath(Unit u, NodeInfo start, NodeInfo end) { Map map = GameInfo.GetInstance().GameMap; _nearestToTarget = start; start.MoveCost = 0; Vector2 endPosition = map.getTileByPos(end.X, end.Y).Position; //getTileByPos simply gets the tile in a 2D array with the X and Y indexes start.EstimatedRemainingCost = (int)(endPosition - map.getTileByPos(start.X, start.Y).Position).Length(); start.Parent = null; List<NodeInfo> openedNodes = new List<NodeInfo>(); ; List<NodeInfo> closedNodes = new List<NodeInfo>(); Point[] movements = GetMovements(u.UnitType); openedNodes.Add(start); while (!closedNodes.Contains(end) && openedNodes.Count > 0) { //Loop in nodes to find lowest cost NodeInfo currentNode = FindLowestCostOpenedNode(openedNodes); openedNodes.Remove(currentNode); closedNodes.Add(currentNode); Vector2 previousMouvement; if (currentNode.Parent == null) { previousMouvement = ConvertRotationToDirectionVector(u.Rotation); } else { previousMouvement = map.getTileByPos(currentNode.X, currentNode.Y).Position - map.getTileByPos(currentNode.Parent.X, currentNode.Parent.Y).Position; previousMouvement.Normalize(); } //For each neighbor foreach (Point movement in movements) { Point exploredGridPos = new Point(currentNode.X + movement.X, currentNode.Y + movement.Y); //Checks if valid move and checks if not if closed nodes list if (ValidNavigableNode(u.UnitType, new Point(currentNode.X, currentNode.Y), exploredGridPos) && !closedNodes.Contains(_gridMap[exploredGridPos.Y, exploredGridPos.X])) { NodeInfo exploredNode = _gridMap[exploredGridPos.Y, exploredGridPos.X]; Tile.TileType exploredTerrain = map.getTileByPos(exploredGridPos.X, exploredGridPos.Y).TerrainType; if(openedNodes.Contains(exploredNode)) { int newCost = currentNode.MoveCost + GetMoveCost(previousMouvement, movement, exploredTerrain); if (newCost < exploredNode.MoveCost) { exploredNode.Parent = currentNode; exploredNode.MoveCost = newCost; //Find nearest tile to the target (in case doesn't find path to target) //Only compares the node to the current nearest FindNearest(exploredNode); } } else { exploredNode.Parent = currentNode; exploredNode.MoveCost = currentNode.MoveCost + GetMoveCost(previousMouvement, movement, exploredTerrain); Vector2 exploredNodeWorldPos = map.getTileByPos(exploredGridPos.X, exploredGridPos.Y).Position; exploredNode.EstimatedRemainingCost = (int)(endPosition - exploredNodeWorldPos).Length(); //Find nearest tile to the target (in case doesn't find path to target) //Only compares the node to the current nearest FindNearest(exploredNode); openedNodes.Add(exploredNode); } } } } return closedNodes; } After that, I simply check if the end node is contained in the returned nodes. If so, I add the end node and each parent until I reach the start. If not, I add the nearestToTarget and each parent until I reach the start. I added a condition before calling FindPath so that only one unit can call a find path each frame (60 frame per second), but it makes no difference. I thought maybe I could solve this by allowing the find path to run in background while the game continues to run correctly, even if it takes a few frame (it is currently sequential sonce it is called in the update() of the unit if there's a target location but no path), but I don't really know how... I also though about sorting my opened nodes list by cost so I don't have to loop them, but I don't know if that would have an effect on the performance... Would there be other solutions? P.S. In the code, when I get the Move Cost, I check if the unit has to turn to perform the move, and the terrain type, nothing hard to do.

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• Obfuscation is not a panacea

  - by simonc

  So, you want to obfuscate your .NET application. My question to you is: Why? What are your aims when your obfuscate your application? To protect your IP & algorithms? Prevent crackers from breaking your licensing? Your boss says you need to? To give you a warm fuzzy feeling inside? Obfuscating code correctly can be tricky, it can break your app if applied incorrectly, it can cause problems down the line. Let me be clear - there are some very good reasons why you would want to obfuscate your .NET application. However, you shouldn't be obfuscating for the sake of obfuscating. Security through Obfuscation? Once your application has been installed on a user’s computer, you no longer control it. If they do not want to pay for your application, then nothing can stop them from cracking it, even if the time cost to them is much greater than the cost of actually paying for it. Some people will not pay for software, even if it takes them a month to crack a $30 app. And once it is cracked, there is nothing stopping them from putting the result up on the internet. There should be nothing suprising about this; there is no software protection available for general-purpose computers that cannot be cracked by a sufficiently determined attacker. Only by completely controlling the entire stack – software, hardware, and the internet connection, can you have even a chance to be uncrackable. And even then, someone somewhere will still have a go, and probably succeed. Even high-end cryptoprocessors have known vulnerabilities that can be exploited by someone with a scanning electron microscope and lots of free time. So, then, why use obfuscation? Well, the primary reason is to protect your IP. What obfuscation is very good at is hiding the overall structure of your program, so that it’s very hard to figure out what exactly the code is doing at any one time, what context it is running in, and how it fits in with the rest of the application; all of which you need to do to understand how the application operates. This is completely different to cracking an application, where you simply have to find a single toggle that determines whether the application is licensed or not, and flip it without the rest of the application noticing. However, again, there are limitations. An obfuscated application still has to run in the same way, and do the same thing, as the original unobfuscated application. This means that some of the protections applied to the obfuscated assembly have to be undone at runtime, else it would not run on the CLR and do the same thing. And, again, since we don’t control the environment the application is run on, there is nothing stopping a user from undoing those protections manually, and reversing some of the obfuscation. It’s a perpetual arms race, and it always will be. We have plenty of ideas lined about new protections, and the new protections added in SA 6.6 (method parent obfuscation and a new control flow obfuscation level) are specifically designed to be harder to reverse and reconstruct the original structure. So then, by all means, obfuscate your application if you want to protect the algorithms and what the application does. That’s what SmartAssembly is designed to do. But make sure you are clear what a .NET obfuscator can and cannot protect you against, and don’t expect your obfuscated application to be uncrackable. Someone, somewhere, will crack your application if they want to and they don’t have anything better to do with their time. The best we can do is dissuade the casual crackers and make it much more difficult for the serious ones. Cross posted from Simple Talk.

