\name{count.overplot}
\alias{count.overplot}
\title{Show overlying points as counts}
\usage{
 count.overplot(x,y,tol=NULL,col=par("fg"),pch="1",...)
}
\arguments{
 \item{x,y}{Two numeric data vectors or the first two columns of a matrix
  or data frame. Typically the x/y coordinates of points to be plotted.}
 \item{tol}{The largest distance between points that will be considered
  to be overlying.}
 \item{col}{Color(s) for the points (not the numbers).}
 \item{pch}{Symbol(s) to display.}
 \item{...}{additional arguments passed to \samp{plot}.}
}
\description{
 \samp{count.overplot} checks for overlying points defined as points
  separated by a maximum of \samp{tol}, a two element numeric vector of
  the x and y tolerance.  Defaults to 1/2 of the width of a lower case 
  "o" in the x direction and 1/2 of the height of a lower case "o" in 
  the y direction.
}
\value{nil}
\keyword{misc}
\author{Jim Lemon}
\seealso{\link{cluster.overplot},\link{sizeplot}}
\examples{
 xy.mat<-cbind(sample(1:10,200,TRUE),sample(1:10,200,TRUE))
 count.overplot(xy.mat,main="count.overplot",
  xlab="X values",ylab="Y values")
}