math.linear.doubles

Class Matrix

java.lang.Object

math.linear.doubles.Matrix

public final class Matrix
extends Object

An immutable and thread-safe implementation of a real-valued matrix.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Matrix.IdentityBuilder A class that allows one to start with an identity matrix, then set specific elements before creating an immutable Matrix.
static class	Matrix.Order

Constructor Summary

Constructors

Constructor and Description
Matrix(double[][] matrixData, Matrix.Order order) Create a new matrix from the given two-dimensional array of data.
Matrix(int nrow, int ncol, double value) Create a new matrix with the given dimensions filled with the supplied value.

Method Summary

Modifier and Type	Method and Description
static Matrix	create(int nrow, int ncol, double[] data) Create a new matrix with the supplied data and dimensions.
double[]	data() Obtain the array of data underlying this matrix in row-major order.
double[][]	data2D(Matrix.Order order) Obtain the data in this matrix as a two-dimensional array.
double[]	diagonal() Retrieve the elements on the diagonal of this matrix.
boolean	equals(Object o)
int	hashCode()
Matrix	minus(Matrix other) Subtract the given matrix from this matrix and return the resulting difference.
int	ncol()
int	nrow()
Matrix	plus(Matrix other) Add this matrix to the given matrix and return the resulting sum.
Matrix	scaledBy(double c) Scale this matrix by the given value and return the scaled matrix.
Matrix	times(Matrix other) Multiply this matrix by the given matrix and return the resulting product.
Vector	times(Vector vector) Multiply this matrix by the given vector and return the resulting transformation.
String	toString()
Matrix	transpose() Transpose this matrix and return the resulting transposition.

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Matrix

public Matrix(int nrow,
              int ncol,
              double value)

Create a new matrix with the given dimensions filled with the supplied value.

Parameters:

nrow - the number of rows for the matrix.

ncol - the number of columns for the matrix.

value - the data point to fill the matrix with.

Matrix

public Matrix(double[][] matrixData,
              Matrix.Order order)

Create a new matrix from the given two-dimensional array of data.

Parameters:

matrixData - the two-dimensional array of data constituting the matrix.

order - the storage order of the elements in the matrix data.

Method Detail

nrow

public int nrow()

ncol

public int ncol()

create

public static Matrix create(int nrow,
                            int ncol,
                            double[] data)

Create a new matrix with the supplied data and dimensions. The data is assumed to be in row-major order.

Parameters:

nrow - the number of rows for the matrix.

ncol - the number of columns for the matrix.

data - the data in row-major order.

Returns:

a new matrix with the supplied data and dimensions.

plus

public Matrix plus(Matrix other)

Add this matrix to the given matrix and return the resulting sum.

Parameters:

other - the matrix to add to this one.

Returns:

this matrix added to the other matrix.

times

public Matrix times(Matrix other)

Multiply this matrix by the given matrix and return the resulting product.

Parameters:

other - the matrix to multiply by.

Returns:

the product of this matrix with the given matrix.

times

public Vector times(Vector vector)

Multiply this matrix by the given vector and return the resulting transformation.

Parameters:

vector - the vector to multiply.

Returns:

the given vector multiplied by this matrix.

scaledBy

public Matrix scaledBy(double c)

Scale this matrix by the given value and return the scaled matrix.

Parameters:

c - the value to scale this matrix by.

Returns:

this matrix scaled by the given value.

minus

public Matrix minus(Matrix other)

Subtract the given matrix from this matrix and return the resulting difference.

Parameters:

other - the matrix to subtract from this one.

Returns:

the difference of this matrix and the given matrix.

transpose

public Matrix transpose()

Transpose this matrix and return the resulting transposition.

Returns:

the transpose of this matrix.

diagonal

public double[] diagonal()

Retrieve the elements on the diagonal of this matrix.

Returns:

the elements on the diagonal of this matrix.

data

public double[] data()

Obtain the array of data underlying this matrix in row-major order.

Returns:

the array of data underlying this matrix in row-major order.

data2D

public double[][] data2D(Matrix.Order order)

Obtain the data in this matrix as a two-dimensional array.

Parameters:

order - the storage order of the elements in the matrix data.

Returns:

the data in this matrix as a two-dimensional array.

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object