fmconst.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{fmconst}
\hspace*{-1.6cm}{\Large \bf fmconst}

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



{\bf \large \fontfamily{cmss}\selectfont Purpose}\\
\hspace*{1.5cm}
\begin{minipage}[t]{13.5cm}
Signal with constant frequency modulation.
\end{minipage}
\vspace*{.5cm}


{\bf \large \fontfamily{cmss}\selectfont Synopsis}\\
\hspace*{1.5cm}
\begin{minipage}[t]{13.5cm}
\begin{verbatim}
[y,iflaw] = fmconst(N)
[y,iflaw] = fmconst(N,fnorm)
[y,iflaw] = fmconst(N,fnorm,t0)
\end{verbatim}
\end{minipage}
\vspace*{.5cm}


{\bf \large \fontfamily{cmss}\selectfont Description}\\
\hspace*{1.5cm}
\begin{minipage}[t]{13.5cm}
        {\ty fmconst} generates a frequency modulation with a constant
        frequency {\ty fnorm} and unit amplitude. The phase of this
        modulation, determined by {\ty t0}, is such that {\ty y(t0)=1}. The
        signal is analytic.\\
 
\hspace*{-.5cm}\begin{tabular*}{14cm}{p{1.5cm} p{8.5cm} c}
Name & Description & Default value\\
\hline
        {\ty N }    & number of points\\
        {\ty fnorm} & normalised frequency       & {\ty 0.25}\\
        {\ty t0}    & time center                & {\ty N/2}\\
  \hline {\ty y}    & signal\\
        {\ty iflaw} & instantaneous frequency law  \\

\hline
\end{tabular*}

\end{minipage}
\vspace*{1cm}


{\bf \large \fontfamily{cmss}\selectfont Example}\\
\hspace*{1.5cm}
\begin{minipage}[t]{13.5cm}
\begin{verbatim}
         z=amgauss(128,50,30).*fmconst(128,0.05,50);
         plot(real(z));
\end{verbatim}
represents the real part of a complex sinusoid of normalized frequency {\ty
0.05}, centered at {\ty t0=50}, and with a gaussian amplitude modulation
maximum at {\ty t=t0}.
\end{minipage}
\vspace*{.5cm}


{\bf \large \fontfamily{cmss}\selectfont See Also}\\
\hspace*{1.5cm}
\begin{minipage}[t]{13.5cm}
\begin{verbatim}
fmlin, fmsin, fmodany, fmhyp, fmpar, fmpower.
\end{verbatim}
\end{minipage}