Opened 4 years ago

Closed 7 months ago

#25688 closed defect (fixed)

Inaccuracy in symbolic series result on 32bit Linux

Reported by: Ralf Stephan Owned by:
Priority: minor Milestone: sage-9.6
Component: symbolics Keywords: pynac, 32-bit, overflow
Cc: Samuel Lelièvre, Thierry Monteil Merged in:
Authors: Dave Morris Reviewers: Matthias Koeppe
Report Upstream: N/A Work issues:
Branch: 689e08f (Commits, GitHub, GitLab) Commit: 689e08f9393ac651c420546b0e63efbb1220156b
Dependencies: Stopgaps:

Status badges

Description

From https://trac.sagemath.org/ticket/24838#comment:64

On 32-bit:

File "src/sage/functions/hypergeometric.py", line 148, in sage.functions.hypergeometric
Failed example:
    hypergeometric_U(2, 2, x).series(x == 3, 100).subs(x=1).n()
Expected:
    0.403652637676806
Got:
    0.403651580752398

Pynac is not involved in the numerics (hypergeometric_U is not a GinacFunction), so the hypothesis is that the expression before .n() is different with 32bit Linux pynac-0.7.22.

Change History (13)

comment:1 Changed 16 months ago by Dave Morris

Branch: public/25688

comment:2 Changed 16 months ago by Dave Morris

Authors: Dave Morris
Commit: e8ee3fc291a8d547459e89ad40f3cf0e7a953d93
Dependencies: #31585
Keywords: pynac 32-bit overflow added
Milestone: sage-8.3sage-9.4
Status: newneeds_review

This bug is fixed by the pynac patch in #31585. (So the inaccuracy in the sum is due to an arithmetic overflow.)

There is only new commit in the branch here. It just deletes the "known bug" tag from the doctest in src/sage/functions/hypergeometric.py that is in the description of this ticket.


New commits:

f1a99fatrac 31585 pynac overflow patch
3fcf072add doctests
fdde3d9update pynac patch level
e8ee3fctrac 25688 remove "known bug" tag

comment:3 Changed 15 months ago by Dave Morris

Branch: public/25688public/25688r1

comment:4 Changed 15 months ago by Dave Morris

Commit: e8ee3fc291a8d547459e89ad40f3cf0e7a953d9373e975c28997f6662454b3b53dfe2cdebd22f410

Rebased on the new #31585 that eliminates a merge conflict.


New commits:

ecb99c8trac 31585 pynac overflow patch
2d04fa4add doctests
5a340ceupdate pynac patch level
73e975ctrac 25688 remove "known bug" tag

comment:5 Changed 14 months ago by Samuel Lelièvre

Cc: Samuel Lelièvre added
Status: needs_reviewneeds_work

Please rebase.

comment:6 Changed 14 months ago by Dave Morris

Branch: public/25688r1public/25688r2

comment:7 Changed 14 months ago by Dave Morris

Commit: 73e975c28997f6662454b3b53dfe2cdebd22f410689e08f9393ac651c420546b0e63efbb1220156b
Dependencies: #31585
Status: needs_workneeds_review

Thanks for pointing out the merge conflict -- I hadn't noticed. I rebased on 9.4b6 (and deleted the dependency on #31585, which has already been merged).


New commits:

689e08ftrac 25688 remove "known bug" tag

comment:8 Changed 13 months ago by Matthias Köppe

Milestone: sage-9.4sage-9.5

comment:9 Changed 11 months ago by Matthias Köppe

Cc: Thierry Monteil added

comment:10 Changed 10 months ago by Matthias Köppe

Milestone: sage-9.5sage-9.6

Stalled in needs_review or needs_info; likely won't make it into Sage 9.5.

comment:11 Changed 7 months ago by Matthias Köppe

Reviewers: Matthias Koeppe
Status: needs_reviewpositive_review

comment:12 Changed 7 months ago by Dave Morris

Thanks!

comment:13 Changed 7 months ago by Volker Braun

Branch: public/25688r2689e08f9393ac651c420546b0e63efbb1220156b
Resolution: fixed
Status: positive_reviewclosed
Note: See TracTickets for help on using tickets.