1\name{process} 2\alias{process} 3\title{Force index arrays into range} 4\description{ 5Forces an (integer) array to have entries in the range 1-n, by (i) 6taking the entries modulo n, then (ii) setting zero elements to n. 7Useful for modifying index arrays into a form suitable for use with 8magic squares.} 9\usage{ 10process(x, n) 11} 12\arguments{ 13 \item{x}{Index array to be processed} 14 \item{n}{Modulo of arithmetic to be used} 15} 16\author{Robin K. S. Hankin} 17\examples{ 18# extract the broken diagonal of magic.2np1(4) that passes 19# through element [1,5]: 20 21a <- magic.2np1(4) 22index <- t(c(1,5)+rbind(1:9,1:9)) 23a[process(index,9)] 24} 25\keyword{array} 26