FUNCTION: Perm2Mat - calculate the permutation matrix

CALLING SEQUENCE:

Perm2Mat(perm)

SG[Perm2Mat](perm)

PARAMETERS:

perm = any list denoting a permutation

SYNOPSIS:

• The Perm2Mat function calculates the permutation matrix corresponding to perm. This matrix has entries 1 in position (i, perm[i]) and 0 otherwise.

• Whenever there is a conflict between the function name Perm2Mat and another name used in the same session, use the long form SG['Perm2Mat'].

EXAMPLES:

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