8.6.2. MDOMatrix

MDOMatrix

Represents a matrix class with a double value. Typically used to interact with matrix attributes.

Methods

coo	Construct a sparse matrix with indexes and values
coo	Construct a sparse matrix containing row indexes, column indexes, and values
csc	Construct a matrix in the format of compressed sparse columns (CSC)
csr	Construct a compressed sparse row (CSR) formatting matrix
dense	Construct a dense matrix
full	Construct a matrix whose internal elements are all value
identity	Construct a square matrix where the main diagonal elements are all 1
zero	Construct a matrix containing only zeros
cols	The number of columns contained in this matrix
data	Retrieve the ith value in this matrix
index	Retrieve the index of the ith non-zero element in this matrix
nzs	The number of non-zero elements in a matrix
rows	The number of rows contained in this matrix
toString	Convert the current matrix into String format

static MDOMatrix coo(int rows, int cols, int[] indices, double[] data)

Construct a sparse matrix with indexes and values.

Parameters

• int rows – The number of rows.

• int cols – The number of columns.

• int[] indices – Indexes of all non-zero elements.

• double[] data – Values of all non-zero elements.

Returns

Newly created matrix.

static MDOMatrix coo(int rows, int cols, int[] rowIndices, int[] colIndices, double[] data)

Construct a sparse matrix containing row indexes, column indexes, and values.

Parameters

• int rows – The Number of rows.

• int cols – The Number of columns.

• int[] rowIndices – Row indexes of all non-zero elements.

• int[] colIndices – Column indexes of all non-zero elements.

• double[] data – Values of all non-zero elements.

Returns

Newly created matrix.

static MDOMatrix csc(int rows, int cols, int[] ptr, int[] ind, double[] data)

Construct a matrix in the format of compressed sparse columns (CSC).

Parameters

• int rows – The number of rows.

• int cols – The number of columns.

• int[] ptr – The begin indices in ind of columns contained in matrix.

• int[] ind – Row indices of all non-zero elements.

• double[] data – Values of all non-zero elements.

Returns

Newly created matrix.

static MDOMatrix csr(int rows, int cols, int[] ptr, int[] ind, double[] data)

Construct a compressed sparse row (CSR) formatting matrix.

Parameters

• int rows – The number of rows.

• int cols – The number of columns.

• int[] ptr – The begin indices in ind of rows contained in matrix.

• int[] ind – Column indices of all non-zero elements.

• double[] data – Values of all non-zero elements.

Returns

Newly created matrix.

static MDOMatrix dense(int rows, int cols, double[] data)

Construct a dense matrix.

Parameters

• int rows – The number of rows.

• int cols – The number of columns.

• double[] data – Values for all elements. It should have at least rows * cols elements.

Returns

The newly created matrix.

static MDOMatrix full(int rows, int cols, double value)

Construct a matrix whose internal elements are all value .

Parameters

• int rows – The number of rows.

• int cols – The number of columns.

• double value – The value of all matrix elements.

Returns

The newly created matrix.

static MDOMatrix identity(int n)

Construct a square matrix where the main diagonal elements are all 1.

Parameters

int n – The dimension of the new matrix, that is, the number of rows and columns of the square matrix.

Returns

The newly created matrix.

static MDOMatrix zero(int rows, int cols)

Construct a matrix containing only zeros.

Parameters

• int rows – Number of rows.

• int cols – Number of columns.

Returns

The newly created matrix.

int cols()

The number of columns contained in this matrix.

Returns

The number of columns contained in this matrix.

double data(int i)

Retrieve the ith value in this matrix.

Parameters

int i – Index i to query

Returns

The ith value in this matrix.

int index(int i)

Retrieve the index of the ith non-zero element in this matrix.

Parameters

int i – The position of this non-zero element in the matrix.

Returns

The index position of the ith non-zero element in this matrix.

int nzs()

The number of non-zero elements in a matrix.

Returns

The number of non-zero elements in a matrix.

int rows()

The number of rows contained in this matrix.

Returns

The number of rows contained in this matrix.

String toString()

Convert the current matrix into String format.

Returns

The string format of the matrix.