R: Convert (x,y)-coordinates to single-number indices and back.

i2xy {mm74av2mmense7cdf}

R Documentation

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

`x`	numeric. x-coordinate (from 1 to 640)
`y`	numeric. y-coordinate (from 1 to 640)
`i`	numeric. single-number index (from 1 to 409600)

Details

Type i2xy and xy2i at the R prompt to view the function definitions.

Examples

  xy2i(5,5)
  i     = 1:(640*640)
  coord = i2xy(i)
  j     = xy2i(coord[, "x"], coord[, "y"])
  stopifnot(all(i==j))
  range(coord[, "x"])
  range(coord[, "y"])