demo {utils} | R Documentation

## Demonstrations of R Functionality

### Description

`demo` is a user-friendly interface to running some demonstration R scripts. `demo()` gives the list of available topics.

### 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` is `FALSE` (default) or `TRUE`. 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 of `NULL` corresponds to all libraries currently known. If the default is used, the loaded packages are searched before the libraries.
`character.only` | logical; if `TRUE`, use `topic` 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 if `devAskNewPage(ask = TRUE)` should be called before graphical output happens from the demo code. The value `"default"` (the factory-fresh default) means to ask if `echo == 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 to `TRUE` 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

    demo() # for attached packages

    ## All available demos:
    demo(package = .packages(all.available = TRUE))

    ## 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:
     ch <- "scoping"
     demo(ch, character = TRUE)

    ## End(Not run)

    ## Find the location of a demo
    system.file("demo", "lm.glm.R", package = "stats")

[Package utils version 3.6.1 Index]