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• Multichannel Digital Engagement: Find Out How Your Organization Measures Up

  - by Michael Snow

  This article was originally published in the September 2013 Edition of the Oracle Information InDepth Newsletter ORACLE WEBCENTER EDITION Thanks to mobile and social technologies, interactive online experiences are now commonplace. Not only that, they give consumers more choices, influence, and control than ever before. So how can you make your organization stand out? The key building blocks for delivering exceptional cross-channel digital experiences are outlined below. Also, a new assessment tool is available to help you measure your organization's ability to deliver such experiences. A clearly defined digital strategy. The customer journey is growing increasingly complex, encompassing multiple touchpoints and channels. It used to be easy to map marketing efforts to specific offline channels; for example, a direct mail piece with an offer to visit a store for a discounted purchase. Now it is more difficult to cultivate and track such clear cause-and-effect relationships. To deliver an integrated digital experience in this more complex world, organizations need a clearly defined and comprehensive digital marketing strategy that is backed up by an integrated set of software, middleware, and hardware solutions. Strong support for business agility and speed-to-market. As both IT and marketing executives know, speed-to-market and business agility are key to competitive advantage. That means marketers need solutions to support the rapid implementation of online marketing initiatives—plus the flexibility to adapt quickly to a changing marketplace. And IT needs tools with the performance, scalability, and ease of integration to support marketing efforts. Both teams benefit when business users are empowered to implement marketing initiatives on their own, with minimal IT intervention. The ability to deliver relevant, personalized content. Delivering a one-size-fits-all online customer experience is no longer acceptable. Customers expect you to know who they are, including their preferences and past relationship with your brand. That means delivering the most relevant content from the moment a visitor enters your site. To make that happen, you need a powerful rules engine so that marketers and business users can easily define site visitor segments and deliver content accordingly. That includes both implicit targeting that is based on the user’s behavior, and explicit targeting that takes a user’s profile information into account. Ideally, the rules engine can also intelligently weight recommendations when multiple segments apply to a specific customer. Support for social interactivity. With the advent of Facebook and LinkedIn, visitors expect to participate in and contribute to your web presence—and share their experience on their own social networks. That requires easy incorporation of user-generated content such as comments, ratings, reviews, polls, and blogs; seamless integration with third-party social networking sites; and support for social login, which helps to remove barriers to social participation. The ability to deliver connected, multichannel experiences that include powerful, flexible mobile capabilities. By 2015, mobile usage is projected to surpass that of PCs and other wired devices. In other words, mobile is an essential element in delivering exceptional online customer experiences. This requires the creation and management of mobile experiences that are optimized for delivery to the thousands of different devices that are in use today. Just as important, organizations must be able to easily extend their traditional web presence to the mobile channel and deliver highly personalized and relevant multichannel marketing initiatives while also managing to minimize the time and effort required to manage mobile sites. Are you curious to know how your organization measures up when it comes to delivering an engaging, multichannel digital experience? If so, take this brief, 15-question online assessment and see how your organization scores in the areas of digital strategy, digital agility, relevance and personalization, social interactivity, and multichannel experience.

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• Entity System with C++ templates

