tfrpwv.tex

时频分析的工具包

% This is part of the TFTB Reference Manual.
% Copyright (C) 1996 CNRS (France) and Rice University (US).
% See the file refguide.tex for copying conditions.


\markright{tfrpwv}
\hspace*{-1.6cm}{\Large \bf tfrpwv}

\vspace*{-.4cm}
\hspace*{-1.6cm}\rule[0in]{16.5cm}{.02cm}
\vspace*{.2cm}

{\bf \large \fontfamily{cmss}\selectfont Purpose}\\
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\begin{minipage}[t]{13.5cm}
Pseudo Wigner-Ville time-frequency distribution.
\end{minipage}
\vspace*{.5cm}

{\bf \large \fontfamily{cmss}\selectfont Synopsis}\\
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\begin{minipage}[t]{13.5cm}
\begin{verbatim}
[tfr,t,f] = tfrpwv(x)
[tfr,t,f] = tfrpwv(x,t)
[tfr,t,f] = tfrpwv(x,t,N)
[tfr,t,f] = tfrpwv(x,t,N,h)
[tfr,t,f] = tfrpwv(x,t,N,h,trace)
\end{verbatim}
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{\bf \large \fontfamily{cmss}\selectfont Description}\\
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\begin{minipage}[t]{13.5cm}
        {\ty tfrpwv} computes the pseudo Wigner-Ville distribution of a
        discrete-time signal {\ty x}, or the cross pseudo Wigner-Ville
        distribution between two signals. The pseudo Wigner-Ville
        distribution writes
\[PW_x(t,\nu)=\int_{-\infty}^{+\infty} h(\tau)\ x(t+\tau/2)\ x^*(t-\tau/2)\
e^{-j2\pi \nu \tau}\ d\tau.\]

\hspace*{-.5cm}\begin{tabular*}{14cm}{p{1.5cm} p{8cm} c}
Name & Description & Default value\\
\hline
        {\ty x}     & signal if auto-PWV, or {\ty [x1,x2]} if cross-PWV
			({\ty Nx=length(x)}) \\ 
        {\ty t}     & time instant(s)          & {\ty (1:Nx)}\\
        {\ty N}     & number of frequency bins & {\ty Nx}\\
        {\ty h}     & frequency smoothing window, in the time-domain,
                {\ty h(0)} being forced to {\ty 1}   & {\ty window(odd(N/4))}\\ 
        {\ty trace}  & if nonzero, the progression of the algorithm is shown
                                         & {\ty 0}\\
     \hline {\ty tfr}   & time-frequency representation \\
        {\ty f}     & vector of normalized frequencies\\

\hline
\end{tabular*}
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When called without output arguments, {\ty tfrpwv} runs {\ty tfrqview}.
\end{minipage}
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{\bf \large \fontfamily{cmss}\selectfont Example}
\begin{verbatim}
         sig=fmlin(128,0.1,0.4); 
         tfrpwv(sig);
\end{verbatim}

\newpage

{\bf \large \fontfamily{cmss}\selectfont See Also}\\
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\begin{minipage}[t]{13.5cm}
all the {\ty tfr*} functions.
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{\bf \large \fontfamily{cmss}\selectfont Reference}\\
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\begin{minipage}[t]{13.5cm}
[1] T. Claasen, W. Mecklenbrauker ``The Wigner Distribution - A Tool for
Time-Frequency Signal Analysis'' {\it 3 parts} Philips
J. Res., Vol. 35, No. 3, 4/5, 6, pp. 217-250, 276-300, 372-389, 1980.
\end{minipage}