Avishalom Shalit wrote: > well.... > matlab can use variable precision (not automatically though) , so > technically , you can accurately represent the number (1e300+1e-300)
Perl has various high precision floating point modules listed on CPAN: Math::MPFR Math::BigFloat Math::GMPf > on a side note, if you ever need to, you are probably doing it wrong. > > e.g. 1 - if you are multiplying probabilities , e.g. for a generative > statistical model, > and are approaching underflow, > work with the LOGs and you'll be doing just fine on doubles. > e.g. 2 - if your numerical ODE solvers aren't converging right, check > your algorithm , precision isn't likely to help you much anyway. > > > ---- > the only reason i had ever wanted variable precision was e.g. to > calculate pi or e as an exercise using one of the canon formulae > > -- vish > > > 2009/11/9 Craig DeForest <[email protected] > <mailto:[email protected]>> > > PDL has the same precision at Matlab -- they both use double-precision > IEEE floating point (on all the usual platforms). > > On Nov 9, 2009, at 7:11 AM, Gabor Szabo wrote: > > > I don't recall I ever had to deal with numbers in perl that were too > > big or too small for perl but I guess with real engineering stuff > > people will need very good precision and very big numbers. > > > > In the Matlab tutorial I see it has 16 significant decimal digits in > > floating point and > > a range of 10**-308 and 10**308. > > > > What can we say about Perl or PDL in this regard? > > How can we deal with cases when really good precision > > is required? > > > > Gabor > > > > _______________________________________________ > > Perldl mailing list > > [email protected] <mailto:[email protected]> > > http://mailman.jach.hawaii.edu/mailman/listinfo/perldl > > > > > _______________________________________________ > Perldl mailing list > [email protected] <mailto:[email protected]> > http://mailman.jach.hawaii.edu/mailman/listinfo/perldl > > > > ------------------------------------------------------------------------ > > _______________________________________________ > Perldl mailing list > [email protected] > http://mailman.jach.hawaii.edu/mailman/listinfo/perldl > > > ------------------------------------------------------------------------ > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 8.5.425 / Virus Database: 270.14.55/2489 - Release Date: 11/08/09 > 07:37:00 > _______________________________________________ Perldl mailing list [email protected] http://mailman.jach.hawaii.edu/mailman/listinfo/perldl
