Re: [Caml-list] Are you sure the new "=" of 3.08 is good ?

[David Brown <caml-list@davidb.org>]

On Fri, Oct 08, 2004 at 07:49:17AM +0200, Christophe Raffalli wrote:
> 
> >You can perfectly well compute it, and the general consensus among the
> >floating-point community is that trig functions should do the best they
> >reasonably can even on huge arguments. Techniques for doing this kind
> >of reduction reasonably efficiently have been known for at least 20
> >years, e.g.
> 
> Yes you can perfectly compute sin 10e100.
> 
> But if x is the result of any computation (with rounding error), and x 
> is huge, sin x may be any value between -1 and 1. So the best value from 
> sin x is either 0 (your possible error is minimum) or nan.

sin 10e100 (1e101) isn't meaningful with any kind of floating point
precision I'm aware of.  Any numerical process that is attempting to take
the sin of a value like this has long since lost any meaningful digits out
of the number.

Dave

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