📂Julia

Converting Between DataFrames and 2D Arrays in Julia

Code

Matrix(df) or Array(df) functions can be used to convert a DataFrame into an array of the same size. To create a DataFrame from an array, use DataFrame(array, :auto). In the past, the convert function was used, but it’s not applicable anymore, so be careful.

using DataFrames

julia> A = rand(5,3)
5×3 Matrix{Float64}:
 0.678876  0.10431    0.827079
 0.621647  0.372007   0.29346
 0.756844  0.171237   0.0732631
 0.922519  0.0535938  0.121689
 0.164058  0.0684278  0.68446

julia> df = DataFrame(A, :auto)
5×3 DataFrame
 Row │ x1        x2         x3        
     │ Float64   Float64    Float64
─────┼────────────────────────────────
   1 │ 0.678876  0.10431    0.827079
   2 │ 0.621647  0.372007   0.29346
   3 │ 0.756844  0.171237   0.0732631
   4 │ 0.922519  0.0535938  0.121689
   5 │ 0.164058  0.0684278  0.68446

julia> Matrix(df)
5×3 Matrix{Float64}:
 0.678876  0.10431    0.827079
 0.621647  0.372007   0.29346
 0.756844  0.171237   0.0732631
 0.922519  0.0535938  0.121689
 0.164058  0.0684278  0.68446

julia> Array(df)
5×3 Matrix{Float64}:
 0.678876  0.10431    0.827079
 0.621647  0.372007   0.29346
 0.756844  0.171237   0.0732631
 0.922519  0.0535938  0.121689
 0.164058  0.0684278  0.68446

julia> Array(df) == Matrix(df)
true