[R] cut into groups of equal nr of elements...

[Marc Schwartz]

On Jul 17, 2013, at 4:43 PM, Witold E Wolski <wewolski at gmail.com> wrote:

> I would like to "cut" a vector into groups of equal nr of elements.
> looking for a function on the lines of cut but where I can specify
> the size of the groups instead of the nr of groups.



In addition to the other options, if the 'breaks' argument to cut() is a single number, rather than a vector of cut points, it defines the number of intervals to break the 'x' vector into, which of course you can derive from length(x) / size.

Thus:

set.seed(1)
Vec <- sample(30)

> Vec
 [1]  8 11 17 25  6 23 27 16 14  2  5  4 13  7 18 30 29 24 20  9 10 21
[23] 26  1 22 15 28 12  3 19


# Split into 5 groups of 6 each 

> split(Vec, cut(Vec, 5))
$`(0.971,6.78]`
[1] 6 2 5 4 1 3

$`(6.78,12.6]`
[1]  8 11  7  9 10 12

$`(12.6,18.4]`
[1] 17 16 14 13 18 15

$`(18.4,24.2]`
[1] 23 24 20 21 22 19

$`(24.2,30]`
[1] 25 27 30 29 26 28


Regards,

Marc Schwartz