Question

When I create a dataframe I do:

dt = data.frame(a=c(1:5),b=c(1:20))
dt
   a  b
1  1  1
2  2  2
3  3  3
4  4  4
5  5  5
6  1  6
7  2  7
8  3  8
9  4  9
10 5 10
11 1 11
12 2 12
13 3 13
14 4 14
15 5 15
16 1 16
17 2 17
18 3 18
19 4 19
20 5 20

as you can see the value of the first column (a) are repeated.
How can I create different “columns” with different number of values?

Thanks
H

Answer 1

Use a list. A data.frame is a special kind of list in which all elements are of the same length.

list(a=c(1:5),b=c(1:20))
$a
[1] 1 2 3 4 5

$b
 [1]  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20