function [tfr,t,f] = tfrwv(x,t,N,trace);
%TFRWV Wigner-Ville time-frequency distribution.
% [TFR,T,F]=TFRWV(X,T,N,TRACE) computes the Wigner-Ville distribution
% of a discrete-time signal X,
% or the cross Wigner-Ville representation between two signals.
%
% X : signal if auto-WV, or [X1,X2] if cross-WV.
% 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, TFRWV runs TFRQVIEW.
% F : vector of normalized frequencies.
%
% Example :
% sig=fmlin(128,0.1,0.4); tfrwv(sig);
%
% 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).
%
% This program is free software; you can redistribute it and/or modify
% it under the terms of the GNU General Public License as published by
% the Free Software Foundation; either version 2 of the License, or
% (at your option) any later version.
%
% This program is distributed in the hope that it will be useful,
% but WITHOUT ANY WARRANTY; without even the implied warranty of
% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
% GNU General Public License for more details.
%
% You should have received a copy of the GNU General Public License
% along with this program; if not, write to the Free Software
% Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
if (nargin == 0),
error('At least one 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('Wigner-Ville distribution'); end;
for icol=1:tcol,
ti= t(icol); taumax=min([ti-1,xrow-ti,round(N/2)-1]);
tau=-taumax:taumax; indices= rem(N+tau,N)+1;
tfr(indices,icol) = x(ti+tau,1) .* conj(x(ti-tau,xcol));
tau=round(N/2);
if (ti<=xrow-tau)&(ti>=tau+1),
tfr(tau+1,icol) = 0.5 * (x(ti+tau,1) * conj(x(ti-tau,xcol)) + ...
x(ti-tau,1) * conj(x(ti+tau,xcol))) ;
end;
if trace, disprog(icol,tcol,10); end;
end;
tfr= fft(tfr);
if (xcol==1), tfr=real(tfr); end ;
if (nargout==0),
tfrqview(tfr,x,t,'tfrwv');
elseif (nargout==3),
f=(0.5*(0:N-1)/N)';
end;
这个trf的代码引用总是出错，有没有大神看是哪里的问题