  - by tommaisey

  I've been getting interested in the Entity/Component style of game programming, and I've come up with a design in C++ which I'd like a critique of. I decided to go with a fairly pure Entity system, where entities are simply an ID number. Components are stored in a series of vectors - one for each Component type. However, I didn't want to have to add boilerplate code for every new Component type I added to the game. Nor did I want to use macros to do this, which frankly scare me. So I've come up with a system based on templates and type hinting. But there are some potential issues I'd like to check before I spend ages writing this (I'm a slow coder!) All Components derive from a Component base class. This base class has a protected constructor, that takes a string parameter. When you write a new derived Component class, you must initialise the base with the name of your new class in a string. When you first instantiate a new DerivedComponent, it adds the string to a static hashmap inside Component mapped to a unique integer id. When you subsequently instantiate more Components of the same type, no action is taken. The result (I think) should be a static hashmap with the name of each class derived from Component that you instantiate at least once, mapped to a unique id, which can by obtained with the static method Component::getTypeId ("DerivedComponent"). Phew. The next important part is TypedComponentList<typename PropertyType>. This is basically just a wrapper to an std::vector<typename PropertyType> with some useful methods. It also contains a hashmap of entity ID numbers to slots in the array so we can find Components by their entity owner. Crucially TypedComponentList<> is derived from the non-template class ComponentList. This allows me to maintain a list of pointers to ComponentList in my main ComponentManager, which actually point to TypedComponentLists with different template parameters (sneaky). The Component manager has template functions such as: template <typename ComponentType> void addProperty (ComponentType& component, int componentTypeId, int entityId) and: template <typename ComponentType> TypedComponentList<ComponentType>* getComponentList (int componentTypeId) which deal with casting from ComponentList to the correct TypedComponentList for you. So to get a list of a particular type of Component you call: TypedComponentList<MyComponent>* list = componentManager.getComponentList<MyComponent> (Component::getTypeId("MyComponent")); Which I'll admit looks pretty ugly. Bad points of the design: If a user of the code writes a new Component class but supplies the wrong string to the base constructor, the whole system will fail. Each time a new Component is instantiated, we must check a hashed string to see if that component type has bee instantiated before. Will probably generate a lot of assembly because of the extensive use of templates. I don't know how well the compiler will be able to minimise this. You could consider the whole system a bit complex - perhaps premature optimisation? But I want to use this code again and again, so I want it to be performant. Good points of the design: Components are stored in typed vectors but they can also be found by using their entity owner id as a hash. This means we can iterate them fast, and minimise cache misses, but also skip straight to the component we need if necessary. We can freely add Components of different types to the system without having to add and manage new Component vectors by hand. What do you think? Do the good points outweigh the bad?

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• XNA - 3D AABB collision detection and response

  - by fastinvsqrt

  I've been fiddling around with 3D AABB collision in my voxel engine for the last couple of days, and every method I've come up with thus far has been almost correct, but each one never quite worked exactly the way I hoped it would. Currently what I do is get two bounding boxes for my entity, one modified by the X translation component and the other by the Z component, and check if each collides with any of the surrounding chunks (chunks have their own octrees that are populated only with blocks that support collision). If there is a collision, then I cast out rays into that chunk to get the shortest collision distance, and set the translation component to that distance if the component is greater than the distance. The problem is that sometimes collisions aren't even registered. Here's a video on YouTube that I created showing what I mean. I suspect the problem may be with the rays that I cast to get the collision distance not being where I think they are, but I'm not entirely sure what would be wrong with them if they are indeed the problem. Here is my code for collision detection and response in the X direction (the Z direction is basically the same): // create the XZ offset vector Vector3 offsXZ = new Vector3( ( _translation.X > 0.0f ) ? SizeX / 2.0f : ( _translation.X < 0.0f ) ? -SizeX / 2.0f : 0.0f, 0.0f, ( _translation.Z > 0.0f ) ? SizeZ / 2.0f : ( _translation.Z < 0.0f ) ? -SizeZ / 2.0f : 0.0f ); // X physics BoundingBox boxx = GetBounds( _translation.X, 0.0f, 0.0f ); if ( _translation.X > 0.0f ) { foreach ( Chunk chunk in surrounding ) { if ( chunk.Collides( boxx ) ) { float dist = GetShortestCollisionDistance( chunk, Vector3.Right, offsXZ ) - 0.0001f; if ( dist < _translation.X ) { _translation.X = dist; } } } } else if ( _translation.X < 0.0f ) { foreach ( Chunk chunk in surrounding ) { if ( chunk.Collides( boxx ) ) { float dist = GetShortestCollisionDistance( chunk, Vector3.Left, offsXZ ) - 0.0001f; if ( dist < -_translation.X ) { _translation.X = -dist; } } } } And here is my implementation for GetShortestCollisionDistance: private float GetShortestCollisionDistance( Chunk chunk, Vector3 rayDir, Vector3 offs ) { int startY = (int)( -SizeY / 2.0f ); int endY = (int)( SizeY / 2.0f ); int incY = (int)Cube.Size; float dist = Chunk.Size; for ( int y = startY; y <= endY; y += incY ) { // Position is the center of the entity's bounding box Ray ray = new Ray( new Vector3( Position.X + offs.X, Position.Y + offs.Y + y, Position.Z + offs.Z ), rayDir ); // Chunk.GetIntersections(Ray) returns Dictionary<Block, float?> foreach ( var pair in chunk.GetIntersections( ray ) ) { if ( pair.Value.HasValue && pair.Value.Value < dist ) { dist = pair.Value.Value; } } } return dist; } I realize some of this code can be consolidated to help with speed, but my main concern right now is to get this bit of physics programming to actually work.

