Your message dated Fri, 12 Jun 2009 06:17:06 +0000
with message-id <[email protected]>
and subject line Bug#530381: fixed in mpmath 0.12-1
has caused the Debian Bug report #530381,
regarding python-mpmath: strangely high accuracy in computing pi
to be marked as done.
This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
Bug report if necessary, and/or fix the problem forthwith.
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--
530381: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=530381
Debian Bug Tracking System
Contact [email protected] with problems
--- Begin Message ---
Package: python-mpmath
Version: 0.11-2
Severity: normal
The following Python code uses mpmath to implement Salamin's algorithm
for computing pi (using arithmetic and geometric means). The number
of digits of accuracy should roughly double with each iteration, and
it does so if mp.dps=1000 (the number of digits is printed at the end
of each swing through the loop).
However, if mp.dps=4000, then the number of digits doubles for a few
iterations, then goes to infinity:
3.0
8.1
18.7
40.3
83.6
inf
inf
inf
Somehow the estimate became exactly equal to pi. It seems strange to
me and I wonder if it's a bug in one of the math functions like sqrt
or whether it's a feature. Or perhaps mpmath computes pi using the
same algorithm?
from mpmath import *
mp.dps = 4000
# a sequence is successive arithmetic means;
# g sequence is successive geometric means
a, b = 1, sqrt(0.5)
n = 1
sum = 0
factor = 2
while n < mp.dps-10:
n = -log(a*a-b*b)/log(10)
a,b = (a+b)/2, sqrt(a*b)
factor *= 2
sum += factor * (a*a-b*b)
M = (a+b)/2
estimate = 4*M*M/(1-sum)
digits = -log(abs(estimate-pi))/log(10)
print "%7.1f" % digits
-- System Information:
Debian Release: squeeze/sid
APT prefers unstable
APT policy: (500, 'unstable'), (1, 'experimental')
Architecture: i386 (i686)
Kernel: Linux 2.6.29-2-686 (SMP w/2 CPU cores)
Locale: LANG=en_US.utf8, LC_CTYPE=en_US.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash
Versions of packages python-mpmath depends on:
ii python-support 1.0.3 automated rebuilding support for P
python-mpmath recommends no packages.
Versions of packages python-mpmath suggests:
ii python-gmpy 1.03.ds-1 Interfaces GMP to Python for fast,
ii python-matplotlib 0.98.3-5 Python based plotting system in a
ii python-mpmath-doc 0.11-2 library for arbitrary-precision fl
-- no debconf information
--- End Message ---
--- Begin Message ---
Source: mpmath
Source-Version: 0.12-1
We believe that the bug you reported is fixed in the latest version of
mpmath, which is due to be installed in the Debian FTP archive:
mpmath_0.12-1.diff.gz
to pool/main/m/mpmath/mpmath_0.12-1.diff.gz
mpmath_0.12-1.dsc
to pool/main/m/mpmath/mpmath_0.12-1.dsc
mpmath_0.12.orig.tar.gz
to pool/main/m/mpmath/mpmath_0.12.orig.tar.gz
python-mpmath-doc_0.12-1_all.deb
to pool/main/m/mpmath/python-mpmath-doc_0.12-1_all.deb
python-mpmath_0.12-1_all.deb
to pool/main/m/mpmath/python-mpmath_0.12-1_all.deb
A summary of the changes between this version and the previous one is
attached.
Thank you for reporting the bug, which will now be closed. If you
have further comments please address them to [email protected],
and the maintainer will reopen the bug report if appropriate.
Debian distribution maintenance software
pp.
Sandro Tosi <[email protected]> (supplier of updated mpmath package)
(This message was generated automatically at their request; if you
believe that there is a problem with it please contact the archive
administrators by mailing [email protected])
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
Format: 1.8
Date: Fri, 12 Jun 2009 08:04:37 +0200
Source: mpmath
Binary: python-mpmath python-mpmath-doc
Architecture: source all
Version: 0.12-1
Distribution: unstable
Urgency: low
Maintainer: Debian Python Modules Team
<[email protected]>
Changed-By: Sandro Tosi <[email protected]>
Description:
python-mpmath - library for arbitrary-precision floating-point arithmetic
python-mpmath-doc - library for arbitrary-precision floating-point arithmetic
- Docum
Closes: 530381
Changes:
mpmath (0.12-1) unstable; urgency=low
.
* New upstream release
- pi calculation precision fixed; Closes: #530381
* debian/{control, rules}
- added dpatch
* debian/patches/10_fix_test.dpatch
- added to fix test execution (solution provided by upstream author)
* debian/control
- bump Standards-Version to 3.8.1
+ added debian/README.source
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python-mpmath-doc_0.12-1_all.deb
Checksums-Sha256:
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Files:
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511fa67cb18b385e33c01cf6465ca267 280474 python optional mpmath_0.12.orig.tar.gz
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python-mpmath_0.12-1_all.deb
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python-mpmath-doc_0.12-1_all.deb
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