Class DenseSparseMatrix

java.lang.Object

org.tribuo.math.la.DenseSparseMatrix

All Implemented Interfaces:

Serializable, Iterable<MatrixTuple>, Matrix, Tensor

public class DenseSparseMatrix
extends Object
implements Matrix

A matrix which is dense in the first dimension and sparse in the second.

Backed by an array of SparseVector.

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
DenseSparseMatrix(List<SparseVector> values)
DenseSparseMatrix(DenseSparseMatrix other)

Method Summary

Modifier and Type	Method	Description
void	add(int i, int j, double value)	Adds the argument value to the value at the supplied index.
static DenseSparseMatrix	createFromSparseVectors(SparseVector[] values)	Defensively copies the values.
boolean	equals(Object other)
void	foreachInPlace(DoubleUnaryOperator f)	Applies a DoubleUnaryOperator elementwise to this Tensor.
double	get(int i, int j)	Gets an element from this Matrix.
int	getDimension1Size()	The size of the first dimension.
int	getDimension2Size()	The size of the second dimension.
SparseVector	getRow(int i)	Extract a row as an SGDVector.
int[]	getShape()	Returns an int array specifying the shape of this Tensor.
void	hadamardProductInPlace(Tensor other, DoubleUnaryOperator f)	Only implemented for DenseMatrix.
int	hashCode()
void	intersectAndAddInPlace(Tensor other, DoubleUnaryOperator f)	Only implemented for DenseMatrix.
MatrixIterator	iterator()
DenseVector	leftMultiply(SGDVector input)	Multiplies this Matrix by a SGDVector returning a vector of the appropriate size.
DenseMatrix	matrixMultiply(Matrix other)	Multiplies this Matrix by another Matrix returning a matrix of the appropriate size.
DenseMatrix	matrixMultiply(Matrix other, boolean transposeThis, boolean transposeOther)	Multiplies this Matrix by another Matrix returning a matrix of the appropriate size.
int	numActiveElements(int row)	The number of non-zero elements in that row.
Tensor	reshape(int[] newShape)	Reshapes the Tensor to the supplied shape.
DenseVector	rightMultiply(SGDVector input)	rightMultiply is very inefficient on DenseSparseMatrix due to the storage format.
void	rowScaleInPlace(DenseVector scalingCoefficients)	Scales each row by the appropriate value in the DenseVector.
DenseVector	rowSum()	Generates a DenseVector representing the sum of each row.
void	set(int i, int j, double value)	Sets an element at the supplied location.
String	toString()
double	twoNorm()	Calculates the euclidean norm for this vector.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Methods inherited from interface org.tribuo.math.la.Tensor

hadamardProductInPlace, intersectAndAddInPlace, scalarAddInPlace, scaleInPlace

Constructor Details

DenseSparseMatrix

public DenseSparseMatrix(List<SparseVector> values)

DenseSparseMatrix

public DenseSparseMatrix(DenseSparseMatrix other)

Method Details

createFromSparseVectors

public static DenseSparseMatrix createFromSparseVectors(SparseVector[] values)

Defensively copies the values.

Parameters:

values - The sparse vectors to use.

Returns:

A DenseSparseMatrix containing the supplied vectors.

getShape

public int[] getShape()

Description copied from interface: Tensor

Returns an int array specifying the shape of this Tensor.

Specified by:

getShape in interface Tensor

Returns:

An int array.

reshape

public Tensor reshape(int[] newShape)

Description copied from interface: Tensor

Reshapes the Tensor to the supplied shape. Throws IllegalArgumentException if the shape isn't compatible.

Specified by:

reshape in interface Tensor

Parameters:

newShape - The desired shape.

Returns:

A Tensor of the desired shape.

get

public double get(int i,
 int j)

Description copied from interface: Matrix

Gets an element from this Matrix.

Specified by:

get in interface Matrix

Parameters:

i - The index for the first dimension.

j - The index for the second dimension.

Returns:

The value at matrix[i][j].

set

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

Description copied from interface: Matrix

Sets an element at the supplied location.

Specified by:

set in interface Matrix

Parameters:

i - The index for the first dimension.

j - The index for the second dimension.

value - The value to be stored at matrix[i][j].

getDimension1Size

public int getDimension1Size()

Description copied from interface: Matrix

The size of the first dimension.

Specified by:

getDimension1Size in interface Matrix

Returns:

The size of the first dimension.

getDimension2Size

public int getDimension2Size()

Description copied from interface: Matrix

The size of the second dimension.

