% fields, Tools for spatial data
% Copyright 2004-2011, Institute for Mathematics Applied Geosciences
% University Corporation for Atmospheric Research
% Licensed under the GPL -- www.gpl.org/licenses/gpl.html

\name{bplot.xy}
\alias{bplot.xy}
\title{
  Boxplots for conditional distribution 
}
\description{
Draws boxplots for y by binning on x. This gives a coarse, but quick,  
representation
of the conditional distrubtion of [Y|X] in terms of boxplots.  
}
\usage{
bplot.xy(x, y, N = 10, breaks = pretty(x, N, eps.correct = 1), plot=TRUE,
         ...)
}
\arguments{
\item{x}{
Vector to use for bin membership
}
\item{y}{
Vector to use for constructing boxplot statistics. 
}
\item{N}{
Number of bins on x. Default is 10.
}
\item{breaks}{
Break points defining bin boundaries. These can be unequally spaced. 
}

\item{plot}{
If FALSE just returns a list with the statistics used for plotting the
box plots, bin centers, etc. --  More stuff than you can imagine!
}
\item{\dots }{
Any other optional arguments passed to the standard \code{boxplot} function. 
}
}
\seealso{
bplot, draw.bplot
}
\examples{
# condition on swim times to see how run times vary
bplot.xy( minitri$swim, minitri$run, N=5)

# bivariate normal corr= .8
set.seed( 123)
x<-rnorm( 2000)
y<- .8*x +  sqrt( 1- .8**2)*rnorm( 200)
#
bplot.xy(x,y)
#
bplot.xy( x,y, breaks=seq( -3, 3,,25) ,
                xlim =c(-4,4), ylim =c(-4,4), col="grey80", lwd=2)
points( x,y,col=3, cex=.5)
}
\keyword{hplot}
% docclass is function
% Converted by Sd2Rd version 1.21.