Opened 6 years ago
Last modified 3 years ago
#18697 new defect
any FP number in an Expression without symbol should trigger evaluation
Reported by: | rws | Owned by: | |
---|---|---|---|
Priority: | major | Milestone: | sage-6.8 |
Component: | symbolics | Keywords: | |
Cc: | Merged in: | ||
Authors: | Reviewers: | ||
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | #10035 | Stopgaps: |
Description (last modified by )
sage: 0.1 * cos(pi/13) 0.100000000000000*cos(1/13*pi)
This is annoying because the 0.1
at once limits the precision of any other non-symbolic expression.
Change History (7)
comment:1 Changed 6 years ago by
- Report Upstream changed from N/A to Reported upstream. Developers acknowledge bug.
comment:2 Changed 6 years ago by
- Dependencies set to #10035
comment:3 Changed 6 years ago by
- Description modified (diff)
comment:4 Changed 6 years ago by
- Report Upstream changed from Reported upstream. Developers acknowledge bug. to Fixed upstream, but not in a stable release.
comment:5 Changed 6 years ago by
- Description modified (diff)
- Report Upstream changed from Fixed upstream, but not in a stable release. to N/A
Partial "fix" of Sage code removed, it was actually an unrelated Pynac issue, which is fixed in 0.4.2.
comment:6 follow-up: ↓ 7 Changed 4 years ago by
The problem with this ticket is shown by
sage: pi + RBF(1)
The expected output would be [4.141592653589793 +/- 5.61e-16]
, i.e. the same as with RBF(pi) + RBF(1)
. Constant conversions thus need to take the right parent into account. There may be multiple incompatible parents and that fact may be hidden deep in the expression tree.
comment:7 in reply to: ↑ 6 Changed 3 years ago by
Replying to rws:
There may be multiple incompatible parents and that fact may be hidden deep in the expression tree.
This is not a problem because we are evaluating depth-first. The only problem at all seems de-facto limited precision constants, in spite of #18255. Also this might be in the way: https://github.com/pynac/pynac/issues/311
People will complain if they cannot change this behaviour, so we need a hold context.