| example | R Documentation |
Run all the R code from the Examples part of R's online help
topic topic with possible exceptions dontrun,
dontshow, and donttest, see ‘Details’ below.
example(topic, package = NULL, lib.loc = NULL,
character.only = FALSE, give.lines = FALSE, local = FALSE,
echo = TRUE, verbose = getOption("verbose"),
setRNG = FALSE, ask = getOption("example.ask"),
prompt.prefix = abbreviate(topic, 6),
run.dontrun = FALSE, run.donttest = interactive())
topic |
name or literal character string: the online
|
package |
a character vector giving the package names to look
into for the topic, or |
lib.loc |
a character vector of directory names of R libraries,
or |
character.only |
a logical indicating whether |
give.lines |
logical: if true, the lines of the example source code are returned as a character vector. |
local |
logical: if |
echo |
logical; if |
verbose |
logical; if |
setRNG |
logical or expression; if not |
ask |
logical (or |
prompt.prefix |
character; prefixes the prompt to be used if
|
run.dontrun |
logical indicating that |
run.donttest |
logical indicating that |
If lib.loc is not specified, the packages are searched for
amongst those already loaded, then in the libraries given by
.libPaths(). If lib.loc is specified, packages
are searched for only in the specified libraries, even if they are
already loaded from another library. The search stops at the first
package found that has help on the topic.
An attempt is made to load the package before running the examples, but this will not replace a package loaded from another location.
If local = TRUE objects are not created in the workspace and so
not available for examination after example completes: on the
other hand they cannot overwrite objects of the same name in the
workspace.
As detailed in the manual Writing R Extensions, the author of the help page can markup parts of the examples for exception rules
dontrunencloses code that should not be run.
dontshowencloses code that is invisible on help
pages, but will be run both by the package checking tools,
and the example() function. This was previously
testonly, and that form is still accepted.
donttestencloses code that typically should be run,
but not during package checking. The default
run.donttest = interactive()
leads example() use in other help
page examples to skip \donttest sections appropriately.
The value of the last evaluated expression, unless give.lines
is true, where a character vector is returned.
Martin Maechler and others
demo
example(InsectSprays)
## force use of the standard package 'stats':
example("smooth", package = "stats", lib.loc = .Library)
## set RNG *before* example as when R CMD check is run:
r1 <- example(quantile, setRNG = TRUE)
x1 <- rnorm(1)
u <- runif(1)
## identical random numbers
r2 <- example(quantile, setRNG = TRUE)
x2 <- rnorm(1)
stopifnot(identical(r1, r2))
## but x1 and x2 differ since the RNG state from before example()
## differs and is restored!
x1; x2
## Exploring examples code:
## How large are the examples of "lm...()" functions?
lmex <- sapply(apropos("^lm", mode = "function"),
example, character.only = TRUE, give.lines = TRUE)
sapply(lmex, length)
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.
