Thank you Le mercredi 16 mars 2016 16:04:41 UTC+1, Kshitij Saraogi a écrit : > > Hello Sylvian, > > It seems `solve` is unable to handle this. > However, you can try using the `solve_poly_system` function in your case. > > `In []: result = solve_poly_system(system, unknowns)` > > This returns a NoneType result which is indicative of the system being > inconsistent. > I think we need to improve upon this in the codebase. > > Thanks for pointing it out. > > -------------------- > Kshitij Saraogi > > > On Wed, Mar 16, 2016 at 8:14 PM Sylvain Meunier <[email protected] > <javascript:>> wrote: > >> Hello, >> >> I'm trying to prove the following system has no solution using sympy (one >> of my first attempt to use sympy) : >> >> a_1 = Symbol('a_1') >> a_2 = Symbol('a_2') >> a_3 = Symbol('a_3') >> a_4 = Symbol('a_4') >> b_1 = Symbol('b_1') >> b_2 = Symbol('b_2') >> b_3 = Symbol('b_3') >> b_4 = Symbol('b_4') >> >> system = [ >> a_1*b_2 - a_2*b_1 - 1, >> a_1*b_3 - a_3*b_1, >> a_1*b_4 - a_4*b_1, >> a_2*b_3 - a_3*b_2, >> a_2*b_4 - a_4*b_2, >> a_3*b_4 - a_4*b_3 - 1 >> ] >> >> unknowns = [ >> a_1, a_2, a_3, a_4, b_1, b_2, b_3, b_4 >> ] >> >> result = solve(system, unknowns) >> >> I expect result would be an empty dictionary but an exception is raised : >> >> Traceback (most recent call last): >> File "D:\Sandbox\galgebra\tests\test_chapter2.py", line 162, in test >> R = solve(system, unknowns) >> File >> "D:\Tools\WinPython-2.7\python-2.7.10.amd64\lib\site-packages\sympy\solvers\solvers.py", >> >> line 911, in solve >> solution = _solve_system(f, symbols, **flags) >> File >> "D:\Tools\WinPython-2.7\python-2.7.10.amd64\lib\site-packages\sympy\solvers\solvers.py", >> >> line 1522, in _solve_system >> raise NotImplementedError('no valid subset found') >> NotImplementedError: no valid subset found >> >> Best regards >> >> Sylvain >> >> -- >> You received this message because you are subscribed to the Google Groups >> "sympy" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] <javascript:>. >> To post to this group, send email to [email protected] <javascript:> >> . >> Visit this group at https://groups.google.com/group/sympy. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/sympy/3af4090c-6e34-455a-afc0-7e11bf39c172%40googlegroups.com >> >> <https://groups.google.com/d/msgid/sympy/3af4090c-6e34-455a-afc0-7e11bf39c172%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> >
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