R: Force index arrays into range

process {magic} | R Documentation

## Force index arrays into range

### Description

Forces an (integer) array to have entries in the range 1-n, by (i) taking the entries modulo n, then (ii) setting zero elements to n. Useful for modifying index arrays into a form suitable for use with magic squares.

### Usage

    process(x, n)

### Arguments

`x` | Index array to be processed
`n` | Modulo of arithmetic to be used

### Author(s)

Robin K. S. Hankin

### Examples

    # extract the broken diagonal of magic.2np1(4) that passes
    # through element [1,5]:

    a <- magic.2np1(4)
    index <- t(c(1,5)+rbind(1:9,1:9))
    a[process(index,9)]

[Package magic version 1.5-6 Index]