On Sat, Oct 21, 2006 at 11:04:13AM +0200, Patrick Giraudoux wrote:
> Which means that actually sum(x) is NOT considered equal to 1...
> 
> Any idea about what is going wrong?

Others have already pointed out the problem and I would like to add a
reference to a classical paper on this topic:

David Goldberg
What Every Computer Scientist Should Know About Floating-Point Arithmetic
Computing Surveys, 1991

Reprints can be found in many places online - e.g. here:

http://www.physics.ohio-state.edu/~dws/grouplinks/floating_point_math.pdf

cu
        Philipp

-- 
Dr. Philipp Pagel                            Tel.  +49-8161-71 2131
Dept. of Genome Oriented Bioinformatics      Fax.  +49-8161-71 2186
Technical University of Munich
Science Center Weihenstephan
85350 Freising, Germany

 and

Institute for Bioinformatics / MIPS          Tel.  +49-89-3187 3675
GSF - National Research Center               Fax.  +49-89-3187 3585
      for Environment and Health
Ingolstädter Landstrasse 1
85764 Neuherberg, Germany
http://mips.gsf.de/staff/pagel

______________________________________________
R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

Reply via email to