Specified by:

getDimension2Size in interface Matrix

Returns:

The size of the second dimension.

leftMultiply

public DenseVector leftMultiply(SGDVector input)

Description copied from interface: Matrix

Multiplies this Matrix by a SGDVector returning a vector of the appropriate size.

The input must have dimension equal to Matrix.getDimension2Size().

Specified by:

leftMultiply in interface Matrix

Parameters:

input - The input vector.

Returns:

A new SGDVector of size Matrix.getDimension1Size().

rightMultiply

public DenseVector rightMultiply(SGDVector input)

rightMultiply is very inefficient on DenseSparseMatrix due to the storage format.

Specified by:

rightMultiply in interface Matrix

Parameters:

input - The input vector.

Returns:

A*input.

add

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

Description copied from interface: Matrix

Adds the argument value to the value at the supplied index.

Specified by:

add in interface Matrix

Parameters:

i - The index for the first dimension.

j - The index for the second dimension.

value - The value to add.

intersectAndAddInPlace

public void intersectAndAddInPlace(Tensor other,
 DoubleUnaryOperator f)

Only implemented for DenseMatrix.

Specified by:

intersectAndAddInPlace in interface Tensor

Parameters:

other - The other Tensor.

f - A function to apply.

hadamardProductInPlace

public void hadamardProductInPlace(Tensor other,
 DoubleUnaryOperator f)

Only implemented for DenseMatrix.

Specified by:

hadamardProductInPlace in interface Tensor

Parameters:

other - The other Tensor.

f - A function to apply.

foreachInPlace

public void foreachInPlace(DoubleUnaryOperator f)

Description copied from interface: Tensor

Applies a DoubleUnaryOperator elementwise to this Tensor.

Specified by:

foreachInPlace in interface Tensor

Parameters:

f - The function to apply.

numActiveElements

public int numActiveElements(int row)

Description copied from interface: Matrix

The number of non-zero elements in that row.

An element could be active and zero, if it was active on construction.

Specified by:

numActiveElements in interface Matrix

Parameters:

row - The index of the row.

Returns:

The number of non-zero elements.

getRow

public SparseVector getRow(int i)

Description copied from interface: Matrix

Extract a row as an SGDVector.

This refers to the same values as the matrix, so updating this vector will update the matrix.

Specified by:

getRow in interface Matrix

Parameters:

i - The index of the row to extract.

Returns:

An SGDVector.

equals

public boolean equals(Object other)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

twoNorm

public double twoNorm()

Description copied from interface: Tensor

Calculates the euclidean norm for this vector.

Specified by:

twoNorm in interface Tensor

Returns:

The euclidean norm.

matrixMultiply

public DenseMatrix matrixMultiply(Matrix other)

Description copied from interface: Matrix

Multiplies this Matrix by another Matrix returning a matrix of the appropriate size.

The input must have dimension 1 equal to Matrix.getDimension2Size().

Specified by:

matrixMultiply in interface Matrix

Parameters:

other - The input matrix.

Returns:

A new Matrix of size Matrix.getDimension1Size(), input.getDimension2Size().

matrixMultiply

public DenseMatrix matrixMultiply(Matrix other,
 boolean transposeThis,
 boolean transposeOther)

Description copied from interface: Matrix

Multiplies this Matrix by another Matrix returning a matrix of the appropriate size.

Must obey the rules of matrix multiplication after the transposes are applied.

Specified by:

matrixMultiply in interface Matrix

Parameters:

other - The input matrix.

transposeThis - Implicitly transposes this matrix just for the multiplication.

transposeOther - Implicitly transposes other just for the multiplication.

Returns:

A new Matrix.

rowSum

public DenseVector rowSum()

Description copied from interface: Matrix

Generates a DenseVector representing the sum of each row.

Specified by:

rowSum in interface Matrix

Returns:

A new DenseVector of size Matrix.getDimension1Size().

rowScaleInPlace

public void rowScaleInPlace(DenseVector scalingCoefficients)

Description copied from interface: Matrix

Scales each row by the appropriate value in the DenseVector.

Specified by:

rowScaleInPlace in interface Matrix

Parameters:

scalingCoefficients - A DenseVector with size Matrix.getDimension1Size().

toString

public String toString()

Overrides:

toString in class Object

iterator

public MatrixIterator iterator()

Specified by:

iterator in interface Iterable<MatrixTuple>