Hi all, >From what I can see from my checkout of the Rsources (in src/main/summary.c as pointed out by others) sums are calculated the "naive" way (see rsum c function) but means are actually calculated something akin to the Neumaier way (see real_mean c function).
Just an fyi. ~G On Thu, Feb 21, 2019 at 9:03 AM Ben Bolker <bbol...@gmail.com> wrote: > Specifically: https://svn.r-project.org/R/trunk/src/main/summary.c > > And if you don't want to deal with Subversion, you can look at the > read-only github mirror: > > > https://github.com/wch/r-source/blob/e5b21d0397c607883ff25cca379687b86933d730/src/main/summary.c#L115-L131 > > On Thu, Feb 21, 2019 at 11:57 AM David Winsemius <dwinsem...@comcast.net> > wrote: > > > > > > On 2/20/19 2:55 PM, Rampal Etienne wrote: > > > Dear Tomas, > > > > > > Where do I find these files? Do they contain the code for the sum > function? > > > > Yes. > > > > https://svn.r-project.org/R/trunk/ > > > > > > David > > > > > > > > What do you mean exactly with your point on long doubles? Where can I > find > > > documentation on this? > > > > > > Cheers, Rampal > > > > > > On Mon, Feb 18, 2019, 15:38 Tomas Kalibera <tomas.kalib...@gmail.com > wrote: > > > > > >> See do_summary() in summary.c, rsum() for doubles. R uses long double > > >> type as accumulator on systems where available. > > >> > > >> Best, > > >> Tomas > > >> > > >> On 2/14/19 2:08 PM, Rampal Etienne wrote: > > >>> Hello, > > >>> > > >>> I am trying to write FORTRAN code to do the same as some R code I > > >>> have. I get (small) differences when using the sum function in R. I > > >>> know there are numerical routines to improve precision, but I have > not > > >>> been able to figure out what algorithm R is using. Does anyone know > > >>> this? Or where can I find the code for the sum function? > > >>> > > >>> Regards, > > >>> > > >>> Rampal Etienne > > >>> > > >>> ______________________________________________ > > >>> R-devel@r-project.org mailing list > > >>> https://stat.ethz.ch/mailman/listinfo/r-devel > > >> > > >> > > > [[alternative HTML version deleted]] > > > > > > ______________________________________________ > > > R-devel@r-project.org mailing list > > > https://stat.ethz.ch/mailman/listinfo/r-devel > > > > ______________________________________________ > > R-devel@r-project.org mailing list > > https://stat.ethz.ch/mailman/listinfo/r-devel > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel > [[alternative HTML version deleted]] ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
