\name{plot.stft}\alias{plot.stft}\title{Plot Short Time Fourier Transforms}\description{  An object of class \code{"stft"} is plotted as a gray scale image.  The x-axis corresponds to time, the y-axis to frequency.  If the  default colormap is used, dark regions in the plot correspond to high  values at the particular time/frequency location.}\usage{\method{plot}{stft}(x, col = gray(63:0/63), \dots)}\arguments{  \item{x}{An object of class \code{"stft"} as obtained by the function    \code{stft}.}  \item{col}{An optional colormap.  By default 64 gray values are used,    where white corresponds to the minimum value and black to the    maximum.}  \item{\dots}{further arguments to be passed to or from methods.}}\value{No return value. This function is only for plotting.}\author{Andreas Weingessel}\seealso{stft}\examples{x<-rnorm(500)y<-stft(x)plot(y)}\keyword{ts}