[Octave-bug-tracker] [bug #48307] sinc loses precision for large arguments

[Colin Macdonald]

Follow-up Comment #14, bug #48307 (project octave):

Sorry for speaking imprecisely.  Glibc's sin is a backwards stable algorithm:
we got the exact answer of a nearby problem, measured relatively.

We don't have the exact x, so we don't expect the exact answer.
But we hope for a good answer in the backward error sense: the answer we get
(5.62e-10) is the exact answer of sin(x+delta) where delta is small in a
relative sense to 10000000*pi.  This is what I take home from the example in
Comment #8 and #5.



    _______________________________________________________

Reply to this item at:

  <http://savannah.gnu.org/bugs/?48307>

_______________________________________________
  Message sent via/by Savannah
  http://savannah.gnu.org/