Example R programs and commands
1. Data lists; mean and median
# All lines preceded by the "#" character are my comments.
# All other left-justified lines are my input.
# All other indented lines are the R program output.
# To enter a list of data into a variable named "x"
x <- c(1.1, 2.0, 1.5, 2.1, 1.9, 1.8)
# NOTE: "<-" means assignment; read it as "gets". "=" can be used as well.
# To display the value of "x"
x
[1] 1.1 2.0 1.5 2.1 1.9 1.8
# Number of elements in the list named "x"
length(x)
[1] 6
# Sum of all elements in "x"
sum(x)
[1] 10.4
# Arithmetic mean
mean(x)
[1] 1.733333
sum(x)/length(x)
[1] 1.733333
# Proportional median
median(x)
[1] 1.85
# Concatenate two lists
y <- c(3.5, 3.6, 3.7); c(x,y) # semicolons separate commands
[1] 1.1 2.0 1.5 2.1 1.9 1.8 3.5 3.6 3.7
z <- c(x,y); z
[1] 1.1 2.0 1.5 2.1 1.9 1.8 3.5 3.6 3.7