In Windows Operating system, The *R* installer will have created an icon for *R* on desktop and a Start Menu item. Double click the *R* icon to start the *R* Program; *R* will open the console, to type the *R* commands.

The greater than sing (>) in console is the prompt symbol. In this tutorial we will use *R* language as calculator (we will be Using R as Calculator for mathematical expressions), by typing some simple mathematical expressions at the prompt (>). Anything that can be computed on a pocket calculator can also be computed at the *R* prompt. After entering the expression on prompt, you have to press the Enter key from keyboard to execute the command. Some examples using R as calculator are as follows

> 1 + 2 #add two or more numbers

> 1 – 2 #abstracts two or more numbers

> 1 * 2 #multiply two or more numbers

> 1 / 2 #divides two more more numbers

> 1%/ %2 #gives the integer part of the quotient

> 2 ^ 1 #gives exponentiation

> 31 %% 7 #gives the remainder after division

These operators also works fine for complex numbers.

Upon pressing the enter key, the result of expression will appear, prefixed by a number in square bracket:

> 1 + 2

[1] 54

The [1] indicates that this is the first result from the command.

Some advance calculations that are available in scientific calculators can also be easily done in *R* for example

> sqrt(5) #Square Root of a number

> log(10) #Natural log of a number

> sin(45) #Trignometric function (sin function)

> pi #*pi* value 3.141593

> exp(2) #Antilog, *e* raised to a power

> log10(5) #Log of a number base 10

> factorial(5) #Factorial of a number e.g 5!

> abs(1/-2) #Absolute values of a number

> 2*pi/360 #Number of radian in one Babylonian degree of a circle

Remember *R* prints all very large or very small numbers in scientific notation.

*R* language also make use of parentheses for grouping operations to follow the rules for order of operations. for example

> 1-2/3 #It first computes 2/3 and then subtract it from 1

> (1-2)/3 #It first computes (1-2) and then divide it by 3

*R* recognizes certain goofs, like trying to divide by zero, missing values in data etc.

> 1/0 #Undefined, R tells it a infinity (Inf)

> 0/0 #Not a number (NaN)

> “one”/2 #Strings or character is divided by a number

**Download pdf file:
****R Language as Calculator 53.52 KB**

**R Language as Calculator 53.52 KB**

**Further Reading:** http://en.wikibooks.org/wiki/Statistical_Analysis:_an_Introduction_using_R/R/R_as_a_calculator