% adct - arrow for DCT
%
% adct :: M:natural -> arrow({[[N]]}, {[[M]]}, empty).
%
% Produces only the first M DCT coefficients
function o=adct(M)
	I=1:M;
	o=arrf(@mkdct,1,1);

	function f=mkdct(sizes_in)
		% take DCT size from size(1) of first input
		%W=row(dct(eye(sizes_in{1}(1))),M);
		f=@(x)row(dct(x),I);
	end
end

