FUNCTION: Mat2Perm - calculate a permutation from its matrix of permutation

CALLING SEQUENCE:

Mat2Perm(sqm)

SG[Mat2Perm](sqm)

PARAMETERS:

sqm = any square permutation matrix

SYNOPSIS:

• The Mat2Perm function calculates a permutation from a matrix. Given a permutation perm, the corresponding matrix has entries 1 in position (i, perm[i]) and 0 otherwise.

• Whenever there is a conflict between the function name Mat2Perm and another name used in the same session, use the long form SG['Mat2Perm'].

EXAMPLES:

> with(SG):
> Perm2Mat([2,4,3,1]);
 
                               [ 0  1  0  0 ]
                               [            ]
                               [ 0  0  0  1 ]
                               [            ]
                               [ 0  0  1  0 ]
                               [            ]
                               [ 1  0  0  0 ]
 
> Mat2Perm( Perm2Mat([2,4,3,1]) );
 
                                [2, 4, 3, 1]