def METHOD_NAME(net, ppc):
    if not net._options["kappa"]:
        return
    topology = net._options["topology"]
    kappa_method = net._options["kappa_method"]
    if topology == "radial":
        kappa = _kappa(ppc["bus"][:, R_EQUIV] / ppc["bus"][:, X_EQUIV])
    elif kappa_method in ["C", "c"]:
        kappa = _kappa_method_c(net, ppc)
    elif kappa_method in ["B", "b"]:
        kappa = _kappa_method_b(net, ppc)
    else:
        raise ValueError("Unknown kappa method %s - specify B or C"%kappa_method)
    # ppc["bus"][:, KAPPA] = kappa
    # if kappa is already defined in a previous step (e.g. for sgen DFIG kappa is provided by the manufacturer)
    ppc["bus"][:, KAPPA] = np.where(np.isnan(ppc["bus"][:, KAPPA]), kappa, ppc["bus"][:, KAPPA])