MaskedArrays.jl allows you to associated a bitmask with an array non-destructively. Any elements with a masked value of false are zero, while other elements are passed through. The original array is not modified. It provides two types: MaskedArray and MaskedSliceArray. Nothing is exported.
julia> x = rand(4, 5)
4×5 Matrix{Float64}:
0.45442 0.323381 0.245189 0.9963 0.901239
0.867445 0.358103 0.428182 0.888031 0.800996
0.116383 0.499893 0.0768902 0.614683 0.23086
0.840305 0.564109 0.477627 0.104402 0.0891596
julia> m = x .< 0.5
4×5 BitMatrix:
1 1 1 0 0
0 1 1 0 0
1 1 1 0 1
0 0 1 1 1
julia> mask(x, m)
4×5 MaskedArray{Float64, 2, Matrix{Float64}}:
0.45442 0.323381 0.245189 0.0 0.0
0.0 0.358103 0.428182 0.0 0.0
0.116383 0.499893 0.0768902 0.0 0.23086
0.0 0.0 0.477627 0.104402 0.0891596You can also pass a Vector of indices to mask elements.
julia> x = ones(3, 2)
3×2 Matrix{Float64}:
1.0 1.0
1.0 1.0
1.0 1.0
julia> mask(x, [1, 5])
3×2 MaskedArray{Float64, 2, Matrix{Float64}}:
1.0 0.0
0.0 1.0
0.0 0.0Even complete slices of dimensions can be masked.
julia> mask(x, 1:2, :, :)
3×2×2 MaskedSliceArray{Float64, 3, Array{Float64, 3}, Tuple{UnitRange{Int64}, Base.Slice{Base.OneTo{Int64}}, Base.Slice{Base.OneTo{Int64}}}}:
[:, :, 1] =
0.69798 0.353225
0.646014 0.20619
0.0 0.0
[:, :, 2] =
0.318028 0.276218
0.508333 0.274718
0.0 0.0The original array can be obtained with unmask, and the masking can be made permanent with freeze.