CodeMirror

X <- list(height = 5.4, weight = 54)

cat("Printing objects: "); print(X)

print("Accessing individual elements:")

cat(sprintf("Your height is %s and your weight is %s\n", X$height, X$weight))

​

# Functions:

square <- function(x) {

  return(x * x)

}

cat(sprintf("The square of 3 is %s\n", square(3)))

​

# In R, the last expression in a function is, by default, what is

# returned. The idiomatic way to write the function is:

square <- function(x) {

  x * x

}

# or, for functions with short content:

square <- function(x) x * x

​

# Function arguments with default values:

cube <- function(x = 5) x * x * x

cat(sprintf("Calling cube with 2 : %s\n", cube(2))  # will give 2^3

cat(sprintf("Calling cube        : %s\n", cube())   # will default to 5^3.

​

powers <- function(x) list(x2 = x*x, x3 = x*x*x, x4 = x*x*x*x)

​

cat("Powers of 3: "); print(powers(3))

​

# Data frames

df <- data.frame(letters = letters[1:5], '#letter' = 1:5)

print(df$letters)

print(df$`#letter`)

​

# Operators:

m1 <- matrix(1:6, 2, 3)

m2 <- m1 %*% t(m1)

cat("Matrix product: "); print(m2)

​

# Assignments:

a <- 1

b <<- 2

c = 3

4 -> d

5 ->> e

​