shh.csparse
Class Matrix

Object
  Matrix

Direct Known Subclasses:

CSparse, DenseMatrixZ, ElemMatrix

public abstract class Matrix

extends Object

A general interface for m × n matrices.

The interface specifies whether operations are destructive--whether they alter this matrix or any of their arguments. Consult the individual implementations for whether a method is supported, whether it checks for errors in its arguments, or whether null can be a return value.

Vectors are thought of as column vectors throughout. If the vector space V has dimension n and W has dimension m, then a map V → W is represented by an m × n matrix A. If x is an n-dimensional column vector giving a point of V with respect to standard coordinates, then the coordinates of its image are given by the m-dimensional column vector Ax.

Author:

Mark McConnell

Constructor Summary

Matrix()

Method Summary

abstract Matrix	add(Matrix b) The sum of two matrices.
abstract SparseElt	get(int i, int j) Returns a SparseElt whose value is the i,j value of the matrix.
abstract int	getNumCols() Returns the number n of columns.
abstract int	getNumRows() Returns the number m of rows.
abstract Matrix	inverse() Check the implementation for whether it's supported, and whether it's destructive.
abstract boolean	isIdentity() Whether this is an n × n identity matrix.
abstract boolean	isProductZero(Matrix b) Says whether this * b is zero, without storing the product.
abstract boolean	isZero() Whether every entry in this matrix is zero.
abstract Matrix	mult(Matrix b) Returns this * b.
abstract void	set(SparseElt rowIndexAndVal, int colIndex) Check the implementation for whether it throws an UnsupportedOperationException.
String	toString() Formats the matrix with each column left-justified.
abstract Matrix	transpose() Non-destructive.

Methods inherited from class Object

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

Constructor Detail

Matrix

public Matrix()

Method Detail

add

public abstract Matrix add(Matrix b)

The sum of two matrices. Non-destructive.

Throws:

IllegalArgumentException - If the dimensions don't match.

get

public abstract SparseElt get(int i,
                              int j)

Returns a SparseElt whose value is the i,j value of the matrix. May return null for a zero entry. The index of the SparseElt is unspecified--there is no guarantee it is either i or j.

getNumCols

public abstract int getNumCols()

Returns the number n of columns.

getNumRows

public abstract int getNumRows()

Returns the number m of rows.

inverse

public abstract Matrix inverse()

Check the implementation for whether it's supported, and whether it's destructive.

isIdentity

public abstract boolean isIdentity()

Whether this is an n × n identity matrix.

isProductZero

public abstract boolean isProductZero(Matrix b)

Says whether this * b is zero, without storing the product. Is not destructive.

isZero

public abstract boolean isZero()

Whether every entry in this matrix is zero.

mult

public abstract Matrix mult(Matrix b)

Returns this * b. Check the implementation for whether it's destructive.

Throws:

UnsupportedOperationException - If there is no implementation for multiplying the class of this by the class of b.

IllegalArgumentException - The implementation may (or may not) throw this if the inner dimensions don't match.

set

public abstract void set(SparseElt rowIndexAndVal,
                         int colIndex)

Check the implementation for whether it throws an UnsupportedOperationException.

toString

public String toString()

Formats the matrix with each column left-justified.

transpose

public abstract Matrix transpose()

Non-destructive.