function [tfr,t,f] = tfrsp(x,t,N,h,trace);%TFRSP	Spectrogram time-frequency distribution.%	[TFR,T,F]=TFRSP(X,T,N,H,TRACE) computes the Spectrogram %	distribution of a discrete-time signal X. % %	X     : signal.%	T     : time instant(s)          (default : 1:length(X)).%	N     : number of frequency bins (default : length(X)).%	H     : analysis window, H being normalized so as to%	        be  of unit energy.      (default : Hamming(N/4)). %	TRACE : if nonzero, the progression of the algorithm is shown%	                                 (default : 0).%	TFR   : time-frequency representation. When called without %	        output arguments, TFRSP runs TFRQVIEW.%	F     : vector of normalized frequencies.%%	Example :%	 sig=fmlin(128,0.1,0.4);%	 h=window(17,'Kaiser'); tfrsp(sig,1:128,64,h,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.rog if (nargin == 0), error('At least 1 parameter required');end;[xrow,xcol] = size(x);if (nargin < 1), error('At least 1 parameter is required');elseif (nargin <= 2), N=xrow;end;hlength=floor(N/4);hlength=hlength+1-rem(hlength,2);if (nargin == 1), t=1:xrow; h = window(hlength); trace=0;elseif (nargin == 2) | (nargin == 3), h = window(hlength); trace=0;elseif (nargin == 4), 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; [hrow,hcol]=size(h); Lh=(hrow-1)/2;if (hcol~=1)|(rem(hrow,2)==0), error('H must be a smoothing window with odd length');end;tfr= zeros (N,tcol) ;  if trace, disp('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;  if trace, disprog(icol,tcol,10); end; tfr(indices,icol)=x(ti+tau).*conj(h(Lh+1+tau))/norm(h(Lh+1+tau));end;%------icol=1,ti=1,tau=0,1,2,3,4,5,6,indices=1,2,3,4,5,6,7----------speech1000          % tfr(1,1)=x(1).*h(7)/1.8107=-2.1359, tfr(2,1)=x(2).*h(8)/1.8107=-2.4651,tfr(3,1)=x(3).*h(9)/1.8107=-2.2424,% tfr(4,1)=x(4).*h(10)/1.8107=-2.0141,tfr(5,1)=x(5).*h(11)/1.8107=-1.3516,tfr(6,1)=x(6).*h(12)/1.8107=-0.84225,% tfr(7,1)=x(7).*h(13)/1.8107=-0.51658%------icol=2,ti=2,tau=-1,0,1,2,3,4,5,6,indices=256,1,2,3,4,5,6,7% tfr(256,2)=x(1).*h(6)/2.0468=-1.8034,tfr(1,2)=x(2).*h(7)/2.0468=-2.2848,tfr(2,2)=x(3).*h(8)/2.0468=-2.2899,% tfr(3,2)=x(4).*h(9)/2.0468=-2.2933,tfr(4,2)=x(5).*h(10)/2.0468=-1.7550,tfr(5,2)=x(6).*h(11)/2.0468=-1.2879,% tfr(6,2)=x(7).*h(12)/2.0468=-0.9216,tfr(7,2)=x(8).*h(13)/2.0468=-0.4805% 分析窗h先由正半側(cè)由第1個樣值x(1),x(2),x(3),x(4),x(5),x(6),x(7),向最后1個樣值x(256)滑行;最后與樣值x(250),x(251),% x(253),x(254),x(255),x(256),對應(yīng)相乘的窗h(1),h(2),h(3),h(4),h(5),h(6),h(7).tfr=abs(fft(tfr)).^2;                           % ***  tfr (Nxtcol) 矩陣，行指頻點(diǎn)，列指時間  ***% tfr第1列：% (1) 133.81% (2) 133.58% (3) 132.88% (4) 131.71% (5) 130.1% ...        第1，129行單獨(dú)成行；第2行到第128行(127行)與第256行到第130行(127行)以第129行為軸上下對應(yīng) % (127)0.83925% (128)0.85153% (129)0.85567% (130)0.85153% (131)0.83925% ...       只取第1行到129行可作為，0到4000Hz頻率范圍% (253)130.1% (254)131.71% (255)132.88% (256)133.58if trace, fprintf('\n'); end;if (nargout==0), tfrqview(tfr,x,t,'tfrsp',h);elseif (nargout==3), f=fftshift((-N/2:N/2-1)/N)';end;