DataFrames.jl (1)

Create dataframe

To create a dataframe, simply use DataFrame function after loding DataFrames.jl.

Following code produces a dataframe composed of three variables, A, B, and C, each of which has 500 rows. Each row of column A increments by 2 starting from integer 1. Column B repeats 50 times of each integer starting from 1. Coumn C lists integers from 1 to 500.

using DataFrames
df = DataFrame(A=1:2:1000, 
    B= repeat(1:10, inner=50), 
    C= 1:500)

first, last

The first and last functions act as head and tail function in R, which allow us to view the first or the last couple of rows of the dataset.

first(df, 10)

Output:

10×3 DataFrame
 Row │ A      B      C     
     │ Int64  Int64  Int64 
─────┼─────────────────────
   1 │     1      1      1
   2 │     3      1      2
   3 │     5      1      3
   4 │     7      1      4
   5 │     9      1      5
   6 │    11      1      6
   7 │    13      1      7
   8 │    15      1      8
   9 │    17      1      9
  10 │    19      1     10

last(df, 10)

Output:

10×3 DataFrame
 Row │ A      B      C     
     │ Int64  Int64  Int64 
─────┼─────────────────────
   1 │   981     10    491
   2 │   983     10    492
   3 │   985     10    493
   4 │   987     10    494
   5 │   989     10    495
   6 │   991     10    496
   7 │   993     10    497
   8 │   995     10    498
   9 │   997     10    499
  10 │   999     10    500

Reference

https://dataframes.juliadata.org/stable/man/working_with_dataframes/