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• Get Started with JavaFX 2 and Scene Builder

  - by Janice J. Heiss

  Up on otn/java is a very useful article by Oracle Java/Middleware/Core Tech Engineer Mark Heckler, titled, “How to Get Started (FAST!) with JavaFX 2 and Scene Builder.”  Heckler, who has development experience in numerous environments, shows developers how to develop a JavaFX application using Scene Builder “in less time than it takes to drink a cup of coffee, while learning your way around in the process”. He begins with a warning and a reassurance: “JavaFX is a new paradigm and can seem a bit imposing when you first take a look at it. But remember, JavaFX is easy and fun. Let's give it a try.” Next, after showing readers how to download and install JDK/JavaFX and Scene Builder, he informs the reader that they will “create a simple JavaFX application, create and modify a window using Scene Builder, and successfully test it in under 15 minutes.” Then readers download some NetBeans files:“EasyJavaFX.java contains the main application class. We won't do anything with this class for our example, as its primary purpose in life is to load the window definition code contained in the FXML file and then show the main stage/scene. You'll keep the JavaFX terms straight with ease if you relate them to the theater: a platform holds a stage, which contains scenes. SampleController.java is our controller class that provides the ‘brains’ behind the graphical interface. If you open the SampleController, you'll see that it includes a property and a method tagged with @FXML. This tag enables the integration of the visual controls and elements you define using Scene Builder, which are stored in an FXML (FX Markup Language) file. Sample.fxml is the definition file for our sample window. You can right-click and Edit the filename in the tree to view the underlying FXML -- and you may need to do that if you change filenames or properties by hand - or you can double-click on it to open it (visually) in Scene Builder.” Then Scene Builder enters the picture and the task is soon done. Check out the article here.

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• Got that Friday feeling?

  - by Rebecca Amos

  Saturday is just around the corner, and we’re all starting to wrap up for the weekend. If you’re the DBA that ‘Friday feeling’ might be as much about checking and preparing your SQL Servers for the next two days, as about looking forward to spending time with friends and family. Whether you’re double-checking your disaster recovery strategy, or know that it’s your turn to be on-call this weekend, it’s likely you’re preparing for the worst, just in case. The fact that you’re making these checks, and caring about both your servers and your users, means that you might be an exceptional DBA. You’re already putting in that extra effort to make other people’s lives easier. So why not take some time for your professional development and enter the Exceptional DBA Awards? If you’re looking for some inspiration for your entry, download our Judges’ Top Tips poster for advice on what the judges are looking for from this year’s entrants. Not only will you be boosting your professional development, but you could win full conference registration for the 2011 PASS Summit in Seattle (where the awards ceremony will take place), four nights' hotel accommodation, and a copy of Red Gate’s SQL DBA Bundle. So take some time out for yourself this weekend and get started on your entry: www.exceptionaldba.com

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• Give a session on C++ AMP – here is how

  - by Daniel Moth

  Ever since presenting on C++ AMP at the AMD Fusion conference in June, then the Gamefest conference in August, and the BUILD conference in September, I've had numerous requests about my material from folks that want to re-deliver the same session. The C++ AMP session I put together has evolved over the 3 presentations to its final form that I used at BUILD, so that is the one I recommend you base yours on. Please get the slides and the recording from channel9 (I'll refer to slide numbers below). This is how I've been presenting the C++ AMP session: Context (slide 3, 04:18-08:18) Start with a demo, on my dual-GPU machine. I've been using the N-Body sample (for VS 11 Developer Preview). (slide 4) Use an nvidia slide that has additional examples of performance improvements that customers enjoy with heterogeneous computing. (slide 5) Talk a bit about the differences today between CPU and GPU hardware, leading to the fact that these will continue to co-exist and that GPUs are great for data parallel algorithms, but not much else today. One is a jack of all trades and the other is a number cruncher. (slide 6) Use the APU example from amd, as one indication that the hardware space is still in motion, emphasizing that the C++ AMP solution is a data parallel API, not a GPU API. It has a future proof design for hardware we have yet to see. (slide 7) Provide more meta-data, as blogged about when I first introduced C++ AMP. Code (slide 9-11) Introduce C++ AMP coding with a simplistic array-addition algorithm – the slides speak for themselves. (slide 12-13) index<N>, extent<N>, and grid<N>. (Slide 14-16) array<T,N>, array_view<T,N> and comparison between them. (Slide 17) parallel_for_each. (slide 18, 21) restrict. (slide 19-20) actual restrictions of restrict(direct3d) – the slides speak for themselves. (slide 22) bring it altogether with a matrix multiplication example. (slide 23-24) accelerator, and accelerator_view. (slide 26-29) Introduce tiling incl. tiled matrix multiplication [tiling probably deserves a whole session instead of 6 minutes!]. IDE (slide 34,37) Briefly touch on the concurrency visualizer. It supports GPU profiling, but enhancements specific to C++ AMP we hope will come at the Beta timeframe, which is when I'll be spending more time talking about it. (slide 35-36, 51:54-59:16) Demonstrate the GPU debugging experience in VS 11. Summary (slide 39) Re-iterate some of the points of slide 7, and add the point that the C++ AMP spec will be open for other compiler vendors to implement, even on other platforms (in fact, Microsoft is actively working on that). (slide 40) Links to content – see slide – including where all your questions should go: http://social.msdn.microsoft.com/Forums/en/parallelcppnative/threads.   "But I don't have time for a full blown session, I only need 2 (or just 1, or 3) C++ AMP slides to use in my session on related topic X" If all you want is a small number of slides, you can take some from the session above and customize them. But because I am so nice, I have created some slides for you, including talking points in the notes section. Download them here. Comments about this post by Daniel Moth welcome at the original blog.