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• Come up with a real-world problem in which only the best solution will do (a problem from Introduction to algorithms) [closed]

  - by Mike

  EDITED (I realized that the question certainly needs a context) The problem 1.1-5 in the book of Thomas Cormen et al Introduction to algorithms is: "Come up with a real-world problem in which only the best solution will do. Then come up with one in which a solution that is “approximately” the best is good enough." I'm interested in its first statement. And (from my understanding) it is asked to name a real-world problem where only the exact solution will work as opposed to a real-world problem where good-enough solution will be ok. So what is the difference between the exact and good enough solution. Consider some physics problem for example the simulation of the fulid flow in the permeable medium. To make this simulation happen some simplyfing assumptions have to be made when deriving a mathematical model. Otherwise the model becomes at least complex and unsolvable. Virtually any particle in the universe has its influence on the fluid flow. But not all particles are equal. Those that form the permeable medium are much more influental than the ones located light years away. Then when the mathematical model needs to be solved an exact solution can rarely be found unless the mathematical model is simple enough (wich probably means the model isn't close to reality). We take an approximate numerical method and after hours of coding and days of verification come up with the program or algorithm which is a solution. And if the model and an algorithm give results close to a real problem by some degree that is good enough soultion. Its worth noting the difference between exact solution algorithm and exact computation result. When considering real-world problems and real-world computation machines I believe all physical problems solutions where any calculations are taken can not be exact because universal physical constants are represented approximately in the computer. Any numbers are represented with the limited precision, at least limited by amount of memory available to computing machine. I can imagine plenty of problems where good-enough, good to some degree solution will work, like train scheduling, automated trading, satellite orbit calculation, health care expert systems. In that cases exact solutions can't be derived due to constraints on computation time, limitations in computer memory or due to the nature of problems. I googled this question and like what this guy suggests: there're kinds of mathematical problems that need exact solutions (little note here: because the question is taken from the book "Introduction to algorithms" the term "solution" means an algorithm or a program, which in this case gives exact answer on each input). But that's probably more of theoretical interest. So I would like to narrow down the question to: What are the real-world practical problems where only the best (exact) solution algorithm or program will do (but not the good-enough solution)? There are problems like breaking of cryptographic ciphers where only exact solution matters in practice and again in practice the process of deciphering without knowing a secret should take reasonable amount of time. Returning to the original question this is the problem where good-enough (fast-enough) solution will do there's no practical need in instant crack though it's desired. So the quality of "best" can be understood in any sense: exact, fastest, requiring least memory, having minimal possible network traffic etc. And still I want this question to be theoretical if possible. In a sense that there may be example of computer X that has limited resource R of amount Y where the best solution to problem P is the one that takes not more than available Y for inputs of size N*Y. But that's the problem of finding solution for P on computer X which is... well, good enough. My final thought that we live in a world where it is required from programming solutions to practical purposes to be good enough. In rare cases really very very good but still not the best ones. Isn't it? :) If it's not can you provide an example? Or can you name any such unsolved problem of practical interest?

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• Why is the framerate (fps) capped at 60?

  - by dennmat

  ISSUE I recently moved a project from my laptop to my desktop(machine info below). On my laptop the exact same code displays the fps(and ms/f) correctly. On my desktop it does not. What I mean by this is on the laptop it will display 300 fps(for example) where on my desktop it will show only up to 60. If I add 100 objects to the game on the laptop I'll see my frame rate drop accordingly; the same test on the desktop results in no change and the frames stay at 60. It takes a lot(~300) entities before I'll see a frame drop on the desktop, then it will descend. It seems as though its "theoretical" frames would be 400 or 500 but will never actually get to that and only do 60 until there's too much to handle at 60. This 60 frame cap is coming from no where. I'm not doing any frame limiting myself. It seems like something external is limiting my loop iterations on the desktop, but for the last couple days I've been scratching my head trying to figure out how to debug this. SETUPS Desktop: Visual Studio Express 2012 Windows 7 Ultimate 64-bit Laptop: Visual Studio Express 2010 Windows 7 Ultimate 64-bit The libraries(allegro, box2d) are the same versions on both setups. CODE Main Loop: while(!abort) { frameTime = al_get_time(); if (frameTime - lastTime >= 1.0) { lastFps = fps/(frameTime - lastTime); lastTime = frameTime; avgMspf = cumMspf/fps; cumMspf = 0.0; fps = 0; } /** DRAWING/UPDATE CODE **/ fps++; cumMspf += al_get_time() - frameTime; } Note: There is no blocking code in the loop at any point. Where I'm at My understanding of al_get_time() is that it can return different resolutions depending on the system. However the resolution is never worse than seconds, and the double is represented as [seconds].[finer-resolution] and seeing as I'm only checking for a whole second al_get_time() shouldn't be responsible. My project settings and compiler options are the same. And I promise its the same code on both machines. My googling really didn't help me much, and although technically it's not that big of a deal. I'd really like to figure this out or perhaps have it explained, whichever comes first. Even just an idea of how to go about figuring out possible causes, because I'm out of ideas. Any help at all is greatly appreciated. EDIT: Thanks All. For any others that find this to disable vSync(windows only) in opengl: First get "wglext.h". It's all over the web. Then you can use a tool like GLee or just write your own quick extensions manager like: bool WGLExtensionSupported(const char *extension_name) { PFNWGLGETEXTENSIONSSTRINGEXTPROC _wglGetExtensionsStringEXT = NULL; _wglGetExtensionsStringEXT = (PFNWGLGETEXTENSIONSSTRINGEXTPROC) wglGetProcAddress("wglGetExtensionsStringEXT"); if (strstr(_wglGetExtensionsStringEXT(), extension_name) == NULL) { return false; } return true; } and then create and setup your function pointers: PFNWGLSWAPINTERVALEXTPROC wglSwapIntervalEXT = NULL; PFNWGLGETSWAPINTERVALEXTPROC wglGetSwapIntervalEXT = NULL; if (WGLExtensionSupported("WGL_EXT_swap_control")) { // Extension is supported, init pointers. wglSwapIntervalEXT = (PFNWGLSWAPINTERVALEXTPROC) wglGetProcAddress("wglSwapIntervalEXT"); // this is another function from WGL_EXT_swap_control extension wglGetSwapIntervalEXT = (PFNWGLGETSWAPINTERVALEXTPROC) wglGetProcAddress("wglGetSwapIntervalEXT"); } Then just call wglSwapIntervalEXT(0) to disable vSync and 1 to enable vSync. I found the reason this is windows only is that openGl actually doesn't deal with anything other than rendering it leaves the rest up to the OS and Hardware. Thanks everyone saved me a lot of time!

