Function: matimage
Section: linear_algebra
C-Name: matimage0
Prototype: GD0,L,
Help: matimage(x,{flag=0}): basis of the image of the matrix x. flag is
 optional and can be set to 0 or 1, corresponding to two different algorithms.
Description:
 (gen, ?0):vec           image($1)
 (gen, 1):vec            image2($1)
 (gen, #small)           $"incorrect flag in matimage"
 (gen, small):vec        matimage0($1, $2)
Doc: gives a basis for the image of the
 matrix $x$ as columns of a matrix. A priori the matrix can have entries of
 any type. If $\fl=0$, use standard Gauss pivot. If $\fl=1$, use
 \kbd{matsupplement} (much slower: keep the default flag!).

Variant: Also available is \fun{GEN}{image}{GEN x} ($\fl=0$).
