OffsetArrays.jl

OffsetArrays provides Julia users with arrays that have arbitrary indices, similar to those found in some other programming languages like Fortran.

Usage

You can construct such arrays as follows:

OA = OffsetArray(A, axis1, axis2, ...)

where you want OA to have axes (axis1, axis2, ...) and be indexed by values that fall within these axis ranges. Example:

using OffsetArrays
julia> A = Float64.(reshape(1:15, 3, 5))
3×5 Matrix{Float64}:
 1.0  4.0  7.0  10.0  13.0
 2.0  5.0  8.0  11.0  14.0
 3.0  6.0  9.0  12.0  15.0

julia> OA = OffsetArray(A, -1:1, 0:4) # OA will have axes (-1:1, 0:4)
3×5 OffsetArray(::Matrix{Float64}, -1:1, 0:4) with eltype Float64 with indices -1:1×0:4:
 1.0  4.0  7.0  10.0  13.0
 2.0  5.0  8.0  11.0  14.0
 3.0  6.0  9.0  12.0  15.0

julia> OA = OffsetArray(A, CartesianIndex(-1, 0):CartesianIndex(1, 4))
3×5 OffsetArray(::Matrix{Float64}, -1:1, 0:4) with eltype Float64 with indices -1:1×0:4:
[...]

julia> OA[-1,0], OA[1,4]
(1.0, 15.0)