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• How to parse a CSV file containing serialized PHP? [migrated]

  - by garbetjie

  I've just started dabbling in Perl, to try and gain some exposure to different programming languages - so forgive me if some of the following code is horrendous. I needed a quick and dirty CSV parser that could receive a CSV file, and split it into file batches containing "X" number of CSV lines (taking into account that entries could contain embedded newlines). I came up with a working solution, and it was going along just fine. However, as one of the CSV files that I'm trying to split, I came across one that contains serialized PHP code. This seems to break the CSV parsing. As soon as I remove the serialization - the CSV file is parsed correctly. Are there any tricks I need to know when it comes to parsing serialized data in CSV files? Here is a shortened sample of the code: use strict; use warnings; my $csv = Text::CSV_XS->new({ eol => $/, always_quote => 1, binary => 1 }); my $out; my $in; open $in, "<:encoding(utf8)", "infile.csv" or die("cannot open input file $inputfile"); open $out, ">outfile.000"; binmode($out, ":utf8"); while (my $line = $csv->getline($in)) { $lines++; $csv->print($out, $line); } I'm never able to get into the while loop shown above. As soon as I remove the serialized data, I suddenly am able to get into the loop. Edit: An example of a line that is causing me trouble (taken straight from Vim - hence the ^M): "26","other","1","20,000 Subscriber Plan","Some text here.^M\ Some more text","on","","18","","0","","0","0","recurring","0","","payment","totalsend","0","tsadmin","R34bL9oq","37","0","0","","","","","","","","","","","","","","","","","","","","","","","0","0","0","a:18:{i:0;s:1:\"3\";i:1;s:1:\"2\";i:2;s:2:\"59\";i:3;s:2:\"60\";i:4;s:2:\"61\";i:5;s:2:\"62\";i:6;s:2:\"63\";i:7;s:2:\"64\";i:8;s:2:\"65\";i:9;s:2:\"66\";i:10;s:2:\"67\";i:11;s:2:\"68\";i:12;s:2:\"69\";i:13;s:2:\"70\";i:14;s:2:\"71\";i:15;s:2:\"72\";i:16;s:2:\"73\";i:17;s:2:\"74\";}","","","0","0","","0","0","0.0000","0.0000","0","","","0.00","","6","1" "27","other","1","35,000 Subscriber Plan","Some test here.^M\ Some more text","on","","18","","0","","0","0","recurring","0","","payment","totalsend","0","tsadmin","R34bL9oq","38","0","0","","","","","","","","","","","","","","","","","","","","","","","0","0","0","a:18:{i:0;s:1:\"3\";i:1;s:1:\"2\";i:2;s:2:\"59\";i:3;s:2:\"60\";i:4;s:2:\"61\";i:5;s:2:\"62\";i:6;s:2:\"63\";i:7;s:2:\"64\";i:8;s:2:\"65\";i:9;s:2:\"66\";i:10;s:2:\"67\";i:11;s:2:\"68\";i:12;s:2:\"69\";i:13;s:2:\"70\";i:14;s:2:\"71\";i:15;s:2:\"72\";i:16;s:2:\"73\";i:17;s:2:\"74\";}","","","0","0","","0","0","0.0000","0.0000","0","","","0.00","","7","1" "28","other","1","50,000 Subscriber Plan","Some text here.^M\ Some more text","on","","18","","0","","0","0","recurring","0","","payment","totalsend","0","tsadmin","R34bL9oq","39","0","0","","","","","","","","","","","","","","","","","","","","","","","0","0","0","a:18:{i:0;s:1:\"3\";i:1;s:1:\"2\";i:2;s:2:\"59\";i:3;s:2:\"60\";i:4;s:2:\"61\";i:5;s:2:\"62\";i:6;s:2:\"63\";i:7;s:2:\"64\";i:8;s:2:\"65\";i:9;s:2:\"66\";i:10;s:2:\"67\";i:11;s:2:\"68\";i:12;s:2:\"69\";i:13;s:2:\"70\";i:14;s:2:\"71\";i:15;s:2:\"72\";i:16;s:2:\"73\";i:17;s:2:\"74\";}","","","0","0","","0","0","0.0000","0.0000","0","","","0.00","","8","1""73","other","8","10,000,000","","","","0","","0","","0","0","recurring","0","","payment","","0","","","75","0","10000000","","","","","","","","","","","","","","","","","","","","","","","0","0","0","a:17:{i:0;s:1:\"3\";i:1;s:1:\"2\";i:2;s:2:\"59\";i:3;s:2:\"60\";i:4;s:2:\"61\";i:5;s:2:\"62\";i:6;s:2:\"63\";i:7;s:2:\"64\";i:8;s:2:\"65\";i:9;s:2:\"66\";i:10;s:2:\"67\";i:11;s:2:\"68\";i:12;s:2:\"69\";i:13;s:2:\"70\";i:14;s:2:\"71\";i:15;s:2:\"72\";i:16;s:2:\"74\";}","","","0","0","","0","0","0.0000","0.0000","0","","","0.00","","14","0"