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• How to Transfer All Your Information to a New PS3

  - by Justin Garrison

  The PlayStation 3 now costs half the price, has double the storage, and uses half the power. If you need another reason to upgrade, Sony also makes it easy to transfer all of your information to a new console. Transferring all of your games, data, and settings is easier than ever, and all you need is an ethernet cable. Read on as we walk you through the whole process of setting up your new PS3 and wiping all your information off the old one. Latest Features How-To Geek ETC Learn To Adjust Contrast Like a Pro in Photoshop, GIMP, and Paint.NET Have You Ever Wondered How Your Operating System Got Its Name? Should You Delete Windows 7 Service Pack Backup Files to Save Space? What Can Super Mario Teach Us About Graphics Technology? Windows 7 Service Pack 1 is Released: But Should You Install It? How To Make Hundreds of Complex Photo Edits in Seconds With Photoshop Actions Hack Apart a Highlighter to Create UV-Reactive Flowers [Science] Add a “Textmate Style” Lightweight Text Editor with Dropbox Syncing to Chrome and Iron Is the Forcefield Really On or Not? [Star Wars Parody Video] Google Updates Picasa Web Albums; Emphasis on Sharing and Showcasing Uwall.tv Turns YouTube into a Video Jukebox Early Morning Sunrise at the Beach Wallpaper

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• Is there an excuse for short variable names?

  - by KChaloux

  This has become a large frustration with the codebase I'm currently working in; many of our variable names are short and undescriptive. I'm the only developer left on the project, and there isn't documentation as to what most of them do, so I have to spend extra time tracking down what they represent. For example, I was reading over some code that updates the definition of an optical surface. The variables set at the start were as follows: double dR, dCV, dK, dDin, dDout, dRin, dRout dR = Convert.ToDouble(_tblAsphere.Rows[0].ItemArray.GetValue(1)); dCV = convert.ToDouble(_tblAsphere.Rows[1].ItemArray.GetValue(1)); ... and so on Maybe it's just me, but it told me essentially nothing about what they represented, which made understanding the code further down difficult. All I knew was that it was a variable parsed out specific row from a specific table, somewhere. After some searching, I found out what they meant: dR = radius dCV = curvature dK = conic constant dDin = inner aperture dDout = outer aperture dRin = inner radius dRout = outer radius I renamed them to essentially what I have up there. It lengthens some lines, but I feel like that's a fair trade off. This kind of naming scheme is used throughout a lot of the code however. I'm not sure if it's an artifact from developers who learned by working with older systems, or if there's a deeper reason behind it. Is there a good reason to name variables this way, or am I justified in updating them to more descriptive names as I come across them?

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• Synaptics drivers are not loading on Kubuntu 13.10 on Dell Vostro 2420

  - by Alok Singh Mahor

  I freshly installed Kubuntu 13.10, 32 bit version on newly purchased Dell Vostro 2420. everything is working fine except scrolling and multitouch features through touchpad. I am able to change position of cursor using touchpad and able to tap (single click and double click) but scrolling is not working I tried to find out solution by searching on google but could not find proper solution to load synaptics drivers. i am listing some details: Laptop: Dell Vostro 2420 Linux Kernel version and distribution: 3.11.0-12-generic, Kubuntu 13.10 output of xinput list is ? Virtual core pointer id=2 [master pointer (3)] ? ? Virtual core XTEST pointer id=4 [slave pointer (2)] ? ? PS/2 Generic Mouse id=12 [slave pointer (2)] ? Virtual core keyboard id=3 [master keyboard (2)] ? Virtual core XTEST keyboard id=5 [slave keyboard (3)] ? Power Button id=6 [slave keyboard (3)] ? Video Bus id=7 [slave keyboard (3)] ? Power Button id=8 [slave keyboard (3)] ? Sleep Button id=9 [slave keyboard (3)] ? Laptop_Integrated_Webcam_HD id=10 [slave keyboard (3)] ? AT Translated Set 2 keyboard id=11 [slave keyboard (3)] ? Dell WMI hotkeys id=13 [slave keyboard (3)] Output of synclient -l is Couldn't find synaptics properties. No synaptics driver loaded? output of lshw is at http://paste.ubuntu.com/6645687/ xserver log and dmesg dont have trace of synaptics kindly tell me how to troubleshoot this problem.

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• Issues glVertexAttribPointer last 2 parameters?

