com.github.signaflo.math.linear.doubles

Interface Matrix

public interface Matrix

A real-valued matrix.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	Matrix.Layout Specifies the layout of the two-dimensional array representation of a matrix.

Method Summary

Modifier and Type	Method and Description
static MatrixBuilder	builder(int m, int n) Create a new builder for an m by n matrix with all elements initially set to zero.
static Matrix	create(double[]... matrixData) Create a new matrix from the given two-dimensional array of data, assuming that the data is laid out by row.
static Matrix	create(int nrow, int ncol, double... data) Create a new matrix with the supplied data and dimensions.
static Matrix	create(Matrix.Layout layout, double[]... matrixData) Create a new matrix from the given two-dimensional array of data.
double[]	data() Obtain the array of data underlying this matrix in row-major order.
double[][]	data2D() Obtain the data in this matrix as a two-dimensional array.
double[][]	data2D(Matrix.Layout layout) Obtain the data in this matrix as a two-dimensional array.
double[]	diagonal() Retrieve the elements on the diagonal of this matrix.
static Matrix	fill(int nrow, int ncol, double value) Create a new matrix with the given dimensions filled with the supplied value.
double	get(int i, int j) Get the element at row i, column j.
Vector	getColumn(int j) Get the jth column of the matrix.
Vector	getRow(int i) Get the ith row of the matrix.
static Matrix	identity(int n) Create a new identity matrix with the given dimension.
static MatrixBuilder	identityBuilder(int n) Create a new builder for a square matrix of size n with ones on the diagonal.
boolean	isSquare() Returns true if the matrix is square and false otherwise.
Matrix	minus(Matrix other) Subtract the given matrix from this matrix and return the resulting difference.
int	ncol() Retrieve the number of columns of this matrix.
int	nrow() Retrieve the number of rows of this matrix.
Matrix	plus(Matrix other) Add this matrix to the given matrix and return the resulting sum.
Matrix	pushColumn(Vector newData) Push the provided vector to the front of this matrix, shifting all other vectors to the right.
Matrix	pushRow(Vector newData) Push the provided vector to the top of this matrix, shifting all other vectors down.
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.
Matrix	transpose() Transpose this matrix and return the resulting transposition.

Method Detail

create

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.

Throws:

IllegalArgumentException - if the length of the data array does not equal the given number of rows multiplied by the given number of columns.

fill

static Matrix fill(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.

Returns:

a new matrix with the given dimensions filled with the provided value.

create

static Matrix create(double[]... matrixData)

Create a new matrix from the given two-dimensional array of data, assuming that the data is laid out by row. If the data is instead laid out by column, then specify that by supplying Matrix.Layout.BY_COLUMN as the second argument to this method.

Parameters:

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

Returns:

a new matrix with the given data.

create

static Matrix create(Matrix.Layout layout,
                     double[]... matrixData)

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

Parameters:

layout - the layout of the elements in the matrix data.

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

Returns:

a new matrix with the given data and layout.

identity

static Matrix identity(int n)

Create a new identity matrix with the given dimension.

Parameters:

n - the dimension of the identity matrix.

Returns:

a new identity matrix with the given dimension.

get

double get(int i,
           int j)

Get the element at row i, column j.

Parameters:

i - the element's row location.

j - the element's column location.

Returns:

the element at row i, column j.

nrow

int nrow()

Retrieve the number of rows of this matrix.

Returns:

the number of rows of this matrix.

ncol

int ncol()

Retrieve the number of columns of this matrix.

Returns:

the number of columns of this matrix.

plus

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.

Throws:

IllegalArgumentException - if the dimensions of this matrix do not match the dimensions of the given matrix.

times

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.

Throws:

IllegalArgumentException - if the number of columns of this matrix does not equal the number of rows of the given matrix.

times

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.

Throws:

IllegalArgumentException - if the number of columns of this matrix does not equal the size of the given vector.

scaledBy

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

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.

Throws:

IllegalArgumentException - if the dimensions of this matrix do not match the dimensions of the given matrix.

isSquare

boolean isSquare()

Returns true if the matrix is square and false otherwise.

Returns:

true if the matrix is square and false otherwise.

transpose

Matrix transpose()

Transpose this matrix and return the resulting transposition.

Returns:

the transpose of this matrix.

getRow

Vector getRow(int i)

Get the ith row of the matrix.

Parameters:

i - the row index, where indexing begins at 0.

Returns:

the ith row of the matrix.

getColumn

Vector getColumn(int j)

Get the jth column of the matrix.

Parameters:

j - the column index, where indexing begins at 0.

Returns:

the jth column of the matrix.

pushRow

Matrix pushRow(Vector newData)

Push the provided vector to the top of this matrix, shifting all other vectors down.

Parameters:

newData - the new vector of data.

Returns:

a matrix with the given vector pushed to the top of this matrix.

Throws:

IllegalArgumentException - if size of the given vector does not equal the number of columns of this matrix.

pushColumn

Matrix pushColumn(Vector newData)

Push the provided vector to the front of this matrix, shifting all other vectors to the right.

Parameters:

newData - the new vector of data.

Returns:

a matrix with the given vector pushed to the front of this matrix.

Throws:

IllegalArgumentException - if size of the given vector does not equal the number of rows of this matrix.

diagonal

double[] diagonal()

Retrieve the elements on the diagonal of this matrix.

Returns:

the elements on the diagonal of this matrix.

data

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

double[][] data2D(Matrix.Layout layout)

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

Parameters:

layout - the layout of the elements in the matrix data.

Returns:

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

data2D

double[][] data2D()

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

Returns:

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

identityBuilder

static MatrixBuilder identityBuilder(int n)

Create a new builder for a square matrix of size n with ones on the diagonal.

Parameters:

n - the dimension of the matrix.

Returns:

a new builder for a square matrix of size n with ones on the diagonal.

builder

static MatrixBuilder builder(int m,
                             int n)

Create a new builder for an m by n matrix with all elements initially set to zero.

Parameters:

m - the number of columns of the matrix.

n - the the number of columns of the matrix.

Returns:

a new builder with all elements initially set to zero.