def _logpdf(self, x, a, b, c):
        return np.log(a+b*(-special.expm1(-c*x))) + \
                (-a-b)*x+b*(-special.expm1(-c*x))/c
dataset/ETHPy150Open scipy/scipy/scipy/stats/_continuous_distns.py/genexpon_gen._logpdf/original