Search Results

Search found 2258 results on 91 pages for 'abstract algebra'.

Page 10/91 | < Previous Page | 6 7 8 9 10 11 12 13 14 15 16 17  | Next Page >

  • In Search Data Structure And Algorithm Project Title Based on Topic

    - by Salehin Suhaimi
    As the title says, my lecturer gave me a project that i needed to finish in 3 weeks before final semester exams. So i thought i will start now. The requirement is to "build a simple program that has GUI based on all the chapter that we've learned." But i got stuck on WHAT program should i build. Any idea a program that is related to this chapter i've learned? Any input will help. list, array list, linked list, vectors, stacks, Queues, ADT, Hashing, Binary Search Tree, AVL Tree, That's about all i can remember. Any idea where can i start looking?

    Read the article

  • Trouble with Collada bones

    - by KyleT
    I have a Collada file with a rigged mesh. I've read the node tags in the library_visual_scenes tag and extracted the matrix for each node and stored everything in a hierarchical bone structure. My Matrix container is "row major", so I'd store the first float of a matrix tag in the 1st row, 1st column, the second in the 1st row, 2nd column, etc. From what I gather this is the Bind Pose Matrix. After that I went through the tag and extracted the float array in the source tag of the skin tag of the controller for the mesh. I stored each matrix from this float array in their corresponding Bone as the Inverse Bind Matrix. I also extracted the bind-shape-matrix and stored it. Now I'd like to draw the skeleton with OpenGL to see if everything is working correctly before I go about skinning. I iterate once over my bones and multiply a bone's Bind Pose Matrix by it's parents and store that. After that I iterate again over the bones and multiply the result of the previous matrix multiplication by the Inverse Bind Matrix and then by the Bind Shape Matrix. The results look something like this: [0.2, 9.2, 5.8, 1.2 ] [4.6, -3.3, -0.2, -0.1 ] [-1.8, 0.2, -4.2, -3.9 ] [0, 0, 0, 1 ] I've had to go to various sources to get the little understanding of Collada I have and books about 3d transform matricies can get pretty intense. I've hit a brick wall and if you could please read through this and see if there is something I'm doing wrong, and how I'd go about getting an X,Y,Z to draw a point for each of these joints once I've calculated the final transform, I'd really appreciate it.

    Read the article

  • Matrices: Arrays or separate member variables?

    - by bjz
    I'm teaching myself 3D maths and in the process building my own rudimentary engine (of sorts). I was wondering what would be the best way to structure my matrix class. There are a few options: Separate member variables: struct Mat4 { float m11, m12, m13, m14, m21, m22, m23, m24, m31, m32, m33, m34, m41, m42, m43, m44; // methods } A multi-dimensional array: struct Mat4 { float[4][4] m; // methods } An array of vectors struct Mat4 { Vec4[4] m; // methods } I'm guessing there would be positives and negatives to each. From 3D Math Primer for Graphics and Game Development, 2nd Edition p.155: Matrices use 1-based indices, so the first row and column are numbered 1. For example, a12 (read “a one two,” not “a twelve”) is the element in the first row, second column. Notice that this is different from programming languages such as C++ and Java, which use 0-based array indices. A matrix does not have a column 0 or row 0. This difference in indexing can cause some confusion if matrices are stored using an actual array data type. For this reason, it’s common for classes that store small, fixed size matrices of the type used for geometric purposes to give each element its own named member variable, such as float a11, instead of using the language’s native array support with something like float elem[3][3]. So that's one vote for method one. Is this really the accepted way to do things? It seems rather unwieldy if the only benefit would be sticking with the conventional math notation.

    Read the article

  • Portal View/Projection Matrix near plane

    - by melak47
    For RenderToTexture/Camera based portal rendering, the basics seems simple enough. However, with a free camera, most of the time it is going to be looking at such portals at an angle: Now a regular near clipping plane will not always work here, it will either intersect with the wall the portal is sitting on, or possibly with objects in front of the wall. The desired near clipping plane would be aligned like the portal, producing a view volume more like this: or this in 3D: So here is my question: How does one construct or "truncate" a view/projection matrix to achieve such an off-camera-normal (near) clipping plane?

