| help {base} | R Documentation |
Documentation
Description
These functions provide access to documentation.
Documentation on a topic with name name (typically, an R
object or a data set) can be printed with either help(name) or
?name.
Usage
help(topic, offline = FALSE, package = .packages()
lib.loc = .lib.loc, verbose = getOption("verbose"),
htmlhelp = getOption("htmlhelp"))
?topic
Arguments
topic |
a name or character string on which documentation is sought (but not a variable containing a character string!). |
offline |
a logical indicating whether documentation should be displayed on-line to the screen (the default) or hardcopy of it should be produced. |
package |
a name or character vector giving the packages to look into for documentation. By default, all packages in the search path are used. |
lib.loc |
A character vector of directory names of R libraries. Defaults to all libraries currently known. |
verbose |
logical; if |
htmlhelp |
logical (or |
Details
In the case of unary and binary operators and control-flow special forms, the name may need to be quoted.
If offline is TRUE, hardcopy of the documentation is
produced by running the LaTeX version of the help page through
latex (note that LaTeX 2e is needed) and dvips.
Depending on your dvips configuration, hardcopy will be sent to
the printer or saved in a file. If the programs are in non-standard
locations and hence were not found at compile time, you can either set
the options latexcmd and dvipscmd, or the environment
variables R_LATEXCMD and R_DVIPSCMD appropriately.
The appearance of the output can be customized through a file
‘Rhelp.cfg’ somewhere in your LaTeX search path.
Note
You will only get help for R objects in your
search() path, i.e., help(dist) will only work after
library(mva). To look in all the packages in all the
current libraries, use
help(topic, package=.packages(all=T), lib.loc=.lib.loc)
The help files can be many small files. On some file systems it is desirable to save space, and the text files in the ‘help’ directory of an installed package can be zipped up as a zip archive ‘Rhelp.zip’. Ensure the files ‘AnIndex’ and ‘00Titles’ remain un-zipped. Similarly, all the files in the ‘latex’ directory can be zipped to ‘Rhelp.zip’.
See Also
help.search() for finding help pages on a “vague” topic.
help.start() which opens the HTML version of the R
Manual;
library() for listing available packages and the
user-level objects they contain;
data() for listing available data sets;
methods().
See prompt() to get a prototype for writing help
pages of private packages.
Examples
help()
help(help) # the same
help(lapply)
?lapply # the same
help("for") # or ?"for", but the quotes are needed
?"+"
help(package = stepfun) # get help even when it's not present
data() # list all available data sets
?women # information about data set "women"
topi <- "women"
## Not run: help(topi) ##--> Error: No documentation for `topi'