Re: Numerical instability in extracting base B digits of the fractional

Georgi Guninski on Thu, 22 Feb 2024 08:13:58 +0100

Re: Numerical instability in extracting base B digits of the fractional part of real

To: pari-dev@pari.math.u-bordeaux.fr
Subject: Re: Numerical instability in extracting base B digits of the fractional part of real
From: Georgi Guninski <gguninski@gmail.com>
Date: Thu, 22 Feb 2024 09:13:31 +0200
References: <CAGUWgD9jh04yWKo8gnd=oT8sxt---hQiq65tGc0cM6Mxnk3wdw@mail.gmail.com> <Zc9EKwc0OJ8gF/b6@seventeen> <CAGUWgD9R94BGzucES2RMAkakRr8z0yygJrAm-ontN-uWe0Pn+g@mail.gmail.com> <Zc+InbDj44/YHxrK@seventeen> <CAGUWgD8tZP-8T1jStNjMCAqG59QNRfNAJaMCNQYq+q_BV42_hA@mail.gmail.com>

Some observations:
1. With precision 100 I get correct result.
2. The issue is triggered by two calls of C=A*B, starting with A=0.3
works correctly.

Follow-Ups:
- Re: Numerical instability in extracting base B digits of the fractional part of real
  - From: Bill Allombert <Bill.Allombert@math.u-bordeaux.fr>

References:
- Numerical instability in extracting base B digits of the fractional part of real
  - From: Georgi Guninski <gguninski@gmail.com>
- Re: Numerical instability in extracting base B digits of the fractional part of real
  - From: Bill Allombert <Bill.Allombert@math.u-bordeaux.fr>
- Re: Numerical instability in extracting base B digits of the fractional part of real
  - From: Georgi Guninski <gguninski@gmail.com>
- Re: Numerical instability in extracting base B digits of the fractional part of real
  - From: Bill Allombert <Bill.Allombert@math.u-bordeaux.fr>
- Re: Numerical instability in extracting base B digits of the fractional part of real
  - From: Georgi Guninski <gguninski@gmail.com>