from the credit where credit is due department: Arb (available with Nemo.jl) is better.
On Saturday, October 17, 2015 at 7:43:02 PM UTC-4, John Gibson wrote: > > I have to take back a couple things. The Julia docs are clearer than I > thought about the BigFloat type: it's fixed-sized but arbitrarily large, > with size resettable by a function call. Second, > > julia> eps(BigFloat) > > 1.727233711018888925077270372560079914223200072887256277004740694033718360632485e-77 > > so an 1e-77 error in sin(BigFloat(pi)) is just what you'd expect. I'll > have to read up on how many bits the type gets by default, how many are in > the mantissa, how many in the exponent, and why the string rep gives three > more digits than epsilon. And I think I understand your motivation for the > double-double type, if not the Float125 and Float127 names. Tom, thanks for > the pointer to Unum --it looks very interesting. > > John > > > > On Saturday, October 17, 2015 at 4:56:20 PM UTC-4, Jeffrey Sarnoff wrote: >> >> I have re-implemented a number of them. The better double-double >> libraries are very good +,-,*,^, exp, slightly less so with /; I found some >> trig lsbs to be wiggly. >> >> I mapped triple-double basics and quad-double algorithms into a triplet >> cooperative, used internally to assure the manifold smoothness. >> >> On Saturday, October 17, 2015 at 4:41:44 PM UTC-4, Jeffrey Sarnoff wrote: >>> >>> I have been -- this has taken up much of the past month. The better >>> double-double libraries are very good +,-,*,^, exp, slightly less so with >>> /; I found some trig lsbs to be wiggly. >>> >>> I hand down-converted some quad-double algorithms and routines to be >>> triple-double work-alikes. I use them internally to obtain an exported type >>> that is numerically smoother. >>> >>> >>> On Saturday, October 17, 2015 at 4:12:44 PM UTC-4, Steven G. Johnson >>> wrote: >>>> >>>> >>>> >>>> On Saturday, October 17, 2015 at 9:39:54 AM UTC-4, Jeffrey Sarnoff >>>> wrote: >>>>> >>>>> I am working on routines for a double-double-like floating point type. >>>>>> >>>>>> >>>> There are plenty of such libraries already existing as free/open-source >>>> software. Why not crib from them? >>>> >>>
