Re: WIP: rewrite numeric division - Mailing list pgsql-patches

From Gregory Stark
Subject Re: WIP: rewrite numeric division
Date
Msg-id 87sl8o8bya.fsf@oxford.xeocode.com
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In response to Re: WIP: rewrite numeric division  (Gregory Stark <stark@enterprisedb.com>)
List pgsql-patches
"Gregory Stark" <stark@enterprisedb.com> writes:

> So your complaint about the existing code boils down to not having any
> rigorous way to know when to stop. I don't think Newton's method has that
> problem, at least not for simple polynomials. Any digits which don't change
> from one iteration to the next are definitely correct.

Er, I don't think that last sentence is correct. But I believe it is possible
to tell how many digits are accurate based on the difference between
successive estimates because you know how fast it converges (quadratically).

--
  Gregory Stark
  EnterpriseDB          http://www.enterprisedb.com


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