Programming in R

Cheat Sheat and Examples

function	meaning
c(1,3,4,5)	create a vector
2:5	create a sequence (2,3,4,5)
y[3]	say y is a vector, take the 3rd entry out of y
seq(2,10, by=0.5)	create a sequence, start from 2, ending at 10, step size = 0.5
rep(1:3, times = 2)	repeat the sequence (1,2,3), 2 times, so get (1,2,3,1,2,3)
rep(1:3, each = 2)	repeat the sequence (1,2,3), each entry 2 times, so get (1,1,2,2,3,3)

if (i > 3)
{ 
  print(‘Yes’)
} else { 
  print(‘No’)
}

for (i in 1:4)
{ 
  j <- i + 10
  print(j) 
}

square <- function(x)
{
   squared <- x*x
   return(squared)
}

Distribution	sampling	density function	cumulative density function
Normal	rnorm	dnorm	pnorm
Poisson	rpois	dpois	ppois

Lecture Notes