Function: vecmin
Section: operators
C-Name: vecmin0
Prototype: GD&
Help: vecmin(x,{&v}): smallest entry in the vector/matrix x. If v is
 present, set it to the index of a smallest
 entry (indirect min).
Description:
  (gen):gen            vecmin($1)
  (gen, &gen):gen      vecmin0($1, &$2)
Doc: if $x$ is a vector or a matrix, returns the smallest entry of $x$,
 otherwise returns a copy of $x$. Error if $x$ is empty.

 If $v$ is given, set it to the index of a smallest entry (indirect minimum),
 when $x$ is a vector. If $x$ is a matrix, set $v$ to coordinates $[i,j]$ such
 that $x[i,j]$ is a smallest entry. This is ignored if $x$ is not a vector or
 matrix.

 \bprog
 ? vecmin([10, 20, -30, 40])
 %1 = -30
 ? vecmin([10, 20, -30, 40], &v); v
 %2 = 3
 ? vecmin([10, 20; -30, 40], &v); v
 %3 = [2, 1]
 @eprog

Variant: When $v$ is not needed, the function \fun{GEN}{vecmin}{GEN x} is also
 available.