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• Building Enterprise Smartphone App &ndash; Part 1: Why Build Smart Phone Apps

  - by Tim Murphy

  This is part 1 in a series of post based on a talk I gave recently at the Chicago Information Technology Architects Group.  Feel free to leave feedback. Intro Most of us already carry smartphones. We play games on them. We keep up with what is going on with our friends and our favorite teams. We take pictures of our kids at their events. But the question is if that is all they are good for. Many companies have aspects of their business that lend themselves to being performed by mobile devices. Some of them lean toward larger device such as tablets, but many can be executed on smartphones. This and the following articles will discuss some of the possible applications of smartphone technology for businesses, the platforms that are available and the considerations you need to make when building them. I'll take a look at some specific scenarios and wrap up with a couple of capabilities that are just emerging that can be used in the future. Why Build Enterprise Smartphone Applications So what are some of the ways that you can leverage smartphone technology to gain efficiency in your business or a clients business. There are a few major areas that I have seen mobile platforms being an advantage to. Your mobile sales force is a key candidate for leveraging smartphone apps.  They can visit clients in their retail location and place orders on site. It is a more personal approach which can gain you customer loyalty.  A sales person may also gather information about the way a client does business or who their target market is. This allows them you to focus marketing information or build customized support for your customer. You may also have need to track physical inventory in a store. This is something that has historically been done with laser scanners, but with the camera capabilities in today's phones and tablets it is possible to use more general multi-purpose devices.  This can save costs on both hardware and telecommunication contracts. Delivery verification is another area that historically has been the domain of specialized devices but can now be accomplished with smartphones.  This also reduces costs because it is also used for communicating with the driver and other operations.  Add to that the navigation capability of smartphones and you can see how the return on investment increases. Executives are always on the go. They spend most of their time in meetings and yet they need access to decision making information at their finger tips. With a smartphone app they can get alerts when major sales are closed or critical accounting process are completed that may need their attention. They can also answer questions by instantly pulling up BI reports. I have often heard operations support people say that they need things like VPN and RDP from their phones. If they can also have notifications of outages or critical support requests they can be react to situations without needing to be tied to their desks. These are all valid reasons to need smartphone applications.  In the next installment I will discuss platforms and features. del.icio.us Tags: Smartphones,Enterprise Smartphone Apps,Architecture

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• Rethinking Oracle Optimizer Statistics for P6 Part 2

  - by Brian Diehl

  In the previous post (Part 1), I tried to draw some key insights about the relationship between P6 and Oracle Optimizer Statistics.  The first is that average cardinality has the greatest impact on query optimization and that the particular queries generated by P6 are more likely to use this average during calculations. The second is that these are statistics that are unlikely to change greatly over the life of the application. Ultimately, our goal is to get the best query optimization possible.  Or is it? Stability No application administrator wants to get the call at 9am that their application users cannot get there work done because everything is running slow. This is a possibility with a regularly scheduled nightly collection of statistics. It may not just be slow performance, but a complete loss of service because one or more queries are optimized poorly. Ideally, this should not be the case. The database optimizer should make better decisions with more up-to-date data. Better statistics may give incremental performance benefit. However, this benefit must be balanced against the potential cost of system down time.  It is stability that we ultimately desire and not absolute optimal performance. We do want the benefit from more accurate statistics and better query plans, but not at the risk of an unusable system. As a result, I've developed the following methodology around managing database statistics for the P6 database.  1. No Automatic Re-Gathering - The daily, weekly, or other interval of statistic gathering is unlikely to be beneficial. Quite the opposite. It is more likely to cause problems. 2. Smart Re-Gathering - The time to collect statistics is when things have changed significantly. For a new installation of P6, this is happening more often because the data is growing from a few rows to thousands and more. But for a mature system, the data is not changing significantly from week-to-week. There are times to collect statistics: New releases of the application Changes in the underlying hardware or software versions (ex. new Oracle RDBMS version) When additional user groups are added. The new groups may use the software in significantly different ways. After significant changes in the data. This may be monthly, quarterly or yearly.  3. Always Test - If you take away one thing from this post, it would be to always have a plan to test after changing statistics. In reality, statistics can be collected as often as you desire provided there are tests in place to verify that performance is the same or better. These might be automated tests or simply a manual script of application functions. 4. Have a Way Out - Never change the statistics without a way to return to the previous set. Think of the statistics as one part of the overall application code that also includes the source code--both application and RDBMS. It would be foolish to change to the new code without a way to get back to the previous version. In the final post, I will talk about the actual script I created for P6 PMDB and possible future direction for managing query performance. 

