function [tfr,t,f] = tfrmh(x,t,N,trace);%TFRMH	Margenau-Hill time-frequency distribution.%	[TFR,T,F]=TFRMH(X,T,N,TRACE) computes the Margenau-Hill%	distribution of a discrete-time signal X, %	or the cross Margenau-Hill representation between two signals. % %	X     : signal if auto-MH, or [X1,X2] if cross-MH.%	T     : time instant(s)          (default : 1:length(X)).%	N     : number of frequency bins (default : length(X)).%	TRACE : if nonzero, the progression of the algorithm is shown%                                        (default : 0).%	TFR   : time-frequency representation. When called without %               output arguments, TFRMH runs TFRQVIEW.%	F     : vector of normalized frequencies.%%	Example :%	 sig=fmlin(128,0.1,0.4); tfrmh(sig,1:128,128,1);% %	See also  all the time-frequency representations listed in%	 the file CONTENTS (TFR*)%	F. Auger, May-August 1994, July 1995.%	Copyright (c) 1996 by CNRS (France).%%	------------------- CONFIDENTIAL PROGRAM -------------------- %	This program can not be used without the authorization of its%	author(s). For any comment or bug report, please send e-mail to %	f.auger@ieee.orgif (nargin == 0), error('At least 1 parameter required');end;[xrow,xcol] = size(x);if (nargin == 1), t=1:xrow; N=xrow; trace=0;elseif (nargin == 2), N=xrow; trace=0;elseif (nargin == 3), trace = 0;end;if (N<0), error('N must be greater than zero');end;[trow,tcol] = size(t);if (xcol==0) | (xcol>2), error('X must have one or two columns');elseif (trow~=1), error('T must only have one row'); elseif (2^nextpow2(N)~=N), fprintf('For a faster computation, N should be a power of two\n');end; tfr= zeros (N,tcol) ;  if trace, disp('Margenau-Hill distribution'); end;for icol=1:tcol, ti= t(icol); tau=-min([N-ti,xrow-ti]):(ti-1); indices= rem(N+tau,N)+1;  if trace, disprog(icol,tcol,10); end; tfr(indices,icol)=x(ti,1)*conj(x(ti-tau,xcol));end; tfr= real(fft(tfr)); if (nargout==0), tfrqview(tfr,x,t,'tfrmh');elseif (nargout==3), f=fftshift((-(N/2):(N/2)-1)/N)';end;