Opened 11 years ago
Last modified 6 years ago
#10311 new defect
solve()-ing Equations in CC
Reported by: | tux21b | Owned by: | burcin |
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Priority: | major | Milestone: | |
Component: | symbolics | Keywords: | |
Cc: | tux21b | Merged in: | |
Authors: | Reviewers: | ||
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description
The following looks like a bug to me, but feel free to correct me if I'm mistaken.
sage: var('z') sage: g1 = z^5 - (2 - I)*z^4 - (34 + 13*I)*z^3 + (22 - 51*I)*z^2 \ + (53 - I)*z - 728 - 196*I == 0 sage: sage: solve([g1], z) [0 == z^5 + (I - 2)*z^4 - (13*I + 34)*z^3 - (51*I - 22)*z^2 - (I - 53)*z - 196*I - 728] sage: sage: solve([g1, I == I], z) [[z == (-4.00420663449 - 1.03443096055*I)], [z == (7.03872088238 + 1.11154206861*I)], [z == (1.40276621 - 2.70758376454*I)], [z == ( -3.78854832152 - 0.122376366114*I)], [z == (1.35126786363 + 1.7528490226*I)]] sage: sage: solve([g1, z == z], z) [[z == (-4.00420663449 - 1.03443096055*I)], [z == (7.03872088238 + 1.11154206861*I)], [z == (1.40276621 - 2.70758376454*I)], [z == ( -3.78854832152 - 0.122376366114*I)], [z == (1.35126786363 + 1.7528490226*I)]]
I think the problem is that solve()
refuses to solve equation systems with more variables than equations, even if some of the variables are already known.
Regards
Christoph
Change History (3)
comment:1 Changed 10 years ago by
- Component changed from linear algebra to symbolics
- Owner changed from jason, was to burcin
comment:2 Changed 10 years ago by
This could be related to #10750.
comment:3 Changed 6 years ago by
Should be addressed by #18900.
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Yes, that looks suspicious to me. I tried replacing all the instances of I in g1 by
imag=CC((0,1))
, with no better luck.This is not really a linear algebra problem, but more of something to do with symbolics (where g1 lives) so I am going to change the component on this so it might get noticed sooner. If you haven't already, you might bring this up on sage-devel or sage-support - somebody might be able to confirm this as undesirable behavior, or offer a workaround.