[R] Link from vignette to package documentation

[Martin Maechler]

>>>>> Duncan Murdoch 
>>>>>     on Fri, 21 Sep 2018 05:02:32 -0400 writes:

    > On 21/09/2018 4:54 AM, Sigbert Klinke wrote:
    >> Hi,
    >> 
    >> is it possible to make a link from a vignette to a (Rd)
    >> help files in my own or other packages?

    > Only with some significant compromises.  R normally acts
    > as the web server for Rd files, and the URL is not really
    > predictable.  So you would need to make the URL
    > predictable, either by something like

    > options(help.ports = 12345)

    > (which will put help on port 12345, blocking that port for
    > any other use, including help in another R session), or by
    > putting a static copy of the help pages on some other web
    > server.

    > Duncan Murdoch

Yes, and the other way around -- making working links from
package (*.Rmd or *.Rnw) vignettes to help pages of the same
package is also not easily and portably possible AFAICS.

Both would be desirable quite desirable for improved R
documentation and ideally so in a way that could also work with
an internet connection.

[and if we continue this, it may become more of an issue for
'R-devel' instead of 'R-help' ...]

Martin Maechler