r"""The netflux network for the reaction from
        A=[0,...,a] => B=[b,...,M].

        Parameters
        ----------
        a : int
            State index
        b : int
            State index

        Returns
        -------
        netflux : (M, M) ndarray
            Matrix of flux values between pairs of states.

def netflux(self, a, b):
        r"""The netflux network for the reaction from
        A=[0,...,a] => B=[b,...,M].

        Parameters
        ----------
        a : int
            State index
        b : int
            State index

        Returns
        -------
        netflux : (M, M) ndarray
            Matrix of flux values between pairs of states.

        """
        flux = self.flux(a, b)
        netflux = flux - np.transpose(flux)
        ind = (netflux < 0.0)
        netflux[ind] = 0.0
        return netflux