I was playing with R a little bit and I came out with this behavior that I don't understand:
num <- seq(1,20,1)
num[num %% c(1,2) == 0]
[1] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
So it seems to be an analog expression of
num[num %% 1 == 0 | num %% 2 == 0]
But when I do the following gets weird:
num[num %% c(1,3) == 0]
[1] 1 3 5 6 7 9 11 12 13 15 17 18 19
num[num %% c(1,4) == 0]
[1] 1 3 4 5 7 8 9 11 12 13 15 16 17 19 20
I have been thinking about it, but I can't come out with an explanation for this. It's just out of curiosity, but if someone has a reason it would be very interesting to hear!.
Thanks!
As jogo says, it's the recycling rule.
The result of num %% 1 is
[1] 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
whilst the result of num %% 3 is
[1] 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2
Looking at the result of num %% c(1,3)
[1] 0 2 0 1 0 0 0 2 0 1 0 0 0 2 0 1 0 0 0 2
The first number in the result is taken from the first number of the num %% 1 result, the second from the second number of the num %% 3 result, the third from the third in num %% 1 and so on.