BOL

R is a functional based language, the inputs to a function, including options, are in brackets. Note that all dat and options are separated by a comma

• Function(data, options)

Even quit is a function

• q()

So is help

help(read.table)

Provides the help page for the FUNCTION ‘read.table’

help.search(“t test”)

Searches for help pages that might relate to the phrase ‘t test’

NOTE: quotes are needed for search strings, they are not needed when referring to data objects or function names.

There is a short cut for help,

? shows the help page on a function name, same as help(function)

?read.table

?? searches for help pages on functions, same as help.search(‘phrase’)

??“t test”

Information is usually returned from a function, by default this is printed to screen

read.table(‘data.tsv’) or read.table(‘http://bioinformatics.knowledgeblog.org/wp-content/uploads/bioinf/kerr/data.tsv’)

This can always be stored, we call what it is stored in an ‘object’

mydata <- read.table(‘data.tsv’)

here mydata is an object of type dataframe

Reminder:

• Vector: a list of numbers, equivalent to a column in a table
• Data Frame = a collection of vectors. Equivalent to a table

Hint:

• Up/Down arrow keys can be use to cycle through previous commands