  - by NoobScratcher

  Introduction Hello I will start out by explaining my setup, showing samples as I go along explaining the situation. I'm using these tools: OpenGL 3.3 GLSL 330 C++ Problem The problem is when I render the wavefront obj 3d model it gives a very weird visual glitch the model was supposed to be a square but instead its a triangluated mess with parts of the vertexes pointing in a stretched direction in massive amounts towards the bottom left side of the frustum.... Explanation: I'm using std::vectors to store my wavefront .obj model data using sscanf to get the floating point values into the structure members x,y,z and store them into the Points structure variable p; int index = IndexAssigner(1, 1); ifstream file (list[index].c_str() ); points.push_back(Point()); Point p; int face[4]; while (!file.eof() ) { char modelbuffer[10000]; file.getline(modelbuffer, 10000); switch(modelbuffer[0]) { case 'v' : sscanf(modelbuffer, "v %f %f %f", &p.x, &p.y, &p.z); points.push_back(p); break; case 'f': sscanf(modelbuffer, "f %d %d %d %d", face, face+1, face+2, face+3 ); faces.push_back(face[0]); faces.push_back(face[1]); faces.push_back(face[2]); faces.push_back(face[3]); } //Turn on FileReader aka "RENDER CODE" FileReader = true; } then I render the Points vector using the .data() member of std::vectors to the frustum. Other declarations: int numfloats = 4; float* point=reinterpret_cast<float*>(&points[0]); int num_bytes=numfloats*sizeof(float); Vector declarations: struct Point {float x, y , z; }; std::vector<int>faces; std::vector<Point>points; Render code: glGenBuffers(1, &vertexbuffer); glGenTextures(1, &ModelTexture); glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer); glBindTexture(GL_TEXTURE_3D, ModelTexture); glTexImage2D(GL_TEXTURE_2D, 0,GL_RGBA, ModelSurface->w, ModelSurface->h, 0, GL_BGR, GL_UNSIGNED_BYTE, ModelSurface->pixels); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); glBufferData(GL_ARRAY_BUFFER, sizeof(points), points.data(), GL_STATIC_DRAW); glVertexAttribPointer(3, 3, GL_FLOAT, GL_FALSE,num_bytes ,points.data()); glEnableVertexAttribArray(3); //Translation Process GLfloat TranslationMatrix[] = { 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 1.0, 0.0, 0.0, 0.0, 1.0 }; //Send Translation Matrix up to the vertex shader glUniformMatrix4fv(translation, 1, TRUE, TranslationMatrix); glDrawElements( GL_QUADS, faces.size(), GL_UNSIGNED_INT, faces.data()); I tried looking at what was causing this and went through every function every parameter ,etc looked at the man pages. Then found out that it could be my glVertexAttribPointer. Here are the man pages for glVertexAttribPointer http://www.opengl.org/sdk/docs/man/xhtml/glVertexAttribPointer.xml The last 2 parameters is my problem How do I write those 2 last parameters do I try putting the data from Points into it?. glVertexAttribPointer(3, 3, GL_FLOAT, GL_FALSE,num_bytes ,points.data()); How does it work with vectors? Is it fast?* if you can not be bothered too look at the man pages here is the scripts coming from the man pages directly. Stride Specifies the byte offset between consecutive generic vertex attributes. If stride is 0, the generic vertex attributes are understood to be tightly packed in the array. The initial value is 0. Pointer Specifies a pointer to the first component of the first generic vertex attribute in the array. The initial value is 0. If you want my full source - http://ideone.com/fPfkg Thanks Again if you do read this.

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• FBX Importer - Texture Name

  - by CmasterG

  I have a problem with the FBX SDK. I read in the data for the vertex position and the uv coordinates. It works fine, but now I want to read for each polygon to which texture it belongs, so that I can have models with multiple textures. Can anyone tell me how I can get the texture name (file name) for my polygon. My code to read in vertex position and uv coordinates is the following: int i, j, lPolygonCount = pMesh->GetPolygonCount(); FbxVector4* lControlPoints = pMesh->GetControlPoints(); int vertexId = 0; for (i = 0; i < lPolygonCount; i++) { int lPolygonSize = pMesh->GetPolygonSize(i); for (j = 0; j < lPolygonSize; j++) { int lControlPointIndex = pMesh->GetPolygonVertex(i, j); FbxVector4 pos = lControlPoints[lControlPointIndex]; current_model[vertex_index].x = pos.mData[0] - pivot_offset[0]; current_model[vertex_index].y = pos.mData[1] - pivot_offset[1]; current_model[vertex_index].z = pos.mData[2]- pivot_offset[2]; FbxVector4 vertex_normal; pMesh->GetPolygonVertexNormal(i,j, vertex_normal); current_model[vertex_index].nx = vertex_normal.mData[0]; current_model[vertex_index].ny = vertex_normal.mData[1]; current_model[vertex_index].nz = vertex_normal.mData[2]; //read in UV data FbxStringList lUVSetNameList; pMesh->GetUVSetNames(lUVSetNameList); //get lUVSetIndex-th uv set const char* lUVSetName = lUVSetNameList.GetStringAt(0); const FbxGeometryElementUV* lUVElement = pMesh->GetElementUV(lUVSetName); if(!lUVElement) continue; // only support mapping mode eByPolygonVertex and eByControlPoint if( lUVElement->GetMappingMode() != FbxGeometryElement::eByPolygonVertex && lUVElement->GetMappingMode() != FbxGeometryElement::eByControlPoint ) return; //index array, where holds the index referenced to the uv data const bool lUseIndex = lUVElement->GetReferenceMode() != FbxGeometryElement::eDirect; const int lIndexCount= (lUseIndex) ? lUVElement->GetIndexArray().GetCount() : 0; FbxVector2 lUVValue; //get the index of the current vertex in control points array int lPolyVertIndex = pMesh->GetPolygonVertex(i,j); //the UV index depends on the reference mode //int lUVIndex = lUseIndex ? lUVElement->GetIndexArray().GetAt(lPolyVertIndex) : lPolyVertIndex; int lUVIndex = pMesh->GetTextureUVIndex(i, j); lUVValue = lUVElement->GetDirectArray().GetAt(lUVIndex); current_model[vertex_index].tu = (float)lUVValue.mData[0]; current_model[vertex_index].tv = (float)lUVValue.mData[1]; vertex_index ++; } } float v1[3], v2[3], v3[3]; v1[0] = current_model[vertex_index - 3].x; v1[1] = current_model[vertex_index - 3].y; v1[2] = current_model[vertex_index - 3].z; v2[0] = current_model[vertex_index - 2].x; v2[1] = current_model[vertex_index - 2].y; v2[2] = current_model[vertex_index - 2].z; v3[0] = current_model[vertex_index - 1].x; v3[1] = current_model[vertex_index - 1].y; v3[2] = current_model[vertex_index - 1].z; collision_model->addTriangle(v1,v2,v3);

