ined from the Jacobian
    approximation. If the step size is smaller than this, optimization
    is terminated as successful. If omitted, not used.
tol_norm : function(vector) -> scalar, optional
    Norm to use in convergence check. Default is the maximum norm.
line_search : {None, 'armijo' (default), 'wolfe'}, optional
    Which type of a line search to use to determine the step size in
    the direction given by the Jacobian approximation. Defaults to
    'armijo'.
jac_options : dict, optional
    Options for the respective Jacobian approximation.

    alpha : float, optional
        initial guess for the jacobian is (-1/alpha).
NrG