LinAlg API: Full List of Features

New Feautures: Eigenvalues and triple scalar product

The next release of LinAlg API will provide methods to compute Eigenvalues and the triple scalar product.

Eigenvalues and the triple scalar product are common and helpful mathematical features that are useful for solving a lot of common math problems.

The Eigenvalues are computed by solving the linear equation det(A-lambda*In) where A is a Matrix, lambda a free parameter and In the identity matrix. We can simplify this by simply determening the det(a) of the Matrix with a parameter and omitting the multplication with the identity matrix since a value multplied by 1 results in the same value.

And the multiplication by the identity matrix just means: multiply all diagonal components of the matrix by 1 that is m11, m22, m33 and m44 if you have a 4x4 matrix.

The triple scalar product is simply computed by computing the volume of three 3D Vectors by multiplying all components of the three 3D Vectors and perform some + and - operations on them.

Yet Another Closures Proposal

First: Getting rid of =>

Basically, when i read all the proposals, comments and pros and cons on closures in Java the first thing i would get rid of is the obviously redundant => declaration.

So in case of block statements the following would be allowed:

{
 int x = 0;
 int y = 3;
 int sum:= x+ y;
}

As i understood it right, => has at least two meanings. It means return for functions and := or = in the other case.

Replace => by := for assignments

I would use := for assignments rather than => simply because := is more naturial to mathematicians and logicians and is usually used to describe an assignment in math and logics. This could be used as outlined above:

{
 int x = 4;
 int y = 3;
 int z = 3;
 int sum:=x+y+z; //assignment
}

Use a function keyword instead of {int, int => int} syntax

For the function declaration, i would suggest to use a keyword rather than a symbol. Why not invent a function keyword that has a similar meaning like => i.g.:

public int function add(int x, int y){
return x + y;
}

In the other case, i would use := instad of => because the arrow direction implies to read it left to right rather than right to left and there is no <= to represant the invert direction.

Use a block keyword to declare block statements

Rather than just simply type closures i would invent a block keyword that defines a block of anonymous statements:

//only valid for anonymous block statements, not be used in loops 
//itereations

block{
 int x = 3;
 int y = 4;

}

So with these language features you could write a simple to read Java code that is clear and understandable by everyone:

class MyClass{
 //declare a function type
 public int function add(int x, int y){
    return x + y;
 }
 public int function sub(int x, int y){
  return x - y;
 }
 public void function(List<int> intList){
    for(int i = 0; i < 10; i++){
        intList.add(i);
     }
  }
 public static void main(String[] args){
   
  //declare a closures block
   block{
     int x = 4;
     int y = 3;
    System.out.println("x + y" + (x+y));
    }
  }
 }

}

LinAlg API: 20 fellows make up a Community

20 Fellows make up a Community

The twentieth member has joined the LinAlg API community. Members background ranges from computer sciences and software engineers with up to 5 years of experience in Java programming and with industry background.

In particular in the last two month many people joined LinAlg API and asked for help in developing or porting LinAlg API to other platforms.

Thats a great news and i hope and will look forward to get more fellows that want to contribute and help improving LinAlg API. We are on a good way.

LinAlg API: Finished

LinAlg API: its finished

Yes. Finally, i got it done. LinAlg API now offers all the things i wanted to see it have. Sure, there are some things to do here and there but basically all features from my todo list are now implemented and exist at an almost complete level. The Quaternion class needs to be finished yet this is something i will do in the next couple of weeks however the Quaternion class already provides some basic operations for Quaternions you can work with with.

LinAlg API: Scope and Features

From the very beginning i wanted to write an almost complete linear algebra API that offers basic features to do linear algebra with Java. Now, lets have a short look at what features LinAlg API provides with this stable release:

• 2D and 3D Vector arithmetics
• Matrix operations - both array based and non array-based
• Complex Number operations
• Quaternions - still something on the todo list
• Algorithms - yes, there is a general Gaussian algorithm now
• Demos, Docs, Tutorials

Sure, there are some things you wont find in LinAlg API that some people may find useful yet the Todo list has not been closed :). Another important thing - that has nothing todo with its implementation - is the growing number of interesting people and developers that join the project. Some of them give feedback others not but its a good feeling to see that there are people that like the project and want to help make it better.

Sure, i am still looking for volunteers, testers and developers to test and help improve LinAlg API so if you are interested feel free to joint the project.

Demos, Docs, Tutorials

There are a few demos available that demonstrate the core features of LinAlg API, a tutorial for beginners and a whitepaper for those interested in background information. I will start writing a JCP for those interested in using LinAlg API for their own implementations. Basically using LinAlg API is rather simple - no matter if you use it for developing apps or to develop your own linear algebra API. I will provide more tutorials and information on implementation issues in the near future.