Opened 3 years ago

Closed 2 years ago

# Hypergeometric 2F1 fails to convert to SymPy

Reported by: Owned by: rws major sage-duplicate/invalid/wontfix symbolics N/A

### Description

In `interfaces/sympy.py` only 2F2 conversion is tested.

```sage: hypergeometric((a,b,),(c,),d)._sympy_()
/home/ralf/sage/local/lib/python2.7/site-packages/sage/symbolic/expression.pyx in sage.symbolic.expression.Expression._sympy_ (build/cythonized/sage/symbolic/expression.cpp:12147)()
1447         """
1448         from sage.symbolic.expression_conversions import sympy_converter
-> 1449         return sympy_converter(self)
1450
1451     def _algebraic_(self, field):

/home/ralf/sage/local/lib/python2.7/site-packages/sage/symbolic/expression_conversions.pyc in __call__(self, ex)
224             return self.tuple(ex)
225         else:
--> 226             return self.composition(ex, operator)
227
228     def get_fake_div(self, ex):

/home/ralf/sage/local/lib/python2.7/site-packages/sage/symbolic/expression_conversions.pyc in composition(self, ex, operator)
792         f_sympy = getattr(sympy, f, None)
793         if f_sympy:
--> 794             return f_sympy(*sympy.sympify(g, evaluate=False))
795         else:
796             return sympy.Function(str(f))(*g, evaluate=False)

/home/ralf/sage/local/lib/python2.7/site-packages/sympy/functions/special/hyper.pyc in __new__(cls, ap, bq, z)
180     def __new__(cls, ap, bq, z):
181         # TODO should we check convergence conditions?
--> 182         return Function.__new__(cls, _prep_tuple(ap), _prep_tuple(bq), z)
183
184     @classmethod

/home/ralf/sage/local/lib/python2.7/site-packages/sympy/functions/special/hyper.pyc in _prep_tuple(v)
42     """
43     from sympy import unpolarify
---> 44     return TupleArg(*[unpolarify(x) for x in v])
45
46

TypeError: 'Symbol' object is not iterable
```

### comment:1 Changed 2 years ago by chapoton

see #27741 for the reason

### comment:2 Changed 2 years ago by chapoton

• Milestone changed from sage-8.2 to sage-duplicate/invalid/wontfix
• Status changed from new to needs_review

### comment:3 Changed 2 years ago by chapoton

• Status changed from needs_review to positive_review

### comment:4 Changed 2 years ago by embray

• Resolution set to duplicate
• Status changed from positive_review to closed
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