R Basic

R is a programming language and software environment for statistical analysis, graphics representation and reporting. R was created by Ross Ihaka and Robert Gentleman at the University of Auckland, New Zealand, and is currently developed by the R Development Core Team. This programming language was named R, based on the first letter of first name of the two R authors (Robert Gentleman and Ross Ihaka)

# My first program in R Programming {this is comments}
myString <- "Hello, World!"
print ( myString)

## [1] "Hello, World!"

# My first program in R Programming

Data Types

you need to use various variables to store various information. Variables are nothing but reserved memory locations to store values. This means that, when you create a variable you reserve some space in memory.

a <- 5
print(a)

## [1] 5

print(class(a))

## [1] "numeric"

b = 6
b

## [1] 6

class(b)

## [1] "numeric"

7->c
c

## [1] 7

class(c)

## [1] "numeric"

# integer
d <- 5L
d

## [1] 5

class(d)

## [1] "integer"

# Character
e = "anoop"
e

## [1] "anoop"

class(e)

## [1] "character"

# Logical
TRUE->f
f

## [1] TRUE

class(f)

## [1] "logical"

a=5
b=5
a+b

## [1] 10

sum(a,b)

## [1] 10

b = 13
a < b 

## [1] TRUE

a > b

## [1] FALSE

a == b

## [1] FALSE

a <= b

## [1] TRUE

a >= b

## [1] FALSE

a*b

## [1] 65

a!=b

## [1] TRUE

c = 7

(a < b) & (a < c)

## [1] TRUE

(a < c) | (a < c)

## [1] TRUE

if(a < 10)
{
  print(" a is lessthan 10 ")
}else{
  print(" a is greater than 10 ")
}  

## [1] " a is lessthan 10 "

a

## [1] 5

b

## [1] 13

if( a< b){
  print(" a is lessthan b")
}else{
  print(" a is greater than b")
}

## [1] " a is lessthan b"

a = 15
if(a<10 & a>0)
{
  print("a is less than 10")
  print(a)
} else if (a>20)
{
  print("a is greater than 20")
  print(a)
}else
  print("a has a value between 10 and 20")

## [1] "a has a value between 10 and 20"

fn = function(x,y)
{
  return(x+y)
}
fn(4,5)

## [1] 9

fn(4,5)->p
p

## [1] 9

b

## [1] 13

print(a, b)#prints the value of a

## [1] 15

paste(2,3)#default seperator is space

## [1] "2 3"

paste(a, b, 5,sep = ",")#the default sep is space

## [1] "15,13,5"

paste(a,b,10,20,100.3,sep = ", ")->var
print(var)

## [1] "15, 13, 10, 20, 100.3"

p=paste(2,3,4,5,6,8, sep = "") #sep = blank to take off the space
print(p)

## [1] "234568"

if(a<10) 
  print(paste("a is less than 10. The value of a is: ", a, sep  = "")) else 
  print(paste("a is greater than 10. The value of a is: ",a, sep = ""))

## [1] "a is greater than 10. The value of a is: 15"

cat func will do the pasting as well as printing

if(a<10) 
  cat("a is less than 10. The value of a is: ", a, sep  = "") else 
  cat("a is greater than 10. The value of a is: ",a, sep = "")

## a is greater than 10. The value of a is: 15

cat(a,b)#puts the default sep of " "

## 15 13

cat(a, b, sep = ", ")

## 15, 13

cat(a,b,sep = "")

## 1513

paste(a,b)->c
c->d
d

## [1] "15 13"

print(a)->e

## [1] 15

e

## [1] 15

paste(a,b)->c
print(c)

## [1] "15 13"

cat(a,b)->c #it returns null 

## 15 13

c

## NULL

#it's only used for pasting and printing