\Header{plot.spec}{Plotting Spectral Densities}
\methalias{plot.spec.coherency}{plot.spec}
\methalias{plot.spec.phase}{plot.spec}
\keyword{hplot}{plot.spec}
\keyword{ts}{plot.spec}
\begin{Description}\relax
Plotting method for objects of class \code{"spec"}.  For multivariate
time series it plots the marginal spectra of the series or pairs plots
of the coherency and phase of the cross-spectra.
\end{Description}
\begin{Usage}
\begin{verbatim}
## S3 method for class 'spec':
plot(x, add = FALSE, ci = 0.95, log = c("yes", "dB", "no"),
     xlab = "frequency", ylab, type = "l", ci.col = "blue",
     main = NULL, sub = NULL,
     plot.type = c("marginal", "coherency", "phase"),
     ci.lty = 3, ...)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{x}] an object of class \code{"spec"}.
\item[\code{add}] logical.  If \code{TRUE}, add to already existing plot.
\item[\code{ci}] Coverage probability for confidence interval.  Plotting of
the confidence bar is omitted unless \code{ci} is strictly
positive.
\item[\code{log}] If \code{"dB"}, plot on log10 (decibel) scale (as S-PLUS),
otherwise use conventional log scale or linear scale.  Logical
values are also accepted.  The default is \code{"yes"} unless
\code{options(ts.S.compat = TRUE)} has been set, when it is
\code{"dB"}.
\item[\code{xlab}] the x label of the plot.
\item[\code{ylab}] the y label of the plot.
\item[\code{type}] the type of plot to be drawn, defaults to lines.
\item[\code{ci.col}] Colour for plotting confidence bar or confidence
intervals for coherency and phase.
\item[\code{main}] overall title for the plot.
\item[\code{sub}] a sub title for the plot.
\item[\code{plot.type}] For multivariate time series, the type of plot
required.  Only the first character is needed.
\item[\code{ci.lty}] line type for confidence intervals for coherency and
phase.
\item[\code{...}] Further graphical parameters.
\end{ldescription}
\end{Arguments}
\begin{SeeAlso}\relax
\code{\Link{spectrum}}
\end{SeeAlso}

