Convert data frame with label to array in julia

Question

I have a data frame with a header in Julia, but I need to convert this to an array for some filtering, there is a similar record that people suggest using:

iris[:, 1:3]

to get an array from a dataframe, but this method will not work with a dataframe with a header, any suggestion, what should I do?

data format:

FP | C1 | Cz | C2 ....
*  | *  | *  | *  ....
.  | .  | .  | .  ....
.  | .  | .  | .  ....
.  | .  | .  | .  ....

Answer 1

Have you tried convert(Matrix, iris[:,1:3])? eg,

julia> using DataFrames

julia> df = DataFrame(a = 1:4, b = 1:4, c = randn(4), d = randn(4))
4×4 DataFrame
│ Row │ a     │ b     │ c        │ d          │
│     │ Int64 │ Int64 │ Float64  │ Float64    │
├─────┼───────┼───────┼──────────┼────────────┤
│ 1   │ 1     │ 1     │ 1.72172  │ -0.377729  │
│ 2   │ 2     │ 2     │ 0.206415 │ -0.266014  │
│ 3   │ 3     │ 3     │ 1.03785  │ -0.0317582 │
│ 4   │ 4     │ 4     │ 0.632473 │ -0.409014  │

julia> convert(Matrix, df[:,1:3])
4×3 Array{Float64,2}:
 1.0  1.0  1.72172
 2.0  2.0  0.206415
 3.0  3.0  1.03785
 4.0  4.0  0.632473

Answer 2

The accepted answer is well suited to answer the question as indicated.

, DataFrame , - , , , , DataFrame . . https://dataframesjl.readthedocs.io/en/latest/subsets.html https://dataframesjl.readthedocs.io/en/latest/split_apply_combine.html.

(, , - , .)

Answer 3

convert, , convert(::Type{Array}, df::AbstractDataFrame) :

using DataFrames
convert(Matrix, df)

Matrix(df)

Answer 4

Julia 0.7 . , Matrix(df) .

Answer 5

convert(Array, iris[:,1:3]) Julia 1.1.1