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• Loadbalancing Questions

  - by Van Holtz

  I have been learning networking for about 4 months. Wrote a single standalone Multiplayer server and succeeded with authoritative approach. Now I want to extend it by splitting the single server into clusters to allow even more players to log in to avoid latency issues. Now I have protyped the Loadbalancing server and its running pretty good so far. This is my architecture, I have a master server which acts as a proxy, every sub servers(chat, login, game) connect to the master server as well as all the clients. when a client connects, Client Request: Send Request - MS(Master) - Decides which SS(SubServer) to forward to - Forwards Request to SS - SS - Analyze Message - Send Response to MS - Decides which Client to forward to - Forwards Response to Client Well, it looks like its going through lots of stages. it takes double the time to process the message than a single server approach. i feel like my model isnt the best or i may be wrong. is there any better model or the one they use in professional games? I still want a Master-SubServer approach. I just want to clarify that I'm going in the right direction before writing all my codes. Thanks for any answer :)

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• PHP Battle System for RPG game

  - by Jay

  I posted this a while ago on stackoverflow, they thought it would be better place here, I agree. Essentially I know what I want to accomplish, and I have something to the effect of what I want but I am not satisfied with it. Here's the problem. Each user has some states: STR (how hard they hit), DEF (dodging/blocking attacks), SPD (when they can strike), and STAMINA (basically their endurance in game, if this runs out they can no longer fight and lose) What I need is something like this: UserA Stats: STR: 1,000 DEF: 2500 SPD: 2000 (HP: 1000/1000) UserB Stats: STR: 1,500 DEF: 500 SPD: 4000 (HP: 1000/1000) Because the second user has double the speed, he lands twice the amount of hits on the first user, before he gets hit. Because he has less strength than the first users defence, he will do no, to little damage. This is how the battle would theoretically go: UserB strikes UserA for 0 damage UserB strikes UserA for 0 damage UserA strikes UserB for 500 damage UserB strikes UserA for 0 damage UserB strikes UserA for 0 damage UserA strikes UserB for 500 damage, and sends him to the hospital! I was using this code, which is buggy, and not efficient, I just need a better way to do this: http://pastebin.com/15LiQQuJ Oh, and if anyone has some good ideas on how to improve the concept that would be cool too! It's not that elaborate so I'll be thinking of all sorts of things to make it more dynamic. Thanks.

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• Sources of NetBeans Gradle Plugin

  - by Geertjan

  Here is where you can find the sources of the latest and greatest NetBeans Gradle plugin: http://java.net/projects/nb-api-samples/sources/api-samples/show/versions/7.1/misc/GradleSupport To use it, download the sources above, open the sources into the IDE (which must be 7.1.1 or above), then you'll have a NetBeans module. Right-click it to run the module into a new instance of NetBeans IDE. In the Options window's Miscellaneous tab, there's a Gradle subtab for setting the Gradle location. In the New File dialog, in the Other category, you'll find a template named "Empty Gradle file". Make sure to name it "build" and to put it in the root directory of the application (by leaving the Folder field empty, you're specifying it should be created in the root directory). You'll then be able to expand the build.gradle file: Double-click a task to run it. When you open the file, it opens in the Groovy editor, if the Groovy editor is installed. When you make changes in the file, the list of tasks, shown above, is automatically recreated. It's at a really early stage of development and it would be great if developers out there would be interested in adding more features to it.

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• Burg Custom Icons work only with specific themes

  - by el10780

  I have made a custom icon for burg loader for my Lenovo Recovery Partition.I have made 3 icons : large_qdrive.png (128 X 128 pixels) small_qdrive.png (24 X 24 pixels) grey_qdrive.png (128 x 128 pixels) The .png icons that I created I made them using gimp from a qdrive.ico file that I found in the Lenovo Recovery Partition. I transferred the icons to the /boot/burg/themes/icons folder and I added to the class list of the grey,large,small and the hover files the following lines : -qdrive { image = "$$/large_qdrive.png" } in the large file -qdrive { image = "$$/small_qdrive.png" } in the small file -qdrive { image = "$$/grey_qdrive.png" } in the grey file -qdrive { image = "$$/grey_qdrive.png:$$/large_qdrive.png" } in the hover file I ran sudo update-burg and after that I modified the following line in the burg.cfg file : menuentry "Windows 7 (loader) (on /dev/sda2)" --class windows --class os { to menuentry "Windows 7 (loader) (on /dev/sda2)" --class qdrive --class os { and I also tried to change the title for the Lenovo Recovery Partition,so I tried this as well: menuentry "Lenovo Recovery Partition (on /dev/sda2)" --class qdrive --class os { None of this tries enforced actually burg loader to use the custom icon that I made and I can't figure out why. I have to mention also that there are a few themes that I have installed in burg which actually are able to use the small_qdrive.png icon that I made,but all the others which use either the large_qdrive.png or the grey_qdrive.png weren't able to use the custom icons. I have double checked for typos in all the files that I have created or I modified,so I am pretty sure that I haven't misspelled anything. I have checked also the title of the custom icons that I made and neither of them have a typo. I have looked also if there are any other folder that the themes might use to retrieve the icons,but it seems that all of them except for **Fortune** theme,which I downloaded from OMG!UBUNTU,use the icons folder which is located in /boot/burg/themes/icons I tried to add the custom icons to the icons folder of the theme **Fortune**,but still nothing happened.

