Beispiel #1
0
    def __new__(cls, variable, condition, base_set=S.UniversalSet):
        # nonlinsolve uses ConditionSet to return an unsolved system
        # of equations (see _return_conditionset in solveset) so until
        # that is changed we do minimal checking of the args
        if isinstance(variable, (Tuple, tuple)):  # unsolved eqns syntax
            variable = Tuple(*variable)
            condition = FiniteSet(*condition)
            return Basic.__new__(cls, variable, condition, base_set)
        condition = as_Boolean(condition)
        if isinstance(base_set, set):
            base_set = FiniteSet(*base_set)
        elif not base_set.is_set:
            raise TypeError('expecting set for base_set')
        if condition is S.false:
            return S.EmptySet
        if condition is S.true:
            return base_set
        if isinstance(base_set, EmptySet):
            return base_set
        know = None
        if isinstance(base_set, FiniteSet):
            sifted = sift(
                base_set, lambda _: fuzzy_bool(
                    condition.subs(variable, _)))
            if sifted[None]:
                know = FiniteSet(*sifted[True])
                base_set = FiniteSet(*sifted[None])
            else:
                return FiniteSet(*sifted[True])
        if isinstance(base_set, cls):
            s, c, base_set = base_set.args
            if variable == s:
                condition = And(condition, c)
            elif variable not in c.free_symbols:
                condition = And(condition, c.xreplace({s: variable}))
            elif s not in condition.free_symbols:
                condition = And(condition.xreplace({variable: s}), c)
                variable = s
            else:
                # user will have to use cls.variable to get symbol
                dum = Symbol('lambda')
                if dum in condition.free_symbols or \
                        dum in c.free_symbols:
                    dum = Dummy(str(dum))
                condition = And(
                    condition.xreplace({variable: dum}),
                    c.xreplace({s: dum}))
                variable = dum
        from sympy.tensor.indexed import Slice, IndexedBase
        assert isinstance(variable, (Symbol, Slice, IndexedBase))
#             s = Dummy('lambda')
#             if s not in condition.xreplace({variable: s}).free_symbols:
#                 raise ValueError('non-symbol dummy not recognized in condition')
        if condition.is_BooleanFalse:
            return S.EmptySet
        rv = Basic.__new__(cls, variable, condition, base_set)
        return rv if know is None else Union(know, rv)
Beispiel #2
0
 def __new__(cls, sym, condition, base_set=S.UniversalSet):
     # nonlinsolve uses ConditionSet to return an unsolved system
     # of equations (see _return_conditionset in solveset) so until
     # that is changed we do minimal checking of the args
     if isinstance(sym, (Tuple, tuple)):  # unsolved eqns syntax
         sym = Tuple(*sym)
         condition = FiniteSet(*condition)
         return Basic.__new__(cls, sym, condition, base_set)
     condition = as_Boolean(condition)
     if isinstance(base_set, set):
         base_set = FiniteSet(*base_set)
     elif not isinstance(base_set, Set):
         raise TypeError('expecting set for base_set')
     if condition is S.false:
         return S.EmptySet
     if condition is S.true:
         return base_set
     if isinstance(base_set, EmptySet):
         return base_set
     know = None
     if isinstance(base_set, FiniteSet):
         sifted = sift(
             base_set, lambda _: fuzzy_bool(
                 condition.subs(sym, _)))
         if sifted[None]:
             know = FiniteSet(*sifted[True])
             base_set = FiniteSet(*sifted[None])
         else:
             return FiniteSet(*sifted[True])
     if isinstance(base_set, cls):
         s, c, base_set = base_set.args
         if sym == s:
             condition = And(condition, c)
         elif sym not in c.free_symbols:
             condition = And(condition, c.xreplace({s: sym}))
         elif s not in condition.free_symbols:
             condition = And(condition.xreplace({sym: s}), c)
             sym = s
         else:
             # user will have to use cls.sym to get symbol
             dum = Symbol('lambda')
             if dum in condition.free_symbols or \
                     dum in c.free_symbols:
                 dum = Dummy(str(dum))
             condition = And(
                 condition.xreplace({sym: dum}),
                 c.xreplace({s: dum}))
             sym = dum
     if not isinstance(sym, Symbol):
         s = Dummy('lambda')
         if s not in condition.xreplace({sym: s}).free_symbols:
             raise ValueError(
                 'non-symbol dummy not recognized in condition')
     rv = Basic.__new__(cls, sym, condition, base_set)
     return rv if know is None else Union(know, rv)
Beispiel #3
0
 def __new__(cls, sym, condition, base_set=S.UniversalSet):
     # nonlinsolve uses ConditionSet to return an unsolved system
     # of equations (see _return_conditionset in solveset) so until
     # that is changed we do minimal checking of the args
     if isinstance(sym, (Tuple, tuple)):  # unsolved eqns syntax
         sym = Tuple(*sym)
         condition = FiniteSet(*condition)
         return Basic.__new__(cls, sym, condition, base_set)
     condition = as_Boolean(condition)
     if isinstance(base_set, set):
         base_set = FiniteSet(*base_set)
     elif not isinstance(base_set, Set):
         raise TypeError('expecting set for base_set')
     if condition is S.false:
         return S.EmptySet
     if condition is S.true:
         return base_set
     if isinstance(base_set, EmptySet):
         return base_set
     know = None
     if isinstance(base_set, FiniteSet):
         sifted = sift(
             base_set, lambda _: fuzzy_bool(
                 condition.subs(sym, _)))
         if sifted[None]:
             know = FiniteSet(*sifted[True])
             base_set = FiniteSet(*sifted[None])
         else:
             return FiniteSet(*sifted[True])
     if isinstance(base_set, cls):
         s, c, base_set = base_set.args
         if sym == s:
             condition = And(condition, c)
         elif sym not in c.free_symbols:
             condition = And(condition, c.xreplace({s: sym}))
         elif s not in condition.free_symbols:
             condition = And(condition.xreplace({sym: s}), c)
             sym = s
         else:
             # user will have to use cls.sym to get symbol
             dum = Symbol('lambda')
             if dum in condition.free_symbols or \
                     dum in c.free_symbols:
                 dum = Dummy(str(dum))
             condition = And(
                 condition.xreplace({sym: dum}),
                 c.xreplace({s: dum}))
             sym = dum
     if not isinstance(sym, Symbol):
         s = Dummy('lambda')
         if s not in condition.xreplace({sym: s}).free_symbols:
             raise ValueError(
                 'non-symbol dummy not recognized in condition')
     rv = Basic.__new__(cls, sym, condition, base_set)
     return rv if know is None else Union(know, rv)