[R] Demo files in R packages

[Michael L Friendly]

I know I can put them into a vignette, but the advantage of demo files is that you can run them using demo().
It just seems like the facilities for demo files were abandoned.

-Michael



-----Original Message-----
From: Duncan Murdoch <murdoch.duncan using gmail.com> 
Sent: January 24, 2026 6:02 PM
To: Michael L Friendly <friendly using yorku.ca>; R-help using r-project.org
Subject: Re: [R] Demo files in R packages

On 2026-01-24 4:49 p.m., Michael L Friendly wrote:
> Before vignettes were established as a way to document a package, there were demos, R files in a `demo/` folder with a `demo/00-Index` file giving their contents.
> Used as `demo(package="...")` this gave a window with a list and titles, and `demo("example1", package="...") ran `demo/example1.R` in the console.
> It was also a good way to give a pointer to something more extensive than you wanted to include in the examples for a function or dataset.
> 
> This idea still works for R packages, but is not available for use in roxygen2 documentation, or pkgdown sites.
> I have several packages with collections of demo/ files, and am wondering if there is anything further I can do with them to make them accessible.

I converted most of my demo files in rgl to a single vignette.  I just added a simple paragraph

> This vignette holds code that was previously included as "demos" 
> in `rgl`.  Some of the demos require R to be running; those remain 
> available via `demo(package = "rgl")`.

As the second sentence indicates, rgl still has a few demos, mostly Shiny examples.

Conversion was simple:  just copy the title into a heading, and include all the code.

Duncan Murdoch