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• Making user input/math on data fast, unlike excel type programs

  - by proGrammar

  I'm creating a research platform solely for myself to do some research on data. Programs like excel are terribly slow for me so I'm trying to come up with another solution. Originally I used excel. A1 was the cell that contained the data and all other cells in use calculated something on A1, or on other cells, that all could be in the end traced to A1. A1 was like an element of an array, I then I incremented it to go through all my data. This was way too slow. So the only other option I found originally was to hand code in c# the calculations inside a loop. Then I simply recompiled each time I changed my math. This was terribly slow to do and I had to order everything correctly so things would update correctly (dependencies). I could have also used events, but hand coding events for each cell like calculation would also be very slow. Next I created an application to read Excel and to perfectly imitate it. Which is what I now use. Basically I write formulas onto a fraction of my data to get live results inside excel. Then my program reads excel, writes another c# program, compiles it, and runs that program which runs my excel created formulas through a lot more data a whole lot faster. The advantage being my application dependency sorts everything (or I could use events) so I don't have to (like excel does) And of course the speed. But now its not a single application anymore. Instead its 2 applications, one which only reads my formulas and writes another program. The other one being the result which only lives for a short while before I do other runs through my data with different formulas / settings. So I can't see multiple results at one time without introducing even more programs like a database or at least having the 2 applications talking to each other. My idea was to have a dll that would be written, compiled, loaded, and unloaded again and again. So a self-updating program, sort of. But apparently that's not possible without another appdomain which means data has to be marshaled to be moved between the appdomains. Which would slow things down, not for summaries, but for other stuff I need to do with all my data. I'm also forgetting to mention a huge problem with restarting an application again and again which is having to reload ALL my data into memory again and again. But its still a whole lot faster than excel. I'm really super puzzled as to what people do when they want to research data fast. I'm completely unable to have a program accept user input and having it fast. My understanding is that it would have to do things like excel which is to evaluate strings again and again. So my only option is to repeatedly compile applications. Do I have a correct understanding on computer science? I've only just began programming, and didn't think I would have to learn much to do some simple math on data. My understanding is its either compiling my user defined stuff to a program or evaluating them from a string or something stupid again and again. And my only option is to probably switch operating systems or something to be able to have a program compile and run itself without stopping (writing/compiling dll, loading dll to program, unloading, and repeating). Can someone give me some idea on how computers work? Is anything better possible? Like a running program, that can accept user input and compile it and then unload it later? I mean heck operating systems dont need to be RESTARTED with every change to user input. What is this the cave man days? Sorry, it's just so super frustrating not knowing what one can do, and can't do. If only I could understand and learn this stuff fast enough.

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• I need help with 2D collision response (of stacking rotating polygons, with friction and gravity, for a game)

  - by Register Sole

  Hi I am looking for suggestions on how to write a collision response for game programming purpose (so not a scientific simulation). I am dealing with 2D polygons that are rotating, and I want them to be able to stack. I also want friction and gravity. I have a detection mechanism that returns the separating axis, how long the polygons are overlapping, and up to 2 points of contact. For the response, I am currently using an impulse-based response, which main idea is: find the separating axis, length of overlap, and the point of contact (if there are two, pick a random point between to simulate averaged force. i believe there are better ways than this) separate the object (modifying their positions, taking into account of their masses. i do not separate them completely though, to keep track that they are colliding to reduce jitter) calculate normal force based on the coefficient of restitution as if there is no friction. calculate friction, as if there is no normal force. I also assume that the direction of the friction is the same throughout the collision. apply the two forces (which result in a rather inaccurate result, since each force is calculated as if the other is not present. for non-rotating bodies though, this method is exact) I am aware that this method requires the coefficient of friction to be sufficiently small due to the assumption that the direction of friction stays the same in a collision. Also, the result is visually satisfying if gravity is not present. However, when there is gravity, objects on ground jitter and drift (even with zero coefficient of restitution)! It also happens for stacking objects. Larger coefficient of restitution and gravity increase the jittering. I hope you can help me with this. Some things i would like to know more about is how to handle collision with two point of contacts (how to end up having an object sitting still on the ground?), how to reduce, and prevent if possible, jitter and drift (do people use the most accurate method possible, or is there a trick to overcome this?), and how to handle multiple objects collision (for example, in the case of stacking objects, how do I check collisions between all of them and keep them all stable at every frame so they don't jitter?). A total reformulation of my algorithm is also welcomed, as long as it works. Another thing to note is that I am not making a Physics game, so I only need a visually satisfying response (though a realistic response is preferable, if it is not performance-heavy). But surely jittering and drifting objects on flat ground are not at all acceptable. In addition, I am a Physics student, so feel free to talk about impulse and whatever needed. Finally, I'm sorry for the long post. I tried to be as concise as I can. Thank you for reading it! EDIT It seems what I didn't manage to come up all this time is to separate resting contact as a class of its own and how to solve them. Currently reading the paper suggested by Jedediah. More suggestions on the topic are welcome :) CASE CLOSED After reading various papers referenced in the paper, successfully implemented simultaneous impulse method (referring to the original paper by Erin Catto, [Catt05]). Thanks maaaan!! The paper is wonderful. The current system is visibly much better than the previous. Still haven't separated resting contact as a class of its own though, which brings me to my next question. Love you all! Haha (sorry, I'm just so happy thanks to you).

