Some Simple R commands

PART 1 - BASIC ARITHMETIC OPERATIONS

R can be used as a calculator. The basic arithmetic operators are:

1. Addition (+)

# addition
5+3

## [1] 8

2. Substraction (-)

# Substraction
5-3

## [1] 2

3. Multiplication (*)

# multiplication
5 * 3

## [1] 15

4. Division (/)

# divison
5 / 3

## [1] 1.666667

5. Exponent (^)

# exponentiation
4^2

## [1] 16

6. Remainder of division (%%)

# returns the remainder of the division of 9/2
9 %% 2

## [1] 1

PART 2- BASIC ARITHMATIC FUNCTIONS

Logarithms and Exponentials

# logarithms base 2 of x=10
log2(10) 

## [1] 3.321928

# logaritms base 10 of x=10
log10(10)

## [1] 1

# Exponential of x=10
exp(10) 

## [1] 22026.47

Other mathematical functions

# absolute value of x=-5
abs(-5) 

## [1] 5

# square root of x=16
sqrt(16) 

## [1] 4

ASSIGNING VALUES TO VARIABLES

A variable can be used to store a value. For example, the R code below will store the price in a variable, say “price”:

# price = 7 
price <- 7
# or use this
price = 7

Important Notes

Note that, it’s possible to use <- or = for variable assignments.

Note that, R is case-sensitive. This means that Price is different from price.

It’s possible to make some operations with it.

# multiply Price by 3
3 * price

## [1] 21

You can change the value of the object:

# change the value
price <- 5
# print again
price

## [1] 5

The following R code creates two variables holding the width and the height of a rectangle. These two variables will be used to compute the area of the rectangle.

# height of a rectangle
height <- 10

# width of a rectangle
width <- 5

# area of rectangle
area <- height*width
area

## [1] 50