math.utils

Class Matrix

java.lang.Object

math.utils.Matrix

public class Matrix
extends Object

class Matrix

Constructor Summary

Constructors

Constructor and Description
Matrix() Construct a new Matrix, with 1 row and 1 column, initialized to 1.
Matrix(double[][] coef) Construct a new Matrix, initialized with the given coefficients.
Matrix(int nbRows, int nbCols) init a new Matrix with nbRows rows, and nbCols columns.

Method Summary

Modifier and Type	Method and Description
double	getCoef(int row, int col) return the coef. row and col are between 1 and the number of rows and columns.
int	getColumns() return the number of columns.
int	getRows() return the number of rows.
Matrix	getTranspose() get the transposed matrix, without changing the inner coefficients of the original matrix.
boolean	isSquare() return true if the matrix is square, i.e. the number of rows equals the number of columns.
double[]	multiplyWith(double[] coefs) return the result of the multiplication of the matrix with the given vector.
double[]	multiplyWith(double[] src, double[] res) return the result of the multiplication of the matrix with the given vector.
Matrix	multiplyWith(Matrix matrix) return the result of the multiplication of the matriux with another one.
void	setCoef(int row, int col, double coef) set the coef to the given value. row and col are between 1 and the number of rows and columns.
void	setToIdentity() Fill the matrix with zeros everywhere, except on the main diagonal, filled with ones.
double[]	solve(double[] vector) compute the solution of a linear system, using the Gauss-Jordan algorithm.
String	toString() return a String representation of the elements of the Matrix
void	transpose() transpose the matrix, changing the inner coefficients.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Matrix

public Matrix()

Construct a new Matrix, with 1 row and 1 column, initialized to 1.

Matrix

public Matrix(int nbRows,
              int nbCols)

init a new Matrix with nbRows rows, and nbCols columns.

Matrix

public Matrix(double[][] coef)

Construct a new Matrix, initialized with the given coefficients.

Method Detail

getCoef

public double getCoef(int row,
                      int col)

return the coef. row and col are between 1 and the number of rows and columns.

getRows

public int getRows()

return the number of rows.

getColumns

public int getColumns()

return the number of columns.

isSquare

public boolean isSquare()

return true if the matrix is square, i.e. the number of rows equals the number of columns.

setCoef

public void setCoef(int row,
                    int col,
                    double coef)

set the coef to the given value. row and col are between 1 and the number of rows and columns.

multiplyWith

public Matrix multiplyWith(Matrix matrix)

return the result of the multiplication of the matriux with another one. The content of the matrix is not modified.

multiplyWith

public double[] multiplyWith(double[] coefs)

return the result of the multiplication of the matrix with the given vector. The content of the matrix is not modified.

multiplyWith

public double[] multiplyWith(double[] src,
                             double[] res)

return the result of the multiplication of the matrix with the given vector. The content of the matrix is not modified.

transpose

public void transpose()

transpose the matrix, changing the inner coefficients.

getTranspose

public Matrix getTranspose()

get the transposed matrix, without changing the inner coefficients of the original matrix.

solve

public double[] solve(double[] vector)

compute the solution of a linear system, using the Gauss-Jordan algorithm. The inner coefficients of the matrix are not modified.

setToIdentity

public void setToIdentity()

Fill the matrix with zeros everywhere, except on the main diagonal, filled with ones.

toString

public String toString()

return a String representation of the elements of the Matrix

Overrides:

toString in class Object