dawn@0: % rsum_inplace(x,N) - in place running sum
dawn@0: %
dawn@0: %  x: matrix to sum
dawn@0: %  N: samples - size of running sum window
dawn@0: %
dawn@0: % Matrix x is summed row-wise.  The last (N-1) samples are not valid.
dawn@0: % N may be fractionary (handled by linear interpolation).
dawn@0: % 
dawn@0: % Mex function.  
dawn@0: % Beware: input argument is assigned to.  This is not matlab-kosher!