Utility function to find and display R documentation.
RShowDoc(what, type = c("pdf", "html", "txt"), package)
a character string: see ‘Details’.
an optional character string giving the preferred format.
Can be abbreviated.
an optional character string specifying the name of a
package within which to look for documentation.
A invisible character string given the path to the file found.
what can specify one of several different sources of documentation,
including the R manuals (R-admin, R-data, R-exts,
R-intro, R-ints, R-lang), NEWS,
COPYING (the GPL licence), any of the licenses in
share/licenses, FAQ (also available as
R-FAQ), and the files in R_HOME/doc.
Only on Windows, the R for Windows FAQ is specified by rw-FAQ.
If package is supplied, documentation is looked for in the
doc and top-level directories of an installed package of that name.
If what is missing a brief usage message is printed.
The documentation types are tried in turn starting with the first
specified in type (or "pdf" if none is specified).