# Array of StaticArrays to 2D array

**URL:** <https://discourse.julialang.org/t/array-of-staticarrays-to-2d-array/29772>\
**Category:** New to Julia\
**Created:** [October 11, 2019, 11:59am UTC](https://discourse.julialang.org/t/array-of-staticarrays-to-2d-array/29772 "2019-10-11T11:59:12Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![aplavin](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/aplavin/32/222056_2.png) [@aplavin](https://discourse.julialang.org/u/aplavin)\
**Post date:** [October 11, 2019, 11:59am UTC](https://discourse.julialang.org/t/array-of-staticarrays-to-2d-array/29772/1 "2019-10-11T11:59:12Z")

</div>

StaticArrays documentation gives a way to convert a 2D array of values to a 1D array of StaticArrays: `reinterpret(SVector{N,T}, vec(x))`. However I cannot find it anywhere how to perform the opposite conversion - from a 1D array of StaticArrays to 2D array of plain values, also without copying any data. Is it possible at all?

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<div class="post-metadata">

**Author:** ![rdeits](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/rdeits/32/286_2.png) [@rdeits](https://discourse.julialang.org/u/rdeits)\
**Post date:** [October 11, 2019, 12:34pm UTC](https://discourse.julialang.org/t/array-of-staticarrays-to-2d-array/29772/2 "2019-10-11T12:34:45Z")

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Yes, you can do the reverse operation by reinterpreting as T and then reshaping. There’s also no need to call `vec(x)`:

```julia
julia> x = rand(2, 3)
2×3 Array{Float64,2}:
 0.0929609 0.827564 0.622823
 0.314605 0.221642 0.066153

julia> y = reinterpret(SVector{2, Float64}, x)
1×3 reinterpret(SArray{Tuple{2},Float64,1,2}, ::Array{Float64,2}):
 [0.0929609, 0.314605] [0.827564, 0.221642] [0.622823, 0.066153]

julia> z = reshape(reinterpret(Float64, y), 2, :)
2×3 reshape(reinterpret(Float64, reinterpret(SArray{Tuple{2},Float64,1,2}, ::Array{Float64,2})), 2, 3) with eltype Float64:
 0.0929609 0.827564 0.622823
 0.314605 0.221642 0.066153

```

We can verify that x, y, and z all share their underlying data:

```julia
julia> x[1, 1] = 2
2

julia> y
1×3 reinterpret(SArray{Tuple{2},Float64,1,2}, ::Array{Float64,2}):
 [2.0, 0.314605] [0.827564, 0.221642] [0.622823, 0.066153]

julia> z
2×3 reshape(reinterpret(Float64, reinterpret(SArray{Tuple{2},Float64,1,2}, ::Array{Float64,2})), 2, 3) with eltype Float64:
 2.0 0.827564 0.622823
 0.314605 0.221642 0.066153

```

**Edit** : actually, calling `vec` is fine–it ensures that y is actually 1D, rather than being a 1xM matrix as in my code above. You can either do:

```julia
julia> y = reinterpret(SVector{2, Float64}, vec(x))
3-element reinterpret(SArray{Tuple{2},Float64,1,2}, ::Array{Float64,1}):
 [5.0, 0.314605]     
 [0.827564, 0.221642]
 [0.622823, 0.066153]

```

or:

```julia
julia> y = reshape(reinterpret(SVector{2, Float64}, x), :)
3-element reshape(reinterpret(SArray{Tuple{2},Float64,1,2}, ::Array{Float64,2}), 3) with eltype SArray{Tuple{2},Float64,1,2}:
 [5.0, 0.314605]     
 [0.827564, 0.221642]
 [0.622823, 0.066153]

```