[Rd] I have corrected a dead link in the treering documentation

[Martin Maechler]

>>>>> Thomas Levine <_ at thomaslevine.com>
>>>>>     on Fri, 28 Jul 2017 18:53:16 +0000 writes:

    > The attached patch corrects a dead link in the treering
    > documentation.  The URL in the manual [1] refers to a
    > personal home page belonging to Christine Hallman (user
    > "hallman") on the website of the University of Arizona
    > Laboratory of Tree-Ring Research (LTRR). It seems that the
    > LTRR personal homepages have been moved to a new root
    > directory [2] and that Hallman's webpage is no longer
    > there.

    > I have contacted Dr. Hallman. She confirmed that the LTRR
    > hosting has changed and that she has not set up her
    > website on a new host. Also, I have not managed to find
    > any other photographs of the Methuselah Walk.  So the page
    > on the Wayback Machine [3] is the best option I see for
    > now.

    > Dr. Hallman also told me that she has more photographs of
    > the tree, and she has offered to publish them in order
    > that we may reference more photographs eventually.

Dear Thomas,
thank you very much for your careful work about this.
I'm sorry it took so long before anyone reacted to this - and so
thank you as well for the reminder.

 [..........]
 
The web.archive.org  aka Wayback Machine aka Internet Archive
URL does work and your patch is formally fine.

There may be one small problem:  IIUC, the wayback machine is a
+- private endeavor and really great and phantastic but it does
need (US? tax deductible) donations, https://archive.org/donate/,
to continue thriving.
This makes me hesitate a bit to link to it within the "base R"
documentation.  But that may be wrong -- and I should really use
it to *help* the project ?

    > I found other dead links in the base documentation, but I thought most
    > should be kept for reference, as they were usually links to a
    > publisher's webpage for a particular journal article or book. The link
    > of present interest just provides context about the tree whose rings
    > were measured, so I think it is okay to change the link.

    > [1] http://www.ltrr.arizona.edu/~hallman/sitephotos/meth.html
    > [2] http://www.ltrr.arizona.edu/webhome/
    > [3] https://web.archive.org/web/20110523225828/http://www.ltrr.arizona.edu/~hallman/sitephotos/meth.html

    > ----------------------------------------------------------------------
    > Index: src/library/datasets/man/treering.Rd
    > ===================================================================
    > --- src/library/datasets/man/treering.Rd	(revision 72947)
    > +++ src/library/datasets/man/treering.Rd	(working copy)
    > @@ -32,6 +32,6 @@
    > }
    > \references{
    > For some photos of Methuselah Walk see
    > -  \url{http://www.ltrr.arizona.edu/~hallman/sitephotos/meth.html}
    > +  \url{https://web.archive.org/web/20110523225828/http://www.ltrr.arizona.edu/~hallman/sitephotos/meth.html}
    > }
    > \keyword{datasets}