\name{selectArea}
\alias{selectArea}
\title{
Select an area in the heatmap
}
\description{
Select an area in the heatmap
}
\usage{
selectArea(mark = TRUE)
}
\arguments{

  \item{mark}{whether mark the selected area as a rectangle}

}
\details{
Users can use mouse to click two positions on the heatmap, the function
will return the row index and column index for the selected region in the selected matrix.

This function only works under interactive graphical environment.
}
\value{
A list containing row index and column index corresponding to the selected region.
}
\author{
Zuguang Gu <z.gu@dkfz.de>
}
\examples{
# No example for this function
NULL
}