Basic Statistics and Data Analysis

Lecture notes, MCQS of Statistics

Using R as Calculator

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:

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

 

The Author

Muhammad Imdadullah

Student and Instructor of Statistics and business mathematics. Currently Ph.D. Scholar (Statistics), Bahauddin Zakariya University Multan. Like Applied Statistics and Mathematics and Statistical Computing. Statistical and Mathematical software used are: SAS, STATA, GRETL, EVIEWS, R, SPSS, VBA in MS-Excel. Like to use type-setting LaTeX for composing Articles, thesis etc.

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