function x=dd(x)
% dd - convert input sequence or array to sequence
%
% dd :: [[N,M]] -> seq([[N]]).
% dd :: [[N]] -> seq(real).
% dd :: seq([[N,M]]) -> seq([[N]]).

if isseq(x)
	if size(x,2)>1, x=concat(map(@slices,x)); end
else
	if isscalar(x),     x=repeat(x); 
	else                x=slices(x);
	end
end
