PROGRAMMING IN R

Introduction to R

Introduction to R

In this session I will:•Introduce you to the R program and windows•Show how to install R •Write basic programs in R

Introduction to R

• R is available at the following website:http://www.r-project.org/

• You can download R by clicking on the “Down Load” link.

• We will demonstrate this later in this video.

Introduction to R

• There is an introduction to R available on the CRAN R-project website.

http://cran.r-project.org/doc/manuals/R-intro.pdf• I recommend downloading this

document and getting acquainted with it.

Introduction to R

•R is an environment for statistical computing, data analysis, and graphics•We will use R for describing and analyzing data•Being proficient in using R for statistical computing and analysis a skill that is highly valued in multiple arenas

R Environment

• R is an extremely capable environment.• The differences between R and SAS are too enumerable to describe. •R is similar to the S language developed at Bell Laboratories. •R can be challenging to learn but practice will make it easier.

R Environment

• There are three basic components to the R environment or R console.

• R Commands window or Prompt– executes the commands.

• Script Window – a program editor provided by R.

• Graphics Window – an output window that displays graphics.

R Environment

• R is an expression language• It is case sensitive

– A and a are two different symbols– Refer to different variables.

• Elementary commands consist of either expressions or assignments.

R Environment

• Expressions– Given as a command, is evaluated,

printed, and the value is lost.• Assignments

– Evaluates the expression and passes the value to a variable

– The result is not printed.

R Environment

• The R environment also has many different ways to store data.

• R is an object oriented language so everything is stored as an object.

• In this session, we will define the various types of objects but we will only use 2 of these types.

R variables.

• There are different types of objects or ways to store variables.

• Vectors• Lists• Functions• For now, we will only work with

Vectors.

Introduction to R

• Let’s install R.