function y=denoise(x,n,p)
%  DENOISE
% y = denoise(x,n,p) performs the following on the data stored in 
% columns of x:
%       1) n-time differentiation
%       2) p-point smoothing
%       3) n-time integration
%  the result os of same length as x for convenience.
%  For notes on possible zero-padding artifacts, see SMOOTH and NDIFF.

[yd,c] = ndiff(x,n);

f=mean(yd);
ys = smooth(yd,p);
yi=ys-mean(ys) + f;

for m=1:n,
   yi=cumsum(yi);
   yi=yi-mean(yi)+c(n+1-m,:);
end

y=yi;