def sympy_to_scipy(func, vars, params):
    """
    Convert a symbolic expression to one scipy digs. Not used by ``symfit`` any more.

    :param func: sympy expression
    :param vars: variables
    :param params: parameters
    :return: Scipy-style function to be used for numerical evaluation of the model.
    """
    lambda_func = sympy_to_py(func, vars, params)
    def f(x, p):
        """
        Scipy style function.

        :param x: list of arrays, NxM
        :param p: tuple of parameter values.
        """
        x = np.atleast_2d(x)
        y = [x[i] for i in range(len(x))] if len(x[0]) else []
        try:
            ans = lambda_func(*(y + list(p)))
        except TypeError:
            # Possibly this is a constant function in which case it only has Parameters.
            ans = lambda_func(*list(p))# * np.ones(x_shape)
        return ans

    return f
Convert a symbolic expression to one scipy digs. Not used by ``symfit`` any more.

    :param func: sympy expression
    :param vars: variables
    :param params: parameters
    :return: Scipy-style function to be used for numerical evaluation of the model.