Re: Problem in
Javin Paul <[email protected]> Sat, 18 May 2019 11:13:31 +0800
| Newsgroups | gmane.comp.db.postgresql.sql |
|---|---|
| Message-ID | <CAKGadqYnnvkiiR5cJXxJW1_3=sbr-g2xy455FA=XMDMr86We_A@mail.gmail.com> |
Hello All, I want to unsubscribe from this group, can anyone please guide? Sorry for the trouble. Regards Javin On Fri, Apr 26, 2019 at 3:24 PM Max Lipsky <[email protected]> wrote: > Hello Tom! > > I think is too much for roundoff error > > Found funny post about it: > > https://randomascii.wordpress.com/2014/10/09/intel-underestimates-error-bounds-by-1-3-quintillion/ > http://notabs.org/fpuaccuracy/index.htm > > > > On 25 Apr 2019, at 19:56, Tom Lane <[email protected]> wrote: > > Max Lipsky <[email protected]> writes: > > SELECT acos( > cos(radians(48.9193)) > * cos(radians(48.9193)) > * cos(radians(2.5431) - radians(2.5431)) > + sin(radians(48.9193)) > * sin(radians(48.9193)) > ) as result; > > > This returned [22003] ERROR: input is out of range > > > Not too surprising, because (at least on my machine) > > regression=# select cos(radians(48.9193)) > regression-# * cos(radians(48.9193)) + sin(radians(48.9193)) > regression-# * sin(radians(48.9193)); > ?column? > -------------------- > 1.0000000000000002 > (1 row) > > Problems of this sort are inevitable when working with finite-precision > math. > > https://en.wikipedia.org/wiki/Round-off_error > > regards, tom lane > > > -- Thanks Javin http://javarevisited.blogspot.com/ Twitter : https://twitter.com/javinpaul blog : http://java67.blogspot.com blog : http://savingsfunda.blogspot.com