# Revision history [back]

### "partial_fraction_decomposition" with "complex roots"

Hi six months ago I used a hint from Zimmerman's book

var('s')

L=2(s + 3)/(3s^2 + 13*s + 10)

C=ComplexField(53)

dec=Frac(C['s'])(L).partial_fraction_decomposition()

but this does not work anymore (see below). How to do this? Thanks

----> 2 dec=Frac(C['s'])(Lrs).partial_fraction_decomposition();

TypeError: ('cannot convert {!r}/{!r} to an element of {}', 2(s + 3)/(3s^2 + 13*s + 10), 1.00000000000000, Fraction Field of Univariate Polynomial Ring in s over Complex Field with 53 bits of precision)

/opt/sagemath-8.1/src/sage/structure/parent.pyx in sage.structure.parent.Parent.__call__ (build/cythonized/sage/structure/parent.c:9641)() 937 if mor is not None: 938 if no_extra_args: --> 939 return mor._call_(x) 940 else: 941 return mor._call_with_args(x, args, kwds)

/opt/sagemath-8.1/src/sage/structure/coerce_maps.pyx in sage.structure.coerce_maps.DefaultConvertMap_unique._call_ (build/cythonized/sage/structure/coerce_maps.c:4928)() 152 print(type(C), C) 153 print(type(C._element_constructor), C._element_constructor) --> 154 raise 155 156 cpdef Element _call_with_args(self, x, args=(), kwds={}):

/opt/sagemath-8.1/src/sage/structure/coerce_maps.pyx in sage.structure.coerce_maps.DefaultConvertMap_unique._call_ (build/cythonized/sage/structure/coerce_maps.c:4796)() 147 cdef Parent C = self._codomain 148 try: --> 149 return C._element_constructor(x) 150 except Exception: 151 if print_warnings:

/opt/sagemath-8.1/local/lib/python2.7/site-packages/sage/rings/fraction_field.py in _element_constructor_(self, x, y, coerce) 616 except AttributeError: 617 raise TypeError("cannot convert {!r}/{!r} to an element of {}", --> 618 x0, y0, self) 619 try: 620 return self._element_class(self, x, y, coerce=coerce)