numeric<-c(100, 200, 400, 600, 800)
factor.numeric<-as.factor(numeric)
factor.numeric

## [1] 100 200 400 600 800
## Levels: 100 200 400 600 800

c(2,5,6,9) 

## [1] 2 5 6 9

rep(2,times=4) 

## [1] 2 2 2 2

seq(from=3, to=21, by=3 )

## [1]  3  6  9 12 15 18 21

runif(10, min = 0, max= 1)

##  [1] 0.88639260 0.52909127 0.20897873 0.60000384 0.15171817 0.42604188
##  [7] 0.34741427 0.19997390 0.67636111 0.05715733

rnorm(10, mean = 0, sd = 1)

##  [1] -1.9781073 -0.3621088 -1.0146453  1.1798615 -1.7046093  0.6592655
##  [7] -0.3630556  0.1116167  1.2973099  0.2774585