Rotates an array about two specified dimensions

Rotates an array about two specified dimensions by any number of 90 degree turns

Usage

arot(a, rights = 1,pair=1:2)

Arguments

a

The array to be rotated

rights

Integer; number of right angles to turn

pair

A two-element vector containing the dimensions to rotate with default meaning to rotate about the first two dimensions

Author

Robin K. S. Hankin

Note

Function arot() is not exactly equivalent to octave's rotdim(); in arot() the order of the elements of pair matters because the rotation is clockwise when viewed in the (pair[1],pair[2]) direction. Compare octave's rotdim() in which pair is replaced with sort(pair).

Note also that the rotation is about the first two dimensions specified by pair but if pair has more than two elements then these dimensions are also permuted.

Also note that function arot() does not treat singleton dimensions specially.

See also

arev

Examples

a <- array(1:16,rep(2,4))
arot(a)
#> , , 1, 1
#> 
#>      [,1] [,2]
#> [1,]    3    4
#> [2,]    1    2
#> 
#> , , 2, 1
#> 
#>      [,1] [,2]
#> [1,]    7    8
#> [2,]    5    6
#> 
#> , , 1, 2
#> 
#>      [,1] [,2]
#> [1,]   11   12
#> [2,]    9   10
#> 
#> , , 2, 2
#> 
#>      [,1] [,2]
#> [1,]   15   16
#> [2,]   13   14
#>