Menu
I'd like to get the number of rows of a dataframe.
I can achieve that with size(myDataFrame)[1].
Is there a cleaner way ?
495
Julia has a library to handle tabular data, in a way similar to R or Pandas dataframes. The name is, no surprises, DataFrames. The approach and the function names are similar, although the way of actually accessing the API may be a bit different.
Steps to Create a DataFrame in Julia from Scratch You can then use the following template to create a DataFrame in Julia: using DataFrames df = DataFrame(column_1 = ["value_1", "value_2", "value_3", ...], column_2 = ["value_1", "value_2", "value_3", ...], column_3 = ["value_1", "value_2", "value_3", ...], ... )
Create an empty Julia DataFrame by enclosing column names and datatype of column inside DataFrame() function. Now you can add rows one by one using push!() function. This is like row binding.
If you are using DataFrames specifically, then you can use nrow():
julia> df = DataFrame(Any[1:10, 1:10]);
julia> nrow(df)
10
Alternatively, you can specify the dimension argument for size:
julia> size(df, 1)
10
This also work for arrays as well so it's a bit more general:
julia> my_array = rand(4, 3)
4×3 Array{Float64,2}:
0.980798 0.873643 0.819478
0.341972 0.34974 0.160342
0.262292 0.387406 0.00741398
0.512669 0.81579 0.329353
julia> size(my_array, 1)
4
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
