arow {magic}

Generalized row and col

Description

Given an array, returns an array of the same size whose elements are sequentially numbered along the i^{\rm th} dimension.

Usage

arow(a, i)

Arguments

a

array to be converted

i

Number of the dimension

Value

An integer matrix with the same dimensions as a, with element \left(n_1,n_2,\ldots n_d\right) being n_i.

Note

This function is equivalent to, but faster than, function(a,i){do.index(a,function(x){x[i]})}. However, it is much more complicated.

The function is nominally the same as slice.index() but I have not checked all the edge cases.

Author(s)

Robin K. S. Hankin

Examples

a <- array(0,c(3,3,2,2))
arow(a,2)
(arow(a,1)+arow(a,2)+arow(a,3)+arow(a,4))%%2