On Thu, Jun 16, 2011 at 10:47 AM, Ronan Lamy <[email protected]> wrote: > Le jeudi 16 juin 2011 à 17:09 +0100, Tom Bachmann a écrit : >> Let me jump ship here: is there an existing solution in sympy to >> simplify various conditions, involving inequalities etc? An easy example >> would be >> >> re(-a) + 2 < 2 ∧ 0 < re(a) >> >> which is just equivalent to re(a) > 0, but much more complicated things >> can happen. > > No, I don't think this exists. It would be very useful though. Some of > the infrastructure for this exists already (refine(), simplify(), ...) > and I think that your example could be made to work relatively easily, > but a full solution for this might be quite hard.
Also, how do you define "simpler"? Which is the most simple, x**2 > 1 or |x| > 1 or x > 1 | x < 1 (assume x is real)? Or is your main interest simply to remove redundant terms from an And? Aaron Meurer > >> On 16.06.2011 16:32, Matthew Rocklin wrote: >> > Hi everyone, I have a question about turning inequalities on symbols >> > into Intervals. >> > >> > I am currently able to do (and get much use out of) this >> > >>> reduce_poly_inequalities([[x>=0]], x, relational=False) >> > which returns the correct interval: >> > [0, ∞) >> > >> > I would like to be able to do this: >> > >>> reduce_poly_inequalities([[x>=y]], x, relational=False) >> > and get this >> > [y, ∞) >> > but instead I get this >> > NotImplementedError: inequality solving is not supported over ZZ[y] >> > >> > which is an error I think to preempt an error being caused in the >> > sympy.polys.rootoftools.RootOf class although at this point I'm in over >> > my head. >> > >> > Should I: >> > 1) investigate this more and see if I can fix things? >> > 2) make an issue? >> > 3) look for another way to solve my problem because this will be >> > difficult to fix? >> > >> > Best, >> > -Matt >> > >> > -- >> > You received this message because you are subscribed to the Google >> > Groups "sympy" 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?hl=en. >> > > > -- > You received this message because you are subscribed to the Google Groups > "sympy" 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?hl=en. > > -- You received this message because you are subscribed to the Google Groups "sympy" 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?hl=en.