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• 11???OTN?????????????&???? (10/24 ??)

  - by OTN-J Master

  ???????????????????????????????????????????????????????????????????????????? ???11????????????????????????????????????????????????????????????????????????????????????????????11?????????????????????????????????????????Oracle DBA & Developer Day??14?????????????????????????????????????????????????????????????????????????????????????????????????????????!10??????????? ?10/24???????? Oracle Database Appliance??? 11?6?(?)15:30 ~ 17:00 @ ??????????(??????)??????????????????????????????????·?????Oracle Database Appliance????????????????????????????????????????????????Oracle Database Appliance?????·???????????????·??????????????????????????Oracle Database Appliance????????????????? ?????!?????????????????? 11?7?(?)13:30 ~ 17:10 @  ??????????(??????)????????Oracle Database 11g Release2??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????·????????????????????????????? ???Java?3?????!Java?????? 11?12?(?)14:30 ~ 17:30 @  ??????????(??????)????????????????????????????????????·?????????????Java???????????????????Java???????????????????????????????????????????????????????????????????????? ?????????????????Java?????????????????????????????????????Java????????????????????????????? JPOUG Tech Talk Night #3 “Upgrade, Migrate and Consolidate to Oracle Database 12c(?)” 11?12?(?)19:00 ~20:30 @ ??????????(??·???) ???????? JPOUG??????????????????????????US?Oracle ????? 2?????Oracle Database 12c??????????????????????? ???????Oracle OpenWorld?????????????????????? ???????????Web??????????????????????? ??????????????????????????????????! ????! ???????? ~WebLogic Server???????????~ ]?1?] ???????????????11?13?(?)18:30 ~20:00 @ ?????? ????????????(??)?WebLogic Server ??????????????????Java???????????????Java EE??????WebLogic Server?JVM???????????????????????????????????????????????WebLogic Server???????????????????WebLogic Server?????????????????????????????????????11g(10.3.6)????12c(12.1.2)??????????????????????????????? ??????WebLogic Server???????????!Oracle DBA & Developer Day 2013 11?14?(?) @ ???????????(??·???)Oracle Database?Oracle WebLogic Server?Oracle Coherence?Oracle Solaris??????????????????????????????????????1?????????????????????????? ??????????????????????·????????????????????????????????6???????????????· Oracle Database - ???????·???????????????·????· Oracle Database - ??????·??????????· Oracle Database - ??????????· Oracle Database 12c?????? (Oracle University??)· Oracle Fusion Middleware????????· Oracle Solaris?Oracle Hardware????????? ">????!????????????????????????11?19?(?)14:30 ~ 16:50 @ ??????????(??????)??????????????????????????????????????????????????????????????????????????????????????????????????????? ???? ??????????????????????????????????????????????????????????????????????????????????????????????????????????E??????????????????????????????????????????????????????????? ????~!!?????????????????!~????????????~?presented by ???? 11?20?(?)18:30~20:00 @ ?????????? ???? ???????(??)????·??????????????????????????????????????????????????????????????!???????????????Oracle??????????????????????????????????Oracle Database ?????????????????????????????????????????Database Configuration Assitant??????????????????????????????????????????????? ??Oracle Database????????????????????????????????????????Database??(??·???·??????)???????????????????????!?????! ?????????/???????????? 11?21?(?)10:00 ~ 17:30 @ ??????????(??????)?Oracle Application Testing Suite??Web?????????????????????????????????????????????????????????????????????????????????????????????????????????????????Oracle Application Testing Suite?????????????????????????????????????????????????????Oracle Exadata ???? ???? 11?21?(?)13:30 ~ 17:30 @ ??????????(??????)11?28?(?)13:30 ~ 17:30 @ ?????? ????????????(??)?????????????????Oracle Exadata X3 Database In-Memory Machine???·????????????????????????????????????????????????????????????????????Oracle Exadata????????????????????????????????????????????????????????????????? ?! Click??????? in ?? ~90?????! Oracle Database 12c??? & Oracle Database ??????? ~11?22?(?)13:30~16:50 @  ???????? 406???????Oracle Database ??????????????????????????·????????????????????????????? Oracle Database12c ?????90?????????! ???????????? ~Oracle Database 12c ??? ??? ~11?27?(?)18:30 ~20:00 @ ?????????????????(???)Oracle ???????SQL????????????????????????????????????SQL?????????????????????Oracle Database 12c?????????????????????????????????????????????????????????Oracle Database 12c???????????????11g?????????????? ???????????35???? ~??????·??????&Oracle Database?????? ~11?29?(?)13:30 ~16:40 @ RCC?????? 7F 704???(??)?35?????????????????? Oracle?????????????·?????? ?Enterprise Manager???????????????Tips ?????????????????!?????????????????!!

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