It seems to me that the assumption system is a better place to put all this. I may be wrong but I was left with the impression that it is meant to replace all the is_something stuff.
On 18 February 2012 07:37, Nathan Alison <[email protected]> wrote: > It would be nice if we could have variables take an interval as an input > argument, to replace or augment the current system of "is_something" flags. > > Say, > >>>> x = Symbol('x', domain=Interval(0, oo)) >>>> x.is_positive > True >>>> x.is_real > True >>>> x.is_bounded > False > > The variable x would carry around its interval, and we could use interval > arithmetic on functions of variables to find the interval of an expression: > >>>> x = Symbol('x', domain=Interval(-1, 1)) >>>> y = Symbol('y', domain=Interval(0, 2)) >>>> (x+y).domain > Interval(-1, 3) > > Currently (I think), there's no way to specify a range that a symbol can > take to this extent. Hopefully, notation like this would simplify things > like solving equations within a bounded domain, perhaps. > > If we want to be really ambitious, since an Interval is simply a type of > set, we can extend this notation to support arbitrary sets, though > specifying a symbol to be in the set of Reals would not add any extra > functionality... > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To view this discussion on the web visit > https://groups.google.com/d/msg/sympy/-/peRtdNF7OioJ. > 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.
