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