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• Are web application usability issues equal to website usability issues?

  - by Kor

  I've been reading two books about web usability issues and tests (Rocket Surgery Made Easy¹ and Prioritizing Web Usability²) and they claim some strategies and typical problems about website usability and how to lead them. However, I want to do a web application, and I think I lost track of what I am trying to solve. These two books claim to work with raw websites (e-commerce, business sites, even intranet), but I'm not sure if everything about web usability is applicable to web application usability. They sure talk about always having available (and usable) the Back button, to focus on short information rather than big amounts of text, etc., but they could be inaccurate in deeper problems that may be easier (or just skippable) in regular websites. Has anybody some experience in this field and could tell me if both web applications and websites share their usability issues? Thanks in advance Edit: Quoting Wikipedia, a website is a collection of related web pages containing images, videos or other digital assets, and a web application is an application that is accessed over a network such as the Internet or an intranet. To sum up, both shows/lets you search/produce information but websites are "simple" in interaction and keep the classics of websites (one-click actions) and the other one is closer to desktop applications in the meaning of their uses and ways of interaction (double click, modal windows, asynchronous calls [to keep you in the same "environment" instead of reloading it] etc.). I don't know if this clarifies the difference. Edit 2: Quoting @Victor and myself, a website is anything running in your browser, but a web application is somewhat running in your browser that could be running in your desktop, with similar behaviors and features. Gmail is a web application that could replace Outlook. GDocs could replace Office. Grooveshark could replace your music player, etc.

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• Procurement Community Live Chat December 13th on Implementing AME with Purchase Orders

  - by LuciaC

  Do you still have questions on setting up the Approval Management Engine (AME) for Purchase Orders after attending the AME Webcast? Or maybe you are new to this topic and need more information?  Don’t miss our Procurement Community Live Chat on December 13th from 7:00 am to 11:00 am EST. Proactive Support and Development will be available to answer questions.You can access the main Oracle Communities page at http://communities.oracle.com (If you are enrolled, the Procurement community will be listed on your left.   If you're not already enrolled in the Procurement community, you can do so by clicking on the link Edit Subscriptions). OR you can use these alternative steps:From "My Oracle Support" as follows:    Log into My Oracle Support.    Click on the 'Community' link at the top of the page.    Click in 'Find a Community' field and enter Procurement.    Double click on Procurement in the list.    Click on the 'Create a Community Post' button and submit your question.Then in the ‘Procurement Featured Discussions’ section, drill down on the following thread and post your question.  We are looking forward to hearing from you!

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• Floating point undesireable in highly critical code?

  - by Kirt Undercoffer

  Question 11 in the Software Quality section of "IEEE Computer Society Real-World Software Engineering Problems", Naveda, Seidman, lists fp computation as undesirable because "the accuracy of the computations cannot be guaranteed". This is in the context of computing acceleration for an emergency braking system for a high speed train. This thinking seems to be invoking possible errors in small differences between measurements of a moving object but small differences at slow speeds aren't a problem (or shouldn't be), small differences between two measurements at high speed are irrelevant - can there be a problem with small roundoff errors during deceleration for an emergency braking system? This problem has been observed with airplane braking systems resulting in hydroplaning but could this actually happen in the context of a high speed train? The concern about fp errors seems to not be well-founded in this context. Any insight? The fp is used for acceleration so perhaps the concern is inching over a speed limit? But fp should be just fine if they use a double in whatever implementation language. The actual problem in the text states: During the inspection of the code for the emergency braking system of a new high speed train (a highly critical, real-time application), the review team identifies several characteristics of the code. Which of these characteristics are generally viewed as undesirable? The code contains three recursive functions (well that one is obvious). The computation of acceleration uses floating point arithmetic. All other computations use integer arithmetic. The code contains one linked list that uses dynamic memory allocation (second obvious problem). All inputs are checked to determine that they are within expected bounds before they are used.

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• When module calling gets ugly

  - by Pete

  Has this ever happened to you? You've got a suite of well designed, single-responsibility modules, covered by unit tests. In any higher-level function you code, you are (95% of the code) simply taking output from one module and passing it as input to the next. Then, you notice this higher-level function has turned into a 100+ line script with multiple responsibilities. Here is the problem. It is difficult (impossible) to test that script. At least, it seems so. Do you agree? In my current project, all of the bugs came from this script. Further detail: each script represents a unique solution, or algorithm, formed by using different modules in different ways. Question: how can you remedy this situation? Knee-jerk answer: break the script up into single-responsibility modules. Comment on knee-jerk answer: it already is! Best answer I can come up with so far: create higher-level connector objects which "wire" modules together in particular ways (take output from one module, feed it as input to another module). Thus if our script was: FooInput fooIn = new FooInput(1, 2); FooOutput fooOutput = fooModule(fooIn); Double runtimevalue = getsomething(fooOutput.whatever); BarInput barIn = new BarInput( runtimevalue, fooOutput.someOtherValue); BarOutput barOut = barModule(BarIn); It would become with a connector: FooBarConnectionAlgo fooBarConnector = new fooBarConnector(fooModule, barModule); FooInput fooIn = new FooInput(1, 2); BarOutput barOut = fooBarConnector(fooIn); So the advantage is, besides hiding some code and making things clearer, we can test FooBarConnectionAlgo. I'm sure this situation comes up a lot. What do you do?

