Opened 3 years ago
Closed 10 months ago
#26060 closed defect (fixed)
Wrong limit(x / (x + 2^x + cos(x)), x=-oo)
Reported by: | pelegm | Owned by: | |
---|---|---|---|
Priority: | major | Milestone: | sage-9.2 |
Component: | calculus | Keywords: | limit, maxima |
Cc: | slelievre | Merged in: | |
Authors: | Samuel Lelièvre | Reviewers: | Karl-Dieter Crisman |
Report Upstream: | Fixed upstream, in a later stable release. | Work issues: | |
Branch: | 7f96496 (Commits, GitHub, GitLab) | Commit: | 7f964965cc53474166342bcf9a1146233d9fc42b |
Dependencies: | #26625 | Stopgaps: |
Description (last modified by )
Up to Sage 8.7 this limit returns "und" for "undefined":
sage: limit(x / (x + 2^x + cos(x)), x=-infinity) und
while it should clearly be 1.
SymPy returns the correct result:
sage: limit(x / (x+2^x + cos(x)), x=-infinity, algorithm='sympy') 1
Reported to Maxima on 2018-08-15 as Maxima bug 3459, fixed there by Maxima commit 0c5c018 on 2018-08-30, fix included in Maxima 5.42.2 to which we upgrade in #26625, merged in Sage 8.8.beta7.
In Sage >= 8.8 we get the correct value for this limit:
sage: limit(x / (x + 2^x + cos(x)), x=-infinity) 1
This ticket adds a doctest for that limit computation.
Change History (19)
comment:1 Changed 3 years ago by
- Report Upstream changed from N/A to Reported upstream. No feedback yet.
comment:2 Changed 3 years ago by
- Report Upstream changed from Reported upstream. No feedback yet. to Reported upstream. Developers acknowledge bug.
comment:3 Changed 3 years ago by
- Report Upstream changed from Reported upstream. Developers acknowledge bug. to Fixed upstream, but not in a stable release.
comment:4 Changed 3 years ago by
(That was pretty fast work!)
comment:5 Changed 2 years ago by
- Cc slelievre added
- Dependencies set to #26625
- Description modified (diff)
- Keywords changed from limit,maxima to limit, maxima
- Milestone changed from sage-8.4 to sage-8.7
- Report Upstream changed from Fixed upstream, but not in a stable release. to Fixed upstream, in a later stable release.
After the upgrade to Maxima 5.42.2 in #26625, we should add a doctest here.
comment:6 Changed 2 years ago by
- Milestone changed from sage-8.7 to sage-8.8
Ticket retargeted after milestone closed (if you don't believe this ticket is appropriate for the Sage 8.8 release please retarget manually)
comment:7 Changed 2 years ago by
- Milestone sage-8.8 deleted
As the Sage-8.8 release milestone is pending, we should delete the sage-8.8 milestone for tickets that are not actively being worked on or that still require significant work to move forward. If you feel that this ticket should be included in the next Sage release at the soonest please set its milestone to the next release milestone (sage-8.9).
comment:8 Changed 11 months ago by
- Milestone set to sage-duplicate/invalid/wontfix
- Status changed from new to needs_review
Works in 9.2.beta10
comment:10 Changed 11 months ago by
- Branch set to public/ticket/26060
- Commit set to 7f964965cc53474166342bcf9a1146233d9fc42b
- Description modified (diff)
- Status changed from needs_work to needs_review
comment:11 Changed 11 months ago by
- Milestone changed from sage-duplicate/invalid/wontfix to sage-9.2
comment:12 Changed 11 months ago by
- Description modified (diff)
comment:13 Changed 11 months ago by
- Summary changed from Wrong limit calculation to Wrong limit(x / (x + 2^x + cos(x)), x=-oo)
comment:14 Changed 11 months ago by
Looks fine to me (assuming patchbot says it's fine), though all the other changes in typesetting could have occurred on another ticket. Thanks for doctesting!
comment:15 Changed 11 months ago by
- Status changed from needs_review to positive_review
comment:16 Changed 11 months ago by
- Reviewers set to Karl-Dieter Crisman
comment:17 Changed 11 months ago by
comment:18 Changed 11 months ago by
Sorry! Haven't been keeping "Trac" as much lately.
comment:19 Changed 10 months ago by
- Branch changed from public/ticket/26060 to 7f964965cc53474166342bcf9a1146233d9fc42b
- Resolution set to fixed
- Status changed from positive_review to closed
Apparently yes.
I've reported this at Maxima bug 3459.