function [tfr,t,f] = tfrmmce(x,h,t,N,trace);%TFRMMCE Minimum mean cross-entropy combination of spectrograms.%	[TFR,T,F]=TFRMMCE(X,H,T,N,TRACE) computes the minimum mean %	cross-entropy combination of spectrograms using as %	windows the columns of the matrix H.% %	X     : signal.%	H     : frequency smoothing windows, the H(:,i) being normalized%	        so as to be of unit energy. %	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, TFRMMCE runs TFRQVIEW.%	F     : vector of normalized frequencies.%%	Example :%	 sig=fmlin(128,0.1,0.4); h=zeros(19,3);%	 h(10+(-5:5),1)=tftb_window(11); h(10+(-7:7),2)=tftb_window(15);  %	 h(10+(-9:9),3)=tftb_window(19); tfrmmce(sig,h);% %	See also all the time-frequency representations listed in%	 the file CONTENTS (TFR*)%	F. Auger, August 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.org[xrow,xcol] = size(x);if (nargin < 2), error('At least 2 parameters are required');elseif (nargin==2), t=1:xrow; N=xrow; trace=0;elseif (nargin==3), N=xrow; trace=0;elseif (nargin==4), trace=0;end;[trow,tcol] = size(t);if (xcol~=1), error('X must have only one column');elseif (trow~=1), error('T must only have one row');elseif (N<=0), error('N must be greater than zero'); elseif (2^nextpow2(N)~=N & nargin==5), fprintf('For a faster computation, N should be a power of two\n');end; [hrow,hcol]=size(h); Lh=(hrow-1)/2; if (rem(hrow,2)==0), error('H must have an odd number of lines');elseif hcol==1,  error('H must have at least two columns');end;h=h*diag(1.0 ./ sqrt(sum(abs(h).^2)));tfr= zeros (N,tcol);slides= zeros(N,hcol);if trace, disp('MMCE Spectrogram'); end;for icol=1:tcol, ti= t(icol); tau=-min([round(N/2)-1,Lh,ti-1]):min([round(N/2)-1,Lh,xrow-ti]); indices= rem(N+tau,N)+1; slides= zeros(N,hcol); if trace, disprog(icol,tcol,10); end; for ih=1:hcol,  slides(indices,ih)=x(ti+tau).*conj(h(Lh+1+tau,ih)); end; slides=abs(fft(slides)).^2; tfr(:,icol)=prod(slides')' .^(1/hcol);end;tfr=tfr*(sum(abs(x(t)).^2)/sum(sum(tfr)));if trace, fprintf('\n'); end;if (nargout==0), tfrqview(tfr,x,t,'tfrmmce',h);elseif (nargout==3), f=fftshift((-(N/2):(N/2)-1)/N)';end;