Jatrix

A poweful library for performing different operations with matrices

Hi there! Jatrix is a new library for performing different operations with matrices. There are some operations with matrices: summation, subtraction, multiplying, trasposition, inversion, solving a system of linear equations, decompostitions, etc. The library is focused on performance and simplicity. In the benchmarking package you find benchmarks of some solutions.

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Features

There are some features of Jatrix library:

• A straightforward API.
• Strassen multiplying (more faster than default matrix product, you can see the result of comparison at samples directory of the matrix multiplications).
• Comfortable output methods. Printing out to .md, .txt and .html files in a pretty form.
• A vast numbers of methods for enjoyable development.

Download

To download the library you need to use the following dependencies:

• Apache Maven:

  <dependency>
    <groupId>com.github.danilos1</groupId>
    <artifactId>jatrix</artifactId>
    <version>0.1</version>
  </dependency>

• Gradle Groovy DSL: implementation 'com.github.danilos1:jatrix:0.1'

The Jatrix API is consisted of the following sections:

• core section is basic package, stores main classes of the library such as Matrix, Matrices, MatrixIterator etc.

For instance, let's initialize some matrix and perform matrix product:

Matrix a = new Matrix(new double[][]{
     { 1, 7, 3},
     {-5, 0, 9}
});
    
Matrix b = new Matrix(new double[][]{
     {8, 10},
     {3,-12},
     {1, -7},
});
    
Matrix result = Matrices.mul(a, b);
System.out.println(result.prettyOut());

• exceptions section includes exceptions of the library.
• In solvers section you'll find tools for solving linear equations.

To demonstrate one of solvers, let's solve the following system of linear equation:

{ -5x1 + 3x2 - x3 = 1
{ 8x2 + 2x3 = -5
{ 12x1 + 7x2 - 6*x3 = 6

Matrix coefficients = new Matrix(new double[][]{
   { -5, 3, -1 },
   {  0, 8,  2 },
   { 12, 7, -6 },
});

double[] b = {1, -5, 6};

CramerSolver solver = new CramerSolver(coefficients, b);
System.out.println(solver);

• decompositions section is used for decomposing some matrix (See Matrix decomposition)

For example, let's decompose the matrix above:

  Matrix a = new Matrix(new double[][]{
      { -5, 3, -1 },
      {  0, 8,  2 },
      { 12, 7, -6 },
   });
   
   LUDecomposition lu = new LUDecomposition(a);
   System.out.println(lu.getL());
   System.out.println(lu.getU());
   System.out.println(lu.det());

• conversion block is used for changing a matrix somewise (swap matrix rows or columns, etc)
• To find out some statistics such as maximum or minimum by row or column you can use statistics section.
• printer block is used for printing out a matrix into a .txt, .md or .html files. E.g. let's print out a random matrix to html file:

    Matrix a = new Matrix(new double[][]{
        { -5, 3, -1 },
        {  0, 8,  2 },
        { 12, 7, -6 },
     });
  
     MatrixPrinter printer = new MatrixPrinter(a);
     try {
        a.saveAsHtml(new File(C://...matrix.html));
     } catch (FileNotFoundException e) {
        e.printStackTrace();
     }
  

  And matrix.html looks as the following page:

For detail information you should go to the Documentation page.

Documentation

All Jatrix API is stored in JavaDoc.

License

Jatrix code is under MIT License