\name{i2xy} \alias{i2xy} \alias{xy2i} \title{Convert (x,y)-coordinates to single-number indices and back.} \description{Convert (x,y)-coordinates on the chip (and in the CEL file) to the single-number indices used in AffyBatch and CDF environment, and back.} \usage{i2xy(i) xy2i(x,y) } \arguments{ \item{x}{numeric. x-coordinate (from 1 to 732)} \item{y}{numeric. y-coordinate (from 1 to 732)} \item{i}{numeric. single-number index (from 1 to 535824)} } \details{Type \code{i2xy} and \code{xy2i} at the \R prompt to view the function definitions.} \seealso{\code{\link{porcinecdf}}} \keyword{datasets} \examples{ xy2i(5,5) i = 1:(732*732) coord = i2xy(i) j = xy2i(coord[, "x"], coord[, "y"]) stopifnot(all(i==j)) range(coord[, "x"]) range(coord[, "y"]) }