    Read the article

  • Mouse pointer position to screen space

    - by Ylisar
    If I have a mouse pointer position in pixels of canvas, I can easily convert it to the -1..1 range for both X & Y by lerping by dividing with canvas dimensions. However, the problem is what I should put in Z & W if I want my screen space position to be on the near plane? The step afterwards would be for me to multiply by the inverse of view-projection to take me to world space, where I easily can construct a ray from the cameras world space position.

    Read the article

  • Should I implement an interface directly or have the superclass do it?

    - by c_maker
    Is there a difference between public class A extends AbstractB implements C {...} versus... public class A extends AbstractB {...} AbstractB implements C {...} I understand that in both cases, class A will end up conforming to the interface. In the second case, AbstractB can provide implementation for interface methods in C. Is that the only difference? If I do NOT want to provide an implementation for any of the interface methods in AbstractB, which style should I be using? Does using one or the other have some hidden 'documentation' purpose?

    Read the article

  • Vector transform equation explanation

    - by cyberdemon
    I'm trying to understand the maths of moving points in a 3d space by making a game written in C#. I'm looking at this wolfire blog series which explains some basic 3d maths. I've read the first two parts but am stuck on the 3rd. I know it's all really rudimentary stuff but I find Googling for help with equations really hard. The one I'm struggling with is: 0*(0.66,0.75) + 2*(-0.75, 0.66) = (-1.5, 1.3) How can anything multiplied by 0 not be 0? So my question is how does this look in code: x(a,b) + y(c,d) I know it's basic stuff but I just can't see it.

    Read the article

  • How to use reflection to get a default constructor?

    - by Qwertie
    I am writing a library that generates derived classes of abstract classes dynamically at runtime. The constructor of the derived class needs a MethodInfo of the base class constructor so that it can invoke it. However, for some reason Type.GetConstructor() returns null. For example: abstract class Test { public abstract void F(); } public static void Main(string[] args) { ConstructorInfo constructor = typeof(Test).GetConstructor( BindingFlags.NonPublic | BindingFlags.Public, null, System.Type.EmptyTypes, null); // returns null! } Note that GetConstructor returns null even if I explicitly declare a constructor in Test, and even if Test is not abstract.

    Read the article

  • abstract test case using python unittest

    - by gruszczy
    Is it possible to create an abstract TestCase, that will have some test_* methods, but this TestCase won't be called and those methods will only be used in subclasses? I think I am going to have one abstract TestCase in my test suite and it will be subclassed for a few different implementation of a single interface. This is why all test methods are the some, only one, internal method changes. How can I do it in elegant way?

    Read the article

  • Overriding an abstract method of base class

    - by jess
    Hi, I have an abstract class with some methods,including an abstract method(Execute()).This method is overridden in child class.Now, an event is raised(somewhere in application),and for this event there is a handler in base class.And,in this handler,I call Execute. Now, the method of chilobject is executed.I am bit confused,how this works under the hood?

    Read the article

  • real time scenario between interface/abstract class ?

    - by JavaUser
    Hi , Please give me a real time simple example for the below questions : Where to use interface rather abstract class Where to use abstract class rather interface I need code snippet for both . Which takes low memory and which performs well . Do I need to consider the design aspect also? What is the conceptual difference not the syntactical difference .

    Read the article

  • how to generate abstract for a video?

    - by George2
    Hello everyone, For a video file (e.g. wmv file or other format), I need to generate abstract for the video. The abstract is expected to be in text format. Any mature tools or algorithms? Better (not a must) if open source tools/SDKs so that I can modify for my special needs. thanks in advance, George

    Read the article

  • Generation of abstract class with JCodeModel

    - by SadJokerBY
    I'm trying to generate top-level abstract class with JCodeModel library, but I can't find any way to change class modifiers. It's possible for nested classes (JDefinedClass API provides methods that get modifiers as parameters). But for creation of top level classes I found only JCodeModel API methods that get fully qualified name with or without ClassType (class/interface/annotation/enum) as parameters. Does anybody can suggest me how to change modifiers of JDefinedClass to make it abstract?

