\HeaderA{GetColor}{A function to get the Red-Blue color scheme used by dChip}{GetColor}
\aliasA{dChip.colors}{GetColor}{dChip.colors}
\aliasA{greenred.colors}{GetColor}{greenred.colors}
\keyword{manip}{GetColor}
\begin{Description}\relax
A simple, vectorized function that computes a Red/Blue color for
plotting microarray expression data.
\end{Description}
\begin{Usage}
\begin{verbatim}
GetColor(value, GreenRed=FALSE, DisplayRange=3)
dChip.colors(n)
greenred.colors(n)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{value}] The vector of expression values. 
\item[\code{GreenRed}] If \code{TRUE} the Green-Red colors are produced,
otherwise Red-Blue are procduced. 
\item[\code{DisplayRange}] A parameter controlling the range of
\code{value}'s that will be plotted. 
\item[\code{n}] An integer saying how many colors to be in the palette.
\end{ldescription}
\end{Arguments}
\begin{Details}\relax
\code{GetColor} is a simple mapping into RGB land provided by Cheng
Li.
\code{dChip.colors} provides functionality similar to that of
\code{\LinkA{topo.colors}{topo.colors}} for the red--blue colors used for genome
plots. \code{greenred.colors} does the same for the green-black-red gradient.
\end{Details}
\begin{Value}
A vector of RGB colors suitable for plotting in R.
\end{Value}
\begin{Author}\relax
R. Gentleman, based on an original by C. Li.
\end{Author}
\begin{Examples}
\begin{ExampleCode}
  set.seed(10)
  x <- rnorm(10)
  GetColor(x)
  dChip.colors(10)
\end{ExampleCode}
\end{Examples}