[Rd] R-devel on FreeBSD: new C99 functions don't build

[Rainer Hurling]

On 15.05.2012 20:49 (UTC+1), Murray Stokely wrote:
> On Tue, May 15, 2012 at 10:05 AM, Rainer Hurling<rhurlin at gwdg.de>  wrote:
>> About April 25th, there had been some changes within R-devel's
>> src/nmath/pnbeta.c (and probably some other relevant places) and now
>> building R-devel on FreeBSD 10.0-CURRENT (amd64) with gcc-4.6.4 and
>> math/R-devel (selfmade forked port from math/R) fails like this:
>
>> It seems, that at least one new C99 function (log1pl) is introduced in
>> R-devel, see
>>
>> src/nmath/pnbeta.c:l95
>> return (double) (log_p ? log1pl(-ans) : (1 - ans));
>
> AFAIK, Bruce Evans is not happy with the numerical accuracy of other
> open-source implementations of log1pl and so has blocked their
> inclusion in FreeBSD pending work on a better implementation.
>
> Can you put a conditional FreeBSD check here and use log1p instead of
> log1pl instead as a workaround?
>
> I can admire the insistence on correctness from the FreeBSD libm
> maintainers for their technical purity, but it can be a bit of a pain
> for things like this.
>
>           - Murray

I read about this discussion and in principle I concur with your 
opinion. As a scientist I tend to expect greatest possible correctness 
from a statistical routine, especially when it uses long double format.

As a quick and dirty workaround I applied the following patch:


--- src/nmath/pnbeta.c.orig     2012-04-25 17:55:14.000000000 +0200
+++ src/nmath/pnbeta.c  2012-05-15 20:58:26.000000000 +0200
@@ -92,7 +92,11 @@
      else {
         if(ans > 1 - 1e-10) ML_ERROR(ME_PRECISION, "pnbeta");
         if (ans > 1.0) ans = 1.0;  /* Precaution */
+#if !defined(__FreeBSD__)
         return (double) (log_p ? log1pl(-ans) : (1 - ans));
+#else
+        return (double) (log_p ? log1p(-ans) : (1 - ans));
+#endif /* FreeBSD */
      }
  }


It builds and installs fine now and I hope there are no side effects ...

Thank you for the quick answer and your advice,
Rainer