def _complex_expand_series(context, builder, ty, initial, x, coefs):
    """this is used to implement approximations using series that are
    quite common in NumPy's source code to improve precision when the
    magnitude of the arguments is small. In funcs.inc.src this is
    implemented by repeated use of the macro "SERIES_HORNER_TERM
    """
    assert types.complex_domain in ty
    binary_sig = typing.signature(*[ty]*3)
    accum = context.make_complex(builder, ty, value=initial)
    ONE = context.get_constant(ty.underlying_float, 1.0)
    for coef in reversed(coefs):
        constant = context.get_constant(ty.underlying_float, coef)
        value = numbers.complex_mul_impl(context, builder, binary_sig,
                                          [x, accum._getvalue()])
        accum._setvalue(value)
        accum.real = builder.fadd(ONE, builder.fmul(accum.real, constant))
        accum.imag = builder.fmul(accum.imag, constant)

    return accum._getvalue()
dataset/ETHPy150Open numba/numba/numba/targets/npyfuncs.py/_complex_expand_series/swapped operands of `in`