Opened 4 years ago
#21873 new defect
(Maxima's) solve is unable to solve a linear system with complicated coefficients
Reported by: | charpent | Owned by: | |
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Priority: | major | Milestone: | sage-7.5 |
Component: | symbolics | Keywords: | maxima solve |
Cc: | Merged in: | ||
Authors: | Reviewers: | ||
Report Upstream: | Reported upstream. No feedback yet. | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description
Long story : see this sage-support thread.
Short story : Let M_x be the matrix representing a rotation of angle theta about the x axis (in R^3
), and M_y the matrix representing a rotation of angle phi about the y axis. Trying to find by elementary methods the axis of the composition, i. e. solving M_y*M_x*V-V for V, the only solution found its the trivial null vector.
This has been reproduced in Maxima and reported on their bug system as bugs:3239, with no answer at the time of the present filing.
This can be worked around by using Sympy's solve, which involves some conversions using _sage_() (not that well documented).