# Operations on AxisArrays

**URL:** <https://discourse.julialang.org/t/operations-on-axisarrays/6906>\
**Category:** General Usage\
**Tags:** question\
**Created:** [November 6, 2017, 9:20am UTC](https://discourse.julialang.org/t/operations-on-axisarrays/6906 "2017-11-06T09:20:48Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![jw3126](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jw3126/32/3086_2.png) [@jw3126](https://discourse.julialang.org/u/jw3126)\
**Post date:** [November 6, 2017, 9:20am UTC](https://discourse.julialang.org/t/operations-on-axisarrays/6906/1 "2017-11-06T09:20:48Z")

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Adding two axis arrays, with equal axes forgets the axes and results in an ordinary array. Same for other operations. Is this a bug or expected behaviour? Is there a recommended way to apply operations without forgetting the axes?

```nohighlight
julia> using AxisArrays

julia> x_axis = Axis{:x}(1:3);

julia> arr = AxisArray(ones(3), x_axis)
1-dimensional AxisArray{Float64,1,...} with axes:
    :x, 1:3
And data, a 3-element Array{Float64,1}:
 1.0
 1.0
 1.0

julia> arr + arr
3-element Array{Float64,1}:
 2.0
 2.0
 2.0

julia> arr .+ arr
3-element Array{Float64,1}:
 2.0
 2.0
 2.0

julia> abs.(arr)
3-element Array{Float64,1}:
 1.0
 1.0
 1.0

julia> -arr
3-element Array{Float64,1}:
 -1.0
 -1.0
 -1.0

julia> Pkg.status("AxisArrays")
 - AxisArrays 0.2.0

```

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<div class="post-metadata">

**Author:** ![nalimilan](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/nalimilan/32/147_2.png) [@nalimilan](https://discourse.julialang.org/u/nalimilan)\
**Post date:** [November 6, 2017, 1:55pm UTC](https://discourse.julialang.org/t/operations-on-axisarrays/6906/2 "2017-11-06T13:55:15Z")

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I _think_ that’s just because it hasn’t been implemented yet. FWIW, you can use NamedArrays for now if you need this kind of thing.

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<div class="post-metadata">

**Author:** ![Balinus](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/balinus/32/243_2.png) [@Balinus](https://discourse.julialang.org/u/Balinus)\
**Post date:** [November 6, 2017, 8:04pm UTC](https://discourse.julialang.org/t/operations-on-axisarrays/6906/3 "2017-11-06T20:04:54Z")

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You might be interested in solutions found in this (closed) issue I started which address this question.

[Basic operators on AxisArrays](https://github.com/JuliaArrays/AxisArrays.jl/issues/126)

[https://github.com/JuliaArrays/AxisArrays.jl/issues/126](https://github.com/JuliaArrays/AxisArrays.jl/issues/126)