symbolic floor,ceil,factorial need _evalf_ too

[rwst]

With

sage: f(x) = floor(x)
sage: g(x) = ceil(x)
sage: h(x) = factorial(x)

any of the following

sage: f(pi)._numerical_approx()
sage: g(pi)._numerical_approx()
sage: h(5)._numerical_approx()

will result in

src/sage/symbolic/expression.pyx in sage.symbolic.expression.Expression._numerical_approx (build/cythonized/sage/symbolic/expression.cpp:27487)()
   4888         # in pynac
   4889         if is_a_numeric(x._gobj):
-> 4890             res = py_object_from_numeric(x._gobj)
   4891         elif  is_a_constant(x._gobj):
   4892             res = x.pyobject()

TypeError: cannot evaluate symbolic expression numerically

Component: symbolics

Author: Ralf Stephan

Branch/Commit: 0db18c4

Reviewer: Volker Braun

Issue created by migration from https://trac.sagemath.org/ticket/18091

[rwst]

Branch: u/rws/symbolic_floor_ceil_factorial_need__evalf__too

[rwst]

New commits:

0db18c4

18091: symbolic floor,ceil,factorial need `_evalf_` too

[rwst]

Author: Ralf Stephan

[rwst]

Commit: 0db18c4

[vbraun]

Reviewer: Volker Braun

[vbraun]

Changed branch from u/rws/symbolic_floor_ceil_factorial_need__evalf__too to 0db18c4