R devel - Jan 2015 - Reimplement stats:::plotNode as iterative to avoid recursion limits?

Hi All,

I've gotten a number of reports from users about gplots::heatmap.2
generating 'node stack overflow' errors.  As it turns out, these errors
originate in stats:::plotNode, and are triggered when it is passed a dendrogram
that is too deeply nested.

While increasing the stack size (which is a compile-time option for byte coded
functions) can allow a particular instance to succeed, a better solution would
be to modify stats:::plotNode to use a recursive, rather than iterative
algorithm.

Anyone want to take this up as a programming challenge?   

-Greg

>>>>> Gregory R Warnes <greg at warnes.net>
>>>>>     on Thu, 1 Jan 2015 18:35:23 -0500 writes:
    > Hi All, I've gotten a number of reports from users
    > about gplots::heatmap.2 generating 'node stack
    > overflow' errors.  As it turns out, these errors
    > originate in stats:::plotNode, and are triggered when
    > it is passed a dendrogram that is too deeply nested.

    > While increasing the stack size (which is a
    > compile-time option for byte coded functions) can
    > allow a particular instance to succeed, a better
    > solution would be to modify stats:::plotNode to use a
    > recursive, rather than iterative algorithm.

of course you mean the contrary: reprogram stats:::plotNode() to
use a *non*-recursive algorithm {"iterative" as you say in the
'Subject' line}

    > Anyone want to take this up as a programming
    > challenge?

Yes, please,  patches are very welcome -- if they are tested.

Please start from
       https://svn.r-project.org/R/trunk/src/library/stats/R/dendrogram.R
i.e. send patches with respect to that,
i.e., the result of
      diff -ubBw <old-dendrogram>.R <new-dendrogram>.R

With thanks in advance,
Martin Maechler