1\name{xy.grid} 2\alias{xy.grid} 3\title{Produce regular grid matrix.} 4\description{ 5 Produce the grid used by \code{\link{persp}}, \link{contour}, etc, as 6 an \code{N x 2} matrix. 7 This is really outdated by \code{\link{expand.grid}()} nowadays. 8} 9\usage{ 10xy.grid(x, y) 11} 12\arguments{ 13 \item{x,y}{any vectors of same mode.} 14} 15\value{ 16 a 2-column matrix of \dQuote{points} for each combination of \code{x} and 17 \code{y}, i.e. with \code{length(x) * length(y)} rows. 18} 19\author{Martin Maechler, 26 Oct 1994.} 20\seealso{\code{\link{expand.grid}} which didn't exist when 21 \code{xy.grid} was first devised.} 22\examples{ 23plot(xy.grid(1:7, 10*(0:4))) 24 25x <- 1:3 ; y <- 10*(0:4) 26xyg <- xy.grid(x,y) 27 28## Compare with expand.grid() : 29m2 <- as.matrix(expand.grid(y,x)[, 2:1]) 30dimnames(m2) <- NULL 31stopifnot(identical(xyg, m2)) 32} 33\keyword{array} 34