Vector operations in R

gistfile1.txt

# VECTOR OPERATIONS IN R

# Create vectors
age <- c(28, 19, 29, 81, 60, 55, 44, 23)
year <- 1990:1995 # notice the use of : operator for sequence function (seq)
five.ones <- rep(1, 5) # checkout the use of repeat function

# a vector of odd numbers between 1 and 100
odd.numbers <- seq(1, 100, by=2)
?seq

# ----------------------------------

# Accessing elements of vector

# get one element
age[2]

# get multiple elements (subset)
odd.numbers[1:20]
odd.numbers[c(1,10,20)]

# get elements that pass a test
age[age > 55]

# ----------------------------------

# Vector properties

# length
length(odd.numbers)

# summary stats
summary(age)

# structure
str(age)

# ----------------------------------

# Manipulate vector

# set value
age[2] <- 99

# reverse vector
rev(age)

# sort
sort(age)

# reverse sort
sort(age, decreasing=T)

# apply math functions
age * 2
year + 2

# ----------------------------------

# Apply stats functions to vector
# max
max(age)

# min
min(age)

# mean
mean(age)

# median
median(age)

# sum
sum(age)

# variance
var(age)

# rank
rank(age)

# ----------------------------------

# Test for vector
is.vector(age)