How to split a data frame?

Question

I want to split a data frame into several smaller ones. This looks like a very trivial question, however I cannot find a solution from web search.

Answer 1

You may also want to cut the data frame into an arbitrary number of smaller dataframes. Here, we cut into two dataframes.

x = data.frame(num = 1:26, let = letters, LET = LETTERS)
set.seed(10)
split(x, sample(rep(1:2, 13)))

gives

$`1`
   num let LET
3    3   c   C
6    6   f   F
10  10   j   J
12  12   l   L
14  14   n   N
15  15   o   O
17  17   q   Q
18  18   r   R
20  20   t   T
21  21   u   U
22  22   v   V
23  23   w   W
26  26   z   Z

$`2`
   num let LET
1    1   a   A
2    2   b   B
4    4   d   D
5    5   e   E
7    7   g   G
8    8   h   H
9    9   i   I
11  11   k   K
13  13   m   M
16  16   p   P
19  19   s   S
24  24   x   X
25  25   y   Y

You can also split a data frame based upon an existing column. For example, to create three data frames based on the cyl column in mtcars:

split(mtcars,mtcars$cyl)