% Extract the elements of x of size l from the center, the right or the left.
SYNOPSIS
function y = wkeep(x,l,opt)
DESCRIPTION
% -*- texinfo -*-
% @deftypefn {Function File} {[@var{y}] =} wkeep(@var{x,l,opt})
% Extract the elements of x of size l from the center, the right or the left.
% @end deftypefn