InfoGuides: Learn R: Concepts

Functions & Packages

Functions

() = Holds Arguments

, = Separates Arguments

Packages

Packages are groups of functions. You can't use a function until it has been both installed and loaded (or else R won't recognize the function name).

Objects & Assignment

Assignment

Create an object (or change the value) by using the arrow pointing toward the name you are giving your object (type a less than sign "<", then a dash "-"). The "type" of your new object will depend on what is on the right of the arrow. To print the contents of your object, just type the name of the object.

<- = Create an Object

> nine <- 9
> nine
[1] 9
> mylist <- c("one", "two")
> mylist
[1] "one" "two"

Object Parts

For objects of type list or dataframe, you can get specific parts of the object using brackets or dollar signs.

[] = Index

> list[ element ]
> dataset[ row, column ]

$ = Column Name

> dataset$column_name

There are 4 basic concepts you need to understand:

Assignment
Objects
Functions
Packages