# Converting nested vectors of Any

**URL:** <https://discourse.julialang.org/t/converting-nested-vectors-of-any/97012>\
**Category:** New to Julia\
**Created:** [April 3, 2023, 1:12pm UTC](https://discourse.julialang.org/t/converting-nested-vectors-of-any/97012 "2023-04-03T13:12:38Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![kingoslo](https://avatars.discourse-cdn.com/v4/letter/k/7cd45c/32.png) [@kingoslo](https://discourse.julialang.org/u/kingoslo)\
**Post date:** [April 3, 2023, 1:12pm UTC](https://discourse.julialang.org/t/converting-nested-vectors-of-any/97012/1 "2023-04-03T13:12:38Z")

</div>

Hello there,

I have parsed json from a file. According to the language that made the data, it contains a “collection” of matrices of 64-bit floats. But it is being read in as a format involving `Any`:

```julia
julia> raw = JSON.parsefile(path)
julia> typeof(raw)
Dict{String, Any}
julia> typeof(raw["0"])
Vector{Any} (alias for Array{Any, 1})
julia> typeof(raw["0"][1])
Vector{Any} (alias for Array{Any, 1})
julia> typeof(raw["1"][1][1])
Float64
julia> size(raw)
100
julia> size(raw["1"])
96
julia> size(raw["1"][1])
3

```

Now I want to convert this to a 3 dimensional array that is indexed in the same way. The problem is that the only way that I have found to do it requires 12 or so lines of code. So there has to be some built-in function or functions that just casts this It is the right format (?) :

```julia
raw = JSON.parsefile(path)

m = length(raw)
n = length(raw["1"])
l = length(raw["1"][1])

v::Array{Float64,3} = Array{Float64}(undef, m, n, l)

for (i,(key,value)) in enumerate(raw)
    for (j, vec) in enumerate(value)
        v[i,j,:] = Float64.( vec )
    end
end

```

So my question is: How can I do this efficiently in a couple of lines instead of a dozen?

---

<div class="post-metadata">

**Author:** ![halov](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/halov/32/47025_2.png) [@halov](https://discourse.julialang.org/u/halov)\
**Post date:** [April 3, 2023, 2:06pm UTC](https://discourse.julialang.org/t/converting-nested-vectors-of-any/97012/2 "2023-04-03T14:06:35Z")

</div>

You can use hcat()

```julia
raw = JSON.parsefile(path)

m = length(raw)
n = length(raw["1"])
l = length(raw["1"][1])

result = zeros(Float64, (l, n, m))

for (i, (key, value)) in enumerate(raw)
    result[:, :, i] .= hcat([cat(Float64, vec...) for vec in value]...)
end

```

For each key-value pair, it converts the `Vector{Any}` to a matrix of `Float64` values using a list comprehension that applies the `cat` function to each vector in the collection and then concatenates them horizontally using `hcat` . The resulting matrix is then assigned to the corresponding slice of the 3-dimensional array.