Help command you need in R language

Help command in R-Language

R has an inbuilt help facility similar to the man facility of UNIX. To get more information on any specific named function, for example solve, the command is

> help(solve)

An alternative is
> ?solve

For a feature specified by special characters, the argument must be enclosed in double or single quotes, making it a “character string”: This is also necessary for a few words with syntactic meaning including if, for and function.
> help("[[")

Either form of quote mark may be used to escape the other, as in the string "It’s important". Our convention is to use double quote marks for preference. On most R installations help is available in HTML format by running
> help.start()

which will launch a Web browser that allows the help pages to be browsed with hyperlinks. On UNIX, subsequent help requests are sent to the HTML-based help system. The ‘Search Engine and Keywords’ link in the page loaded by help.start() is particularly useful as it is contains a high-level concept list which searches though available functions. It can be a great way to get your bearings quickly and to understand the breadth of what R has to offer.

The help.search command (alternatively ??) allows searching for help in various ways. For
example,
> ??solve

Try ?help.search for details and more examples.
The examples on a help topic can normally be run by
> example(topic)

Windows versions of R have other optional help systems: use
> ?help