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• Handling Types for Real and Complex Matrices in a BLAS Wrapper

  - by mga

  I come from a C background and I'm now learning OOP with C++. As an exercise (so please don't just say "this already exists"), I want to implement a wrapper for BLAS that will let the user write matrix algebra in an intuitive way (e.g. similar to MATLAB) e.g.: A = B*C*D.Inverse() + E.Transpose(); My problem is how to go about dealing with real (R) and complex (C) matrices, because of C++'s "curse" of letting you do the same thing in N different ways. I do have a clear idea of what it should look like to the user: s/he should be able to define the two separately, but operations would return a type depending on the types of the operands (R*R = R, C*C = C, R*C = C*R = C). Additionally R can be cast into C and vice versa (just by setting the imaginary parts to 0). I have considered the following options: As a real number is a special case of a complex number, inherit CMatrix from RMatrix. I quickly dismissed this as the two would have to return different types for the same getter function. Inherit RMatrix and CMatrix from Matrix. However, I can't really think of any common code that would go into Matrix (because of the different return types). Templates. Declare Matrix<T> and declare the getter function as T Get(int i, int j), and operator functions as Matrix *(Matrix RHS). Then specialize Matrix<double> and Matrix<complex>, and overload the functions. Then I couldn't really see what I would gain with templates, so why not just define RMatrix and CMatrix separately from each other, and then overload functions as necessary? Although this last option makes sense to me, there's an annoying voice inside my head saying this is not elegant, because the two are clearly related. Perhaps I'm missing an appropriate design pattern? So I guess what I'm looking for is either absolution for doing this, or advice on how to do better.

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• Oracle Payables Accounting Information Centres

  - by user793553

  Payables Accounting Information Centers Do you have error when trying to create accounting in Payables ? Do you have questions about Payables Accounting ? The following new Information centers include solutions to many of the issues and answers to your questions.          Overview  > Hot Topics > Resources Information Center: Oracle Payables Accounting R12 ( Doc ID 1476284.2) Under Hot Topics: Include details about: Recommended patches, new solution documents, GDF patches, Announcements, links to Communities. Under Resources: Popular Troubleshooting documents, Accounting Documentation, popular Knowledge documents, links to other info centers.  Use   Information Center: Using Oracle Payables Accounting (Doc ID 1478842.2) Include product documentation, Reconciliation, Upgrade, Performance, Undo Accounting, Trace and FND Debug, and Diagnostics. Troubleshoot Information Center: Troubleshooting Oracle Payables Accounting (Doc ID 1478863.2) Include Troubleshooting documents, Period close, GL Transfer, Trial Balance, Budget, Health Check. Do you have other questions..............? Post your question to the Oracle Payables Community 1. Log into My Oracle Support. 2. Click on the 'Community' link at the top of the page. 3. Click in 'Find a Community' field and enter Payables  4. Double click on Payables in the list. OR   Click Here

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• Is there an excuse for excessively short variable names?

  - by KChaloux

  This has become a large frustration with the codebase I'm currently working in; many of our variable names are short and undescriptive. I'm the only developer left on the project, and there isn't documentation as to what most of them do, so I have to spend extra time tracking down what they represent. For example, I was reading over some code that updates the definition of an optical surface. The variables set at the start were as follows: double dR, dCV, dK, dDin, dDout, dRin, dRout dR = Convert.ToDouble(_tblAsphere.Rows[0].ItemArray.GetValue(1)); dCV = convert.ToDouble(_tblAsphere.Rows[1].ItemArray.GetValue(1)); ... and so on Maybe it's just me, but it told me essentially nothing about what they represented, which made understanding the code further down difficult. All I knew was that it was a variable parsed out specific row from a specific table, somewhere. After some searching, I found out what they meant: dR = radius dCV = curvature dK = conic constant dDin = inner aperture dDout = outer aperture dRin = inner radius dRout = outer radius I renamed them to essentially what I have up there. It lengthens some lines, but I feel like that's a fair trade off. This kind of naming scheme is used throughout a lot of the code however. I'm not sure if it's an artifact from developers who learned by working with older systems, or if there's a deeper reason behind it. Is there a good reason to name variables this way, or am I justified in updating them to more descriptive names as I come across them?

