def _rational_(self):
"""
EXAMPLES::
sage: a = CFF(-17/389); a
[-1, 1, 21, 1, 7, 2]
sage: a._rational_()
-17/389
sage: QQ(a)
-17/389
"""
try:
return self.__rational
except AttributeError:
r = convergents(self._x)[-1]
self.__rational =r
return r
def _rational_(self):
"""
EXAMPLES::
sage: a = CFF(-17/389); a
[-1, 1, 21, 1, 7, 2]
sage: a._rational_()
-17/389
sage: QQ(a)
-17/389
"""
try:
return self.__rational
except AttributeError:
r = convergents(self._x)[-1]
self.__rational = r
return r
def convergents(self):
"""
Return a list of rational numbers, which are the partial
convergents of this continued fraction.
OUTPUT:
- list of rational numbers
EXAMPLES::
sage: a = CFF(pi, bits=34); a
[3, 7, 15, 1, 292]
sage: a.convergents()
[3, 22/7, 333/106, 355/113, 103993/33102]
sage: a.value()
103993/33102
sage: a[:-1].value()
355/113
"""
return convergents(self._x)
def convergents(self):
"""
Return a list of rational numbers, which are the partial
convergents of this continued fraction.
OUTPUT:
- list of rational numbers
EXAMPLES::
sage: a = CFF(pi, bits=34); a
[3, 7, 15, 1, 292]
sage: a.convergents()
[3, 22/7, 333/106, 355/113, 103993/33102]
sage: a.value()
103993/33102
sage: a[:-1].value()
355/113
"""
return convergents(self._x)
