function s = sum (x, dim) if (nargin < 1 || nargin > 2) print_usage ("sum"); endif if (nargin == 1) s = builtin ("sum", x); else if (! isnumeric (dim) || ! isvector (dim)) error ("sum: DIM must be a numeric scalar or vector"); endif s = builtin ("sum", x, dim(1)); for i = 2:numel (dim) s = builtin ("sum", s, dim(i)); endfor endif endfunction