rep()

rep(x, times = 1, length.out = NA, each = 1) is pretty useful for simulating data. Here are some common recipes:

• Repeat a single number (1) a number of times (10)

rep(1, 10)

 [1] 1 1 1 1 1 1 1 1 1 1

• Repeat a series of numbers (1:5) a number of times (2)

rep(1:5, 2)

 [1] 1 2 3 4 5 1 2 3 4 5

rep(1:5, times=2)

 [1] 1 2 3 4 5 1 2 3 4 5

• If times is not an integer, it is truncated (not rounded).

rep(1:5, times=2.9)

 [1] 1 2 3 4 5 1 2 3 4 5

• Repeat a series of numbers (1:5) a number of times each (2)

rep(1:5, each=2)

 [1] 1 1 2 2 3 3 4 4 5 5

rep(1:5, 1, NA, 2)

 [1] 1 1 2 2 3 3 4 4 5 5

• Repeat a list of numbers (0, 3, 6) a number of times (2)

rep(c(0, 3, 6), times=2)

[1] 0 3 6 0 3 6

• Repeat a list of strings (“a”, “b”, “c”) a number of times (2)

rep(c("a", "b", "c"), times=2)

[1] "a" "b" "c" "a" "b" "c"

• Repeat a list of strings (“a”, “b”, “c”) a number of times each (2)

rep(c("a", "b", "c"), each=2)

[1] "a" "a" "b" "b" "c" "c"

• Repeat a list of strings (“a”, “b”) a number of times each (2) a number of times (3)

rep(c("a", "b"), each=2, times=3)

 [1] "a" "a" "b" "b" "a" "a" "b" "b" "a" "a" "b" "b"

• Repeat a series of numbers (1:5) until you have a specific total (12)

rep(1:5, length.out=12)

 [1] 1 2 3 4 5 1 2 3 4 5 1 2

rep_len(1:5, 12)

 [1] 1 2 3 4 5 1 2 3 4 5 1 2

• length.out overrides times

rep(1:5, length.out=12, times=500)

 [1] 1 2 3 4 5 1 2 3 4 5 1 2

• Repeat a sequence of numbers (0:10 by 5s) a number of times (3)

rep(seq(0, 10, by=5), 3)

[1]  0  5 10  0  5 10  0  5 10