Limit of rational expression with hypergeometric function #11465
Description
I've got an error when trying to calculate a limit of rational expression with hypergeometric function. It reproduces with this simple example (expression equivalents to exp(-x)):
import sympy
from sympy.abc import x
sympy.limit( 1 / sympy.hyper( (1,), (1,), x ), x, 0 ).doit()I use sympy 1.0 and python 3.5.
Traceback:
AttributeError Traceback (most recent call last)
<ipython-input-2-e68e19221d68> in <module>()
1 import sympy
2 from sympy.abc import x
----> 3 sympy.limit( 1 / sympy.hyper( (1,), (1,), x ), x, 0 ).doit()
/usr/local/lib/python3.5/site-packages/sympy/series/limits.py in limit(e, z, z0, dir)
43 """
44
---> 45 return Limit(e, z, z0, dir).doit(deep=False)
46
47
/usr/local/lib/python3.5/site-packages/sympy/series/limits.py in doit(self, **hints)
170
171 try:
--> 172 r = gruntz(e, z, z0, dir)
173 if r is S.NaN:
174 raise PoleError()
/usr/local/lib/python3.5/site-packages/sympy/series/gruntz.py in gruntz(e, z, z0, dir)
649 else:
650 raise NotImplementedError("dir must be '+' or '-'")
--> 651 r = limitinf(e0, z)
652
653 # This is a bit of a heuristic for nice results... we always rewrite
/usr/local/lib/python3.5/site-packages/sympy/core/cache.py in wrapper(*args, **kwargs)
91 def wrapper(*args, **kwargs):
92 try:
---> 93 retval = cfunc(*args, **kwargs)
94 except TypeError:
95 retval = func(*args, **kwargs)
/usr/local/lib/python3.5/site-packages/sympy/series/gruntz.py in limitinf(e, x)
422 e = e.subs(x, p)
423 x = p
--> 424 c0, e0 = mrv_leadterm(e, x)
425 sig = sign(e0, x)
426 if sig == 1:
/usr/local/lib/python3.5/site-packages/sympy/core/cache.py in wrapper(*args, **kwargs)
91 def wrapper(*args, **kwargs):
92 try:
---> 93 retval = cfunc(*args, **kwargs)
94 except TypeError:
95 retval = func(*args, **kwargs)
/usr/local/lib/python3.5/site-packages/sympy/series/gruntz.py in mrv_leadterm(e, x)
504 w = Dummy("w", real=True, positive=True, finite=True)
505 f, logw = rewrite(exps, Omega, x, w)
--> 506 series = calculate_series(f, w, logx=logw)
507 return series.leadterm(w)
508
/usr/local/lib/python3.5/site-packages/sympy/series/gruntz.py in calculate_series(e, x, logx)
460 from sympy.polys import cancel
461
--> 462 for t in e.lseries(x, logx=logx):
463 t = cancel(t)
464
/usr/local/lib/python3.5/site-packages/sympy/core/expr.py in yield_lseries(s)
2552 def yield_lseries(s):
2553 """Return terms of lseries one at a time."""
-> 2554 for si in s:
2555 if not si.is_Add:
2556 yield si
/usr/local/lib/python3.5/site-packages/sympy/core/expr.py in _eval_lseries(self, x, logx)
2617 # terms.
2618 n = 0
-> 2619 series = self._eval_nseries(x, n=n, logx=logx)
2620 if not series.is_Order:
2621 if series.is_Add:
/usr/local/lib/python3.5/site-packages/sympy/core/power.py in _eval_nseries(self, x, n, logx)
1147
1148 try:
-> 1149 ord = b.as_leading_term(x)
1150 cf = Order(ord, x).getn()
1151 if cf and cf.is_Number:
/usr/local/lib/python3.5/site-packages/sympy/core/cache.py in wrapper(*args, **kwargs)
91 def wrapper(*args, **kwargs):
92 try:
---> 93 retval = cfunc(*args, **kwargs)
94 except TypeError:
95 retval = func(*args, **kwargs)
/usr/local/lib/python3.5/site-packages/sympy/core/expr.py in as_leading_term(self, *symbols)
2779 if x not in self.free_symbols:
2780 return self
-> 2781 obj = self._eval_as_leading_term(x)
2782 if obj is not None:
2783 return powsimp(obj, deep=True, combine='exp')
/usr/local/lib/python3.5/site-packages/sympy/core/function.py in _eval_as_leading_term(self, x)
681 """
682 from sympy import Order
--> 683 args = [a.as_leading_term(x) for a in self.args]
684 o = Order(1, x)
685 if any(x in a.free_symbols and o.contains(a) for a in args):
/usr/local/lib/python3.5/site-packages/sympy/core/function.py in <listcomp>(.0)
681 """
682 from sympy import Order
--> 683 args = [a.as_leading_term(x) for a in self.args]
684 o = Order(1, x)
685 if any(x in a.free_symbols and o.contains(a) for a in args):
AttributeError: 'TupleArg' object has no attribute 'as_leading_term'