im_inv(1)

NAME
im_inv - inverse image

CALLING SEQUENCE
[X,dim]=im_inv(A,B [,tol])

PARAMETERS

A,B : two real or complex matrices with equal number of columns

X   : orthogonal or unitary square matrix of order equal to the number of columns of A

dim : integer (dimension of subspace)

DESCRIPTION
computes
(A^-1)(B)
 i.e vectors whose image through A are in range(B)

The dim first columns of X span
(A^-1) (B)

tol is a threshold used to test if subspace inclusion;
default value is tol = 100*%eps.

SEE ALSO
rowcomp

AUTHOR
F. D.