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• forward motion car physics - gradual slow

  - by spartan2417

  Im having trouble creating realistic car movements in xna 4. Right now i have a car going forward and hitting a terminal velocity which is fine but when i release the up key i need to the car to slow down gradually and then come to a stop. Im pretty sure this is easy code but i cant seem to get it to work the code - update if (Keyboard.GetState().IsKeyDown(Keys.Up)) { double elapsedTime = gameTime.ElapsedGameTime.Milliseconds; CalcTotalForce(); Acceleration = Vector2.Divide(CalcTotalForce(), MASS); Velocity = Vector2.Add(Velocity, Vector2.Multiply(Acceleration, (float)(elapsedTime))); Position = Vector2.Add(Position, Vector2.Multiply(Velocity, (float)(elapsedTime))); } added functions public Vector2 CalcTraction() { //Traction force = vector direction * engine force return Vector2.Multiply(forwardDirection, ENGINE_FORCE); } public Vector2 CalcDrag() { //Drag force = constdrag * velocity * speed return Vector2.Multiply(Vector2.Multiply(Velocity, DRAG_CONST), Velocity.Y); } public Vector2 CalcRoll() { //roll force = const roll * velocity return Vector2.Multiply(Velocity, ROLL_CONST); } public Vector2 CalcTotalForce() { //total force = traction + (-drag) + (-rolling) return Vector2.Add(CalcTraction(), Vector2.Add(-CalcDrag(), -CalcRoll())); } anyone have any ideas?

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• Calculating a child object's Position, Rotation and Scale values?

  - by Sergio Plascencia

  I am making my own game editor, but have encountered the following problem: I have two objects, A and B. A's initial values: Position: (3,3,3), Rotation: (45,10,0), Scale(1,2,2.5) B's initial values: Position: (1,1,1), Rotation: (10,34,18), Scale(1.5,2,1) If I now make B a child of A, I need to re-calculate the B's Position, Rotation and Scale relative to A such that it maintains its current position, rotation and scale in world coordinates. So B's position would now be (-2, -2, -2) since now A is its center and (-2, -2, -2) will keep B in the same position. I think I got the Position and scale figured out, but not rotation. So I opened Unity and ran the same example and I noticed that when making a child object, the child object did not move at all. but had its Position, Rotation and Scale values changed relative to the parent. For example: Unity (Parent Object "A"): Position: (0,0,0) Rotation: (45,10,0) Scale: (1,1,1) Unity (Child Object "B"): Position: (0,0,0) Rotation: (0,0,0) Scale: (1,1,1) When B becomes a child of A, it's rotation values become: X: -44.13605 Y: -14.00195 Z: 9.851074 If I plug the same rotation values into the B object in my editor, the object does not move at all. How did Unity arrive at those rotation values for the child? What are the calculations? If you can put all the equations for the Position, Rotation or Scale then I can double check I am doing it correctly but the Rotation is what I really need.

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• 2D scene graph not transforming relative to parent

  - by Dr.Denis McCracleJizz

  I am currently in the process of coding my own 2D Scene graph, which is basically a port of flash's render engine. The problem I have right now is my rendering doesn't seem to be working properly. This code creates the localTransform property for each DisplayObject. Matrix m_transform = Matrix.CreateRotationZ(rotation) * Matrix.CreateScale(scaleX, scaleY, 1) * Matrix.CreateTranslation(new Vector3(x, y, z)); This is my render code. float dRotation; Vector2 dPosition, dScale; Matrix transform; transform = this.localTransform; if (parent != null) transform = localTransform * parent.localTransform; DecomposeMatrix(ref transform, out dPosition, out dRotation, out dScale); spriteBatch.Draw(this.texture, dPosition, null, Color.White, dRotation, new Vector2(originX, originY), dScale, SpriteEffects.None, 0.0f); Here is the result when I try to add the Stage then to the stage a First DisplayObjectContainer and then a second one. It may look fine but the problem lies in the fact that I add a first DisplayObjectContainer at (400,400) and the second one within it (that's the smallest one) at position (0,0). So he should be right over its parent but he gets render within the parent at the same position the parent has (400, 400) for some reason. It's just as if I double the parent's localMatrix and then render the second cat there. This is the code i use to loop through every childs. base.Draw(spriteBatch); foreach (DisplayObject childs in _childs) { childs.Draw(spriteBatch); }

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• How to Pin Any File to the Start Screen in Windows 8

  - by Taylor Gibb

  By default Windows 8 only allows you to pin a few file types to the Start Screen. Read on to find out how you can change that by editing the registry. How to Pin Any File to the Start Screen in Windows 8 Press the Win + R keyboard combination to open a run box, then type notepad and press enter. When notepad opens, paste the following into the new document: Windows Registry Editor Version 5.00 [HKEY_CLASSES_ROOT\*\shell\pintostartscreen] “MUIVerb”=”@shell32.dll,-51201″ “NeverDefault”=”" “Description”=”@shell32.dll,-51202″ “MultiSelectModel”=”Single” [HKEY_CLASSES_ROOT\*\shell\pintostartscreen\command] “DelegateExecute”=”{470C0EBD-5D73-4d58-9CED-E91E22E23282}” Then click on the File menu item and select save as… Before you go any further, change the Save as type to All Files. Then give your file a name ending in .reg and click Save. PinToStartHack.reg To use the hack, just double click on the .reg file you just created. When you are prompted about whether you want to continue, click Yes. Now you can pin any file to the Start Screen. Undo the Change If you ever wish to undo the change, press the Win + R keyboard combination and type regedit, then press enter. Then drill down into: HKEY_CLASSES_ROOT\*\shell\ Finally delete the pintostartscreen key. That’s all there is to it. How to Factory Reset Your Android Phone or Tablet When It Won’t Boot Our Geek Trivia App for Windows 8 is Now Available Everywhere How To Boot Your Android Phone or Tablet Into Safe Mode

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• lvm disappeared after disc replacement on raid10

