no.uib.cipr.matrix

Class PermutationMatrix

java.lang.Object

no.uib.cipr.matrix.AbstractMatrix

no.uib.cipr.matrix.PermutationMatrix

All Implemented Interfaces:

Iterable<MatrixEntry>, Matrix

public class PermutationMatrix
extends AbstractMatrix

Matrix that represents a permutation of another matrix's rows / columns.

NOTE: the transpose of a permutation matrix is its inverse.

Author:

Sam Halliday

Nested Class Summary

Nested classes/interfaces inherited from interface no.uib.cipr.matrix.Matrix

Matrix.Norm

Field Summary

Fields inherited from class no.uib.cipr.matrix.AbstractMatrix

numColumns, numRows

Constructor Summary

Constructors

Constructor and Description
PermutationMatrix(int[] permutations)

Method Summary

Modifier and Type	Method and Description
static PermutationMatrix	fromPartialPivots(int[] pivots) The sequential row permutations to perform, e.g.
double	get(int row, int column) Returns A(row,column)
Matrix	mult(Matrix B, DenseMatrix C)
Matrix	mult(Matrix B, Matrix C) C = A*B
Matrix	transAmult(Matrix B, DenseMatrix C)
Matrix	transAmult(Matrix B, Matrix C) C = AT*B
Matrix	transpose() Transposes the matrix in-place.

Methods inherited from class no.uib.cipr.matrix.AbstractMatrix

add, add, add, check, checkMultAdd, checkMultAdd, checkRank1, checkRank1, checkRank2, checkRank2, checkSize, checkSolve, checkSolve, checkTransABmultAdd, checkTransAmultAdd, checkTransBmultAdd, checkTransMultAdd, checkTranspose, checkTranspose, checkTransRank1, checkTransRank2, copy, isSquare, iterator, max, max, mult, mult, mult, multAdd, multAdd, multAdd, multAdd, norm, norm1, normF, normInf, numColumns, numRows, rank1, rank1, rank1, rank1, rank1, rank1, rank2, rank2, rank2, rank2, scale, set, set, set, solve, solve, toString, transABmult, transABmult, transABmultAdd, transABmultAdd, transAmult, transAmultAdd, transAmultAdd, transBmult, transBmult, transBmultAdd, transBmultAdd, transMult, transMult, transMultAdd, transMultAdd, transpose, transRank1, transRank1, transRank2, transRank2, transSolve, transSolve, zero

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

PermutationMatrix

public PermutationMatrix(int[] permutations)

Method Detail

fromPartialPivots

public static PermutationMatrix fromPartialPivots(int[] pivots)

The sequential row permutations to perform, e.g. (2, 3, 3) means: permute row 1 with row 2, then permute row 2 with row 3, then permute row 3 with row 3 (i.e. do nothing).

Using this factory will ensure that LAPACK optimisations are available for multiplication operations.

Parameters:

pivots - using fortran (1-indexed) notation.

get

public double get(int row,
                  int column)

Description copied from interface: Matrix

Returns A(row,column)

Specified by:

get in interface Matrix

Overrides:

get in class AbstractMatrix

transpose

public Matrix transpose()

Description copied from interface: Matrix

Transposes the matrix in-place. In most cases, the matrix must be square for this to work.

Specified by:

transpose in interface Matrix

Overrides:

transpose in class AbstractMatrix

Returns:

This matrix

mult

public Matrix mult(Matrix B,
                   Matrix C)

Description copied from interface: Matrix

C = A*B

Specified by:

mult in interface Matrix

Overrides:

mult in class AbstractMatrix

Parameters:

B - Matrix such that B.numRows() == A.numColumns() and B.numColumns() == C.numColumns()

C - Matrix such that C.numRows() == A.numRows() and B.numColumns() == C.numColumns()

Returns:

C

mult

public Matrix mult(Matrix B,
                   DenseMatrix C)

transAmult

public Matrix transAmult(Matrix B,
                         Matrix C)

Description copied from interface: Matrix

C = AT*B

Specified by:

transAmult in interface Matrix

Overrides:

transAmult in class AbstractMatrix

Parameters:

B - Matrix such that B.numRows() == A.numRows() and B.numColumns() == C.numColumns()

C - Matrix such that C.numRows() == A.numColumns() and B.numColumns() == C.numColumns()

Returns:

C

transAmult

public Matrix transAmult(Matrix B,
                         DenseMatrix C)