    Read the article

  • is there a formal algebra method to analyze programs?

    - by Gabriel
    Is there a formal/academic connection between an imperative program and algebra, and if so where would I learn about it? The example I'm thinking of is: if(C1) { A1(); A2(); } if(C2) { A1(); A2(); } Represented as a sum of terms: (C1)(A1) + (C1)(A2) + (C2)(A1) + (C2)(A2) = (C1+C2)(A1+A2) The idea being that manipulation could lead to programatic refactoring - "factoring" being the common concept in this example.

    Read the article

  • Dynamically overriding an abstract method in c#

    - by ng
    I have the following abstract class public abstract class AbstractThing { public String GetDescription() { return "This is " + GetName(); } public abstract String GetName(); } Now I would like to implement some new dynamic types from this like so. AssemblyName assemblyName = new AssemblyName(); assemblyName.Name = "My.TempAssembly"; AssemblyBuilder assemblyBuilder = Thread.GetDomain().DefineDynamicAssembly(assemblyName, AssemblyBuilderAccess.Run); ModuleBuilder moduleBuilder = assemblyBuilder.DefineDynamicModule("DynamicThings"); TypeBuilder typeBuilder = moduleBuilder.DefineType(someName + "_Thing", TypeAttributes.Public | TypeAttributes.Class, typeof(AbstractThing)); MethodBuilder methodBuilder = typeBuilder.DefineMethod("GetName", MethodAttributes.Public | MethodAttributes.ReuseSlot | MethodAttributes.Virtual | MethodAttributes.HideBySig, null, Type.EmptyTypes); ILGenerator msil = methodBuilder.GetILGenerator(); msil.EmitWriteLine(selectionList); msil.Emit(OpCodes.Ret); However when I try to instantiate via typeBuilder.CreateType(); I get an exception saying that there is no implementation for GetName. Is there something I am doing wrong here. I can not see the problem. Also, what would be the restrictions on instantiating such a class by name? For instance if I tried to instantiate via "My.TempAssembly.x_Thing" would it be availble for instantiation without the Type generated?

    Read the article

  • EF 4.0 Code only assocation from abstract to derived

    - by Jeroen
    Using EF 4.0 Code only i want to make an assocation between an abstract and normal class. I have class 'Item', 'ContentBase' and 'Test'. 'ContentBase' is abstract and 'Test' derives from it. 'ContentBase' has a property 'Item' that links to an instance of 'Item'. So that 'Test.Item' or any class that derives from 'ContentBase' has an 'Item' navigation property. In my DB every record for Test has a matching record for Item. public class Item { public int Id { get; set;} } public abstract class ContentBase { public int ContentId { get; set;} public int Id { get; set;} public Item Item { get; set;} } public class Test : ContentBase { public string Name { get; set;} } now some init code public void SomeInitFunction() { var itemConfig = new EntityConfiguration<Item>(); itemConfig.HasKey(p => p.Id); itemConfig.Property(p => p.Id).IsIdentity(); this.ContextBuilder.Configurations.Add(itemConfig); var testConfig = new EntityConfiguration<Test>(); testConfig.HasKey(p => p.ContentId); testConfig.Property(p => p.ContentId).IsIdentity(); // the problem testConfig.Relationship(p => p.Item).HasConstraint((p, q) => p.Id == q.Id); this.ContextBuilder.Configurations.Add(testConfig); } This gives an error: A key is registered for the derived type 'Test'. Keys must be registered for the root type 'ContentBase'. anyway i try i get an error. What am i a doing wrong?

