#### 1. Using ?

?mean opens the help page for the mean function

?"+" opens the help page for addition

?"if" opens the help page for if, used for branching code

#### 2. Using ??

To find functions, type two question marks (??) followed by a keyword related to the problem to search. Special characters, reserved words, and multiword search terms need enclosing in double or single quotes. for example:??plotting searches for topics containing words like "plotting"

??"regression model" searches for topics containing phrases like this

#### 3. help and help.search

The functions help and help.search do the same things as ? and ??, respectively, but with these you always need to enclose your arguments in quotes. The following commands are equivalent to the previous examples:help("mean")help("+")

help("if")

help.search("plotting")

help.search("regression model")

#### 4. example and demo functions

example(plot)

demo() #list all demonstrations

demo(Japanese)

#### 5. vignettes

browseVignettes()

You can also access a specific vignette using the vignette function (but if your memory is as bad as mine, using browseVignettes combined with a page search is easier than trying to remember the name of a vignette and which package it’s in):

vignette("Sweave", package = "utils")

#### 6. RSiteSearch

that you have installed on your machine. If you want to look in any package, you can use RSiteSearch, which runs a query at http://search.r-project.org. Multiword terms need to be wrapped in braces:

RSiteSearch("{Clustering}")