Class Matrix

java.lang.Object
  |
  +--Matrix

class Matrix

extends java.lang.Object

Field Summary

private double[][]

matrix

Constructor Summary

Matrix(double[][] data)
Construct a new vector with the given double values.

Matrix(int rowNum, int colNum)
Construct a new matrix with rowNum rows and colNum columns.

Method Summary

Matrix	add(Matrix other) Adds the other matrix to the current matrix and returns the result in a new Matrix object.
double	elementAt(int i, int j) Returns the value in the i'th row and j’th column in the matrix..
AlgebraicVector	gaussElimination() Retruns a vector that is the solution of the set of equations defined by this augmented matrix.
int	getColNum() Returns the number of columns in the matrix.
AlgebraicVector	getColVector(int i) Returns the i'th column in the matrix as an AlgebraicVector object.
int	getRowNum() Returns the number of rows in the matrix.
AlgebraicVector[]	getRowsAsVectors() Returns the rows of the matrix as an array of AlgebraicVectors
AlgebraicVector	getRowVector(int i) Returns the i'th row in the matrix as an AlgebraicVector object.
AlgebraicVector	mul(AlgebraicVector other) Computes the multiplication of the current matrix with the given vector.
Matrix	mul(double scalar) Computes the multiplication of the current matrix with the given scalar.
Matrix	mul(Matrix other) Multiplies the other matrix to the current matrix and returns the result in a new Matrix object.
void	setElementAt(double value, int i, int j) Sets the element in the i'th row and the j’th column to value.
void	setRowVector(AlgebraicVector vec, int i) Replace row i in the matrix with the given vector Assumes dimension of vector equal to the number of cols
Matrix	sub(Matrix other) Substracts the other matrix to the current matrix and returns the result in a new Matrix object.
private void	swapRows(int i, int j) Swaps between 2 rows in the matrix.
java.lang.String	toString() Returns a string representation of the vector in the following format: 2.0 3.1 5.4

Methods inherited from class java.lang.Object

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

Field Detail

matrix

private double[][] matrix

Constructor Detail

Matrix

public Matrix(int rowNum,
              int colNum)

Construct a new matrix with rowNum rows and colNum columns. Initial values are set to zero

Parameters:

rowNum - Number of Rows

colNum - Number of cols

Matrix

public Matrix(double[][] data)

Construct a new vector with the given double values.

Parameters:

data - A 2-dimentionl array of doubles

Method Detail

elementAt

public double elementAt(int i,
                        int j)

Returns the value in the i'th row and j’th column in the matrix.. Assumes that the indices i and j are legal, i.e 0

Parameters:

i - row i

j - col j

Returns:

double value found in (i,j) in the matrix

setElementAt

public void setElementAt(double value,
                         int i,
                         int j)

Sets the element in the i'th row and the j’th column to value. Assumes that the indices i and j are legal, i.e 0

Parameters:

value - value you want inserted in

i - row i

j - col j

getRowNum

public int getRowNum()

Returns the number of rows in the matrix.

Returns:

int the number of rows in matrix

getColNum

public int getColNum()

Returns the number of columns in the matrix.

Returns:

int the number of cols in matrix

getRowVector

public AlgebraicVector getRowVector(int i)

Returns the i'th row in the matrix as an AlgebraicVector object. Assumes i is legal.

Parameters:

i - the row in the matrix you want back as vector

Returns:

AlgebraicVector the row i as AlgebraicVector

getColVector

public AlgebraicVector getColVector(int i)

Returns the i'th column in the matrix as an AlgebraicVector object. Assumes i is legal.

Parameters:

i - the col in the matrix you want back as vector

Returns:

AlgebraicVector the col i as AlgebraicVector

getRowsAsVectors

public AlgebraicVector[] getRowsAsVectors()

Returns the rows of the matrix as an array of AlgebraicVectors

Returns:

AlgebraicVector[] an Array of vectors with all the matrix

add

public Matrix add(Matrix other)

Adds the other matrix to the current matrix and returns the result in a new Matrix object. Assumes that the other Matrix has the same dimensions as the current matrix.

Parameters:

other - the matrix you want tho add

Returns:

matrix the sum of the 2 matrices

sub

public Matrix sub(Matrix other)

Substracts the other matrix to the current matrix and returns the result in a new Matrix object. Assumes that the other Matrix has the same dimensions as the current matrix.

Parameters:

other - the matrix you want tho substract

Returns:

matrix the substraction of the 2 matrices

mul

public Matrix mul(Matrix other)

Multiplies the other matrix to the current matrix and returns the result in a new Matrix object. Assumes that the other Matrix’s number of rows equals the current matrixe’s number of columns.

Parameters:

other - the matrix you want to multiply

Returns:

matrix the multiplication of the 2 matrices

mul

public Matrix mul(double scalar)

Computes the multiplication of the current matrix with the given scalar. Returns the result in a new Matrix object.

Parameters:

scalar - a scalar you want to multiply

Returns:

matrix the multiplication of the matrix with the scalar

mul

public AlgebraicVector mul(AlgebraicVector other)

Computes the multiplication of the current matrix with the given vector. Returns the result in a new AlgebraicVector object. Assumes the the dimension of other equals the number of columns in the current matrix.

Parameters:

other - a vector you want to multiply

Returns:

AlgebraicVector mult. of the matrix with vector

setRowVector

public void setRowVector(AlgebraicVector vec,
                         int i)

Replace row i in the matrix with the given vector Assumes dimension of vector equal to the number of cols

Parameters:

vec - AlgebraicVector containing the vector to set

i - The row number to replace with the given vector

swapRows

private void swapRows(int i,
                      int j)

Swaps between 2 rows in the matrix.

Parameters:

i - row i

j - row j

gaussElimination

public AlgebraicVector gaussElimination()

Retruns a vector that is the solution of the set of equations defined by this augmented matrix. If the equations are not solvable returns null.

Returns:

AlgebraicVector vector with the solution to the matrix if possible (null if no solution)

toString

public java.lang.String toString()

Returns a string representation of the vector in the following format: 2.0 3.1 5.4

Overrides:

toString in class java.lang.Object