2.1. Packages and help

2.1.1. Install and load packages

Sometimes you need to install packages that contain certain functions. Use the install.packages() command for this purpose:

install.packages('stringi')

Then you can use or load the package with the library() function:

# use the library
library('stringi')

A list of packages can be found on the CRAN (for Comprehensive R Archive Network).

Here is a list of interesting packages:

• JSONLITE to read JSON files
• RMySQL to read data from MySQL database
• XML to read data from XML files
• reshape2 or tidyr to change data row and column formats from "wide" to "long"
• many more here

2.1.2. Help

To get help in R simply use the command help():

# help about a function
help(cor)
 
# get help about package
help(package = "ggplot2")