CODEWITHSUNDEEP
rloops
oercim
oercim

Reputation: 1848

loop and modular operation in R

I want to make such a loop using R.

for i=1 output will be

1
2
3

for i=2 output will be

2
3
1

for i=3 output will be

3
1
2

Namely the outputs are successive integers. It is just when the integer reaches 4 it returns 1 and goes on. I guess I must use modular operations, how can I do that?

Upvotes: 0

Views: 47

Answers (2)

jogo
jogo

Reputation: 12559

This is my solution:

f <- function(i) { x <- i:(i+2) %% 3; x[x==0] <- 3; x }
for (i in 1:5) print(f(i))

Here is a second solution:

r <- matrix(c(3,1,2, 1,2,3, 2,3,1),3)
for (i in 1:5) print(r[i %% 3 + 1,])

Upvotes: 2

MrFlick
MrFlick

Reputation: 206243

If you have

a <- 1:3

for a value if i, you get the the sequence with

f <- function(i) (a+i+1) %% length(a) +1
f(1)
# [1] 1 2 3
f(2)
# [1] 2 3 1
f(3)
# [1] 3 1 2
f(4)
# [1] 1 2 3

Note that it starts over again at 4

Upvotes: 3

Related Questions