def generate_thresholdcurve_data(evaluation, class_index):
    """
    Generates the threshold curve data from the evaluation object's predictions.

    :param evaluation: the evaluation to obtain the predictions from
    :type evaluation: Evaluation
    :param class_index: the 0-based index of the class-label to create the plot for
    :type class_index: int
    :return: the generated threshold curve data
    :rtype: Instances
    """
    jtc = JavaObject.new_instance("weka.classifiers.evaluation.ThresholdCurve")
    pred = javabridge.call(evaluation.jobject, "predictions", "()Ljava/util/ArrayList;")
    result = Instances(
        javabridge.call(jtc, "getCurve", "(Ljava/util/ArrayList;I)Lweka/core/Instances;", pred, class_index))
    return result
Generates the threshold curve data from the evaluation object's predictions.

    :param evaluation: the evaluation to obtain the predictions from
    