rep() {base}

rep() function replicates the values in x. It is a generic function.

rep.int and rep_len are faster simplified versions for two common cases. They are not generic.

rep(x, ...)

rep.int(x, times)

rep_len(x, length.out)

The parameters are:

• x : vector or factor to be repeated.
• times: an integer valued vector giving the times to repeat each element.
• length.out: length of the output
• each: the times each element in x is repeated

rep():

rep(1:3, times = 2) #from 1 to 3, 2 times.

## [1] 1 2 3 1 2 3

rep(1:3, 2)         #from 1 to 3, 2 times.

## [1] 1 2 3 1 2 3

rep(1:3, each = 2)  #from 1 to 3, each value 2 times    

## [1] 1 1 2 2 3 3

rep(1:3, c(2,2,2))  #time of each value from 1 to 3 is given by a vector

## [1] 1 1 2 2 3 3

rep(1:3, c(0,1,2))

## [1] 2 3 3

rep(1:3, each = 3, len = 3)    # 3 first values

## [1] 1 1 1

rep(1:3, each = 3, len = 12)   # 12 integers, 3 numbers are recycled

##  [1] 1 1 1 2 2 2 3 3 3 1 1 1

rep(1:3, each = 3, times = 3) 

##  [1] 1 1 1 2 2 2 3 3 3 1 1 1 2 2 2 3 3 3 1 1 1 2 2 2 3 3 3

rep.int():

x = data.frame(1:10,21:30)
colnames(x) = c('A','B') 
x

##     A  B
## 1   1 21
## 2   2 22
## 3   3 23
## 4   4 24
## 5   5 25
## 6   6 26
## 7   7 27
## 8   8 28
## 9   9 29
## 10 10 30

rep(x, times = 2) 

## $A
##  [1]  1  2  3  4  5  6  7  8  9 10
## 
## $B
##  [1] 21 22 23 24 25 26 27 28 29 30
## 
## $A
##  [1]  1  2  3  4  5  6  7  8  9 10
## 
## $B
##  [1] 21 22 23 24 25 26 27 28 29 30

rep.int(x, times = 2)

## [[1]]
##  [1]  1  2  3  4  5  6  7  8  9 10
## 
## [[2]]
##  [1] 21 22 23 24 25 26 27 28 29 30
## 
## [[3]]
##  [1]  1  2  3  4  5  6  7  8  9 10
## 
## [[4]]
##  [1] 21 22 23 24 25 26 27 28 29 30

rep_len():

rep(1,6)

## [1] 1 1 1 1 1 1

rep_len(1,6) #same result

## [1] 1 1 1 1 1 1

rep(1:5, 10) #number of times = 10

##  [1] 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5
## [36] 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5

rep_len(1:5, 10) #length = 10

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

par(mfrow = c(2,2))
y = c(1,2,3)
plot(y, type = 'b', col = 'gold')
plot(rep(y, time = 2), type = 'b', col = 'darkturquoise')
plot(rep(y, time = 2, each = 2), type = 'b', col = 'darkviolet')
plot(rep(y, time = 2, each = 2, len = 6), type = 'b', col = 'deeppink')