Comment #2 on issue 2802 by [email protected]: solve error with expression with derivative
http://code.google.com/p/sympy/issues/detail?id=2802
I don't see the problem: you isolated (not solved) the equation for f(t). would you prefer that it solved the differential equation? But if so, then should `solve(exp(x) + sin(x), exp(x))` fail or should it give [-sin(x)]? This is all part of the special function and derivative handling introduced in response to http://code.google.com/p/sympy/issues/detail?id=626 . Perhaps the change there was too aggressive and should have just handled the Derivative instances and function *if there is no derivative involving that function*. This is sort of how the request to solve a function behaves: Traceback (most recent call last): File "<stdin>", line 1, in <module> File "sympy\solvers\solvers.py", line 521, in solve solution = _solve(f, *symbols, **flags) File "sympy\solvers\solvers.py", line 839, in _solve "\nNo algorithms are implemented to solve equation %s" % f) NotImplementedError: multiple generators [_F0, sin(_F0)] No algorithms are implemented to solve equation _F0 + sin(_F0) So I think the fix would be to dsolve if the item being requested is in the expr of a derivative. What do you think? -- You received this message because you are subscribed to the Google Groups "sympy-issues" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/sympy-issues?hl=en.
