demo
Demonstrations of R Functionality
demo
is a user-friendly interface to running some demonstration
R scripts. demo()
gives the list of available topics.
- Keywords
- utilities, documentation
Usage
demo(topic, package = NULL, lib.loc = NULL,
character.only = FALSE, verbose = getOption("verbose"),
echo = TRUE, ask = getOption("demo.ask"),
encoding = getOption("encoding"))
Arguments
- topic
the topic which should be demonstrated, given as a name or literal character string, or a character string, depending on whether
character.only
isFALSE
(default) orTRUE
. If omitted, the list of available topics is displayed.- package
a character vector giving the packages to look into for demos, or
NULL
. By default, all packages in the search path are used.- lib.loc
a character vector of directory names of R libraries, or
NULL
. The default value ofNULL
corresponds to all libraries currently known. If the default is used, the loaded packages are searched before the libraries.- character.only
logical; if
TRUE
, usetopic
as character string.- verbose
a logical. If
TRUE
, additional diagnostics are printed.- echo
a logical. If
TRUE
, show the R input when sourcing.- ask
a logical (or
"default"
) indicating ifdevAskNewPage(ask = TRUE)
should be called before graphical output happens from the demo code. The value"default"
(the factory-fresh default) means to ask ifecho == TRUE
and the graphics device appears to be interactive. This parameter applies both to any currently opened device and to any devices opened by the demo code. If this is evaluated toTRUE
and the session is interactive, the user is asked to press RETURN to start.- encoding
See
source
. If the package has a declared encoding, that takes preference.
Details
If no topics are given, demo
lists the available demos. The
corresponding information is returned in an object of class
"packageIQR"
.
See Also
source
and devAskNewPage
which
are called by demo
.
Examples
library(utils)
# NOT RUN {
demo() # for attached packages
## All available demos:
demo(package = .packages(all.available = TRUE))
# }
# NOT RUN {
## Display a demo, pausing between pages
demo(lm.glm, package = "stats", ask = TRUE)
## Display it without pausing
demo(lm.glm, package = "stats", ask = FALSE)
# }
# NOT RUN {
# }
# NOT RUN {
ch <- "scoping"
demo(ch, character = TRUE)
# }
# NOT RUN {
## Find the location of a demo
system.file("demo", "lm.glm.R", package = "stats")
# }