function out = tfdshift(in)% tfdshift -- Shift the spectrum of a TFD by pi radians.%%  Usage%    out = tfdshift(in)%%  Inputs%    in   time-frequency distribution%%  Outputs%    out  shifted time-frequency distribution% Copyright (C) -- see DiscreteTFDs/Copyrighterror(nargchk(1, 1, nargin));N = size(in, 1);M = ceil(N/2);out = [in(M+1:N,:) ; in(1:M,:)];