### Getting Started With R

R is both a programming language and software environment for statistical computing, which is free and open-source. To get started, you will need to install two pieces of software:

- R, the actual programming language. – Chose your operating system, and select the most recent version. Read how to install R in Windows system from
**here**. - RStudio, an excellent IDE for working with R. – Note, you must have R installed to use RStudio. RStudio is simply an interface used to interact with R. Learn how to install RStudio from here.

Once your R environment is ready to install a package, use the install.packages() function.

Suppose “ggplot2” is a package used for visualization. And you want to install “ggplot2” in your R environment then write install.packages(“ggplot2”).

#Install ggplot2 packge

`install.packages("ggplot2")`

Once a package is installed, it must be loaded into your current R session before being used.

#Load the ggplot2 package

library(ggplot2)

To get started, we’ll use R like a simple mathematical tool. We will show how to do basic calculation in R.

**Basic Calculations:**

**Addition:**

#Addition

a<-3

b<-5

c<- a+b

print(c)

**Output:**

##[1] 8

**Subtraction:**

a<-10

b<-5

c<- a-b

print(c)

**Output:**

[1] 5

**Multiplication:**

a<-10

b<-5

c<- a*b

print(c)

**Output:**

[1] 50

**Division:**

a<-10

b<-5

c<- a/b

print(c)

**Output:**

[1] 2

**Exponents:**

a<-9

b<-2

c<- a^b

d<- a^(-b)

e<- a^(1/2)

s<- sqrt(a)

print(c)

print(d)

print(e)

print(s)

**Output:**

> print(c)

[1] 81

> print(d)

[1] 0.01234568

> print(e)

[1] 3

> print(s)

[1] 3

>

**Mathematical Constants:**

exp(1) #equivalent to e

pi #equivalent to π

p=pi/3

print(p)

e=exp(1)^0

print(e)

**Output:**

> exp(1) #equivalent to e

[1] 2.718282

> pi #equivalent to π

[1] 3.141593

> p=pi/3

> print(p)

[1] 1.047198

> e=exp(1)^0

> print(e)

[1] 1

**Logarithms:**

log(exp(1)) #equivalent log(e)

log10(1000) #equivalent to log10(1000)

log2(16) #equivalent to log2(8)

log(16, base = 4)#equivalent to log4 (16)

**Output:**

> log(exp(1)) #equivalent log(e)

[1] 1

> log10(1000) #equivalent to log10(1000)

[1] 3

> log2(16) #equivalent to log2(8)

[1] 4

> log(16, base = 4)#equivalent to log4 (16)

[1] 2

**Trigonometry:**

s<-sin(pi / 2) #equivalent to sin(π/2)

c<- cos(0) # equivalent to cos(0)

print(s)

print(c)

**Output:**

> s<-sin(pi / 2) #equivalent to sin(π/2)

> c<- cos(0) # equivalent to cos(0)

> print(s)

[1] 1

> print(c)

[1] 1

#### Getting Help in R:

In using R as a calculator, we have seen a number of functions: sqrt(), exp(), log() and sin(). To get documentation about a function in R, simply put a question mark in front of the function name and RStudio will display the documentation, for example:

?log

?sin

?cos