    Read the article

  • interface abstract in php real world scenario

    - by jason
    The goal is to learn whether to use abstract or interface or both... I'm designing a program which allows a user to de-duplicate all images but in the process rather then I just build classes I'd like to build a set of libraries that will allow me to re-use the code for other possible future purposes. In doing so I would like to learn interface vs abstract and was hoping someone could give me input into using either. Here is what the current program will do: recursive scan directory for all files determine file type is image type compare md5 checksum against all other files found and only keep the ones which are not duplicates Store total duplicates found at the end and display size taken up Copy files that are not duplicates into folder by date example Year, Month folder with filename is file creation date. While I could just create a bunch of classes I'd like to start learning more on interfaces and abstraction in php. So if I take the scan directory class as the first example I have several methods... ScanForFiles($path) FindMD5Checksum() FindAllImageTypes() getFileList() The scanForFiles could be public to allow anyone to access it and it stores in an object the entire directory list of files found and many details about them. example extension, size, filename, path, etc... The FindMD5Checksum runs against the fileList object created from scanForFiles and adds the md5 if needed. The FindAllImageTypes runs against the fileList object as well and adds if they are image types. The findmd5checksum and findallimagetypes are optionally run methods because the user might not intend to run these all the time or at all. The getFileList returns the fileList object itself. While I have a working copy I've revamped it a few times trying to figure out whether I need to go with an interface or abstract or both. I'd like to know how an expert OO developer would design it and why?

    Read the article

  • Unable to specify abstract classes in TPH hierarchy in Entity Framework 4

    - by Lee Atkinson
    Hi I have a TPH heirachy along the lines of: A-B-C-D A-B-C-E A-F-G-H A-F-G-I I have A as Abstract, and all the other classes are concrete with a single discriminator column. This works fine, but I want C and G to be abstract also. If I do that, and remove their discriminators from the mapping, I get error 3034 'Two entities with different keys are mapped to the same row'. I cannot see how this statement can be correct, so I assume it's a bug in some way. Is it possible to do the above? Lee

    Read the article

  • Abstract Forms using WinForms

    - by pm_2
    I’m trying to achieve a similar affect in a WinForms application as a master form does with ASP.NET. My initial thoughts on this were to create a base form and declare it as abstract, but the compiler doesn’t seem to let me do this. public abstract partial class Master : Form { public Master() { InitializeComponent(); } } So I have two questions: Why will the compiler not let me do this? Am I using the wrong syntax or is this a genuine restriction. Can anyone suggest a workaround or better way to do this? EDIT: InitializeComponent code: private void InitializeComponent() { this.components = new System.ComponentModel.Container(); this.mainMenu1 = new System.Windows.Forms.MainMenu(); this.Menu = this.mainMenu1; this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Dpi; this.Text = "Master"; this.AutoScroll = true; }

    Read the article

  • Defining a dd/mm/yyyy field within an abstract table model

    - by Simon Andi
    I have defined an abstract table model but one of the columns should house date values as dd/mm/yyyy format not sure how to do this. I have a external global file and have hard coded the dates as dd/mm/yyyy. How can I define this column within my abstract table model so that to only allow only dates having dd/mm/yyyy format. public class OptraderGlobalParameters { public static boolean DEBUG = true; //Set DEBUG = true for Debugging /*=========================*/ /*Table Array For Dividends*/ /*=========================*/ public static String[] columnNames = {"Date", "Dividend", "Actual", "Yield (%)" }; public static Object[][] data = { {"dd/mm/yyyy", new Double(5), new Boolean(false), new Boolean(false)}, {"dd/mm/yyyy", new Double(5), new Boolean(false), new Boolean(false)}, {"dd/mm/yyyy", new Double(5), new Boolean(false), new Boolean(false)}, {"dd/mm/yyyy", new Double(5), new Boolean(false), new Boolean(false)}, {"dd/mm/yyyy", new Double(5), new Boolean(false), new Boolean(false)}, }; }

    Read the article

< Previous Page | 6 7 8 9 10 11 12 13 14 15 16 17  | Next Page >