  - by user142295

  here my problem: I am running ubuntu 12.04 on a raid10 (4 disks), on top of which I installed an lvm with two volume groups (one for /, one for /home). The layout of the disks are as follows: Disk /dev/sda: 1500.3 GB, 1500301910016 bytes 255 heads, 63 sectors/track, 182401 cylinders, total 2930277168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x0003f3b6 Device Boot Start End Blocks Id System /dev/sda1 * 63 481949 240943+ 83 Linux /dev/sda2 481950 2910640634 1455079342+ fd Linux raid autodetect /dev/sda3 2910640635 2930272064 9815715 82 Linux swap / Solaris Disk /dev/sdb: 1500.3 GB, 1500301910016 bytes 255 heads, 63 sectors/track, 182401 cylinders, total 2930277168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00069785 Device Boot Start End Blocks Id System /dev/sdb1 63 2910158684 1455079311 fd Linux raid autodetect /dev/sdb2 2910158685 2930272064 10056690 82 Linux swap / Solaris Disk /dev/sdc: 1500.3 GB, 1500301910016 bytes 255 heads, 63 sectors/track, 182401 cylinders, total 2930277168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00000000 Device Boot Start End Blocks Id System /dev/sdc1 63 2910158684 1455079311 fd Linux raid autodetect /dev/sdc2 2910158685 2930272064 10056690 82 Linux swap / Solaris Disk /dev/sdd: 1500.3 GB, 1500301910016 bytes 255 heads, 63 sectors/track, 182401 cylinders, total 2930277168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x000f14de Device Boot Start End Blocks Id System /dev/sdd1 63 2910158684 1455079311 fd Linux raid autodetect /dev/sdd2 2910158685 2930272064 10056690 82 Linux swap / Solaris The first disk (/dev/sda) contains the /boot partition on /dev/sda1. I use grub2 to boot the system off this partition. On top of this raid10 I installed two volume groups, one for /, one for /home. This system worked well, I even exchanged two disks during the last two years. It always worked. But not this time. For the first time, /dev/sda broke. I do not know if this is an issue – I know I would have struggled anyways to overcome the problem with /boot installed on that disk and grub2 installed on the mbr of /dev/sda. Anyways, I did what I always did: start knoppix fire up the raid sudo mdadm --examine -scan which returns ARRAY /dev/md127 UUID=0dbf4558:1a943464:132783e8:19cdff95 start it up sudo mdadm --assemble /dev/md127 fail the failing disk (smart event) sudo mdadm /dev/md127 --fail /dev/sda2 remove the failing disk sudo mdadm /dev/md127 --remove /dev/sda2 stop the raid sudo mdadm -S /dev/md127 take out the disk replace it with a new one create the same partitions as on the failling one add it to the raid sudo mdadm --assemble /dev/md127 sudo mdadm /dev/md127 --add /dev/sda2 wait 4 hours All looks fine: cat /proc/mdstat returns: Personalities : [raid10] md127 : active raid10 sda2[0] sdd1[3] sdc1[2] sdb1[1] 2910158464 blocks 64K chunks 2 near-copies [4/4] [UUUU] unused devices: <none> and sudo mdadm --detail /dev/md127 returns /dev/md127: Version : 0.90 Creation Time : Wed Jun 10 13:08:46 2009 Raid Level : raid10 Array Size : 2910158464 (2775.34 GiB 2980.00 GB) Used Dev Size : 1455079232 (1387.67 GiB 1490.00 GB) Raid Devices : 4 Total Devices : 4 Preferred Minor : 127 Persistence : Superblock is persistent Update Time : Thu Mar 21 16:27:40 2013 State : clean Active Devices : 4 Working Devices : 4 Failed Devices : 0 Spare Devices : 0 Layout : near=2 Chunk Size : 64K UUID : 0dbf4558:1a943464:132783e8:19cdff95 (local to host Microknoppix) Events : 0.4824680 Number Major Minor RaidDevice State 0 8 2 0 active sync /dev/sda2 1 8 17 1 active sync /dev/sdb1 2 8 33 2 active sync /dev/sdc1 3 8 49 3 active sync /dev/sdd1 However, there is no trace of the volume groups. Rebooting into knoppix does not help Restarting the old system (I actually replugged and re-added the failing disk for that – the system begins to start, but then fails to see the / partition – no wonder if the volume group is gone) does not help. sudo vgscan, sudo vgdisplay, sudo lvs, sudo lvdisplay, sudo vgscan –mknodes all returned No volume groups found. I am completely at a loss. Can anyone tell me if and how I can recover my data? Thanks in advance!

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• The tale of how the PowerShell CmdLets got installed with Azure SDK 1.4

  - by Enrique Lima

  I installed the Azure SDK 1.4 while rebuilding my laptop and ran the installation for the Windows Azure Service Management PowerShell CmdLets. Kicked off the installation script for the WASM PowerShell CmdLets by locating the path to which WASM PowerShell CmdLets was deployed to. Double clicked the startHere command. It will then open the WASM installation dialog. Click Next. Click Next. Notice the red x next to the Azure SDK 1.3, the problem is I have SDK 1.4 Here is the workaround, I go back to the location of the deployed WASM sources. Go into the setup path, then scripts>dependencies>check. Now, locate the CheckAzureSDK.ps1 file, and right-click, then edit. This is the content in the ps1 file, it check for the specific version of the Azure SDK, in this case, it is looking for version 1.3.11133.0038. We need for it to check for version 1.4.20227.1419 Now, save your ps1 file, go back to the open WASM install dialog, and click rescan. This time it should pass, then click next. A Command prompt window will appear, click any key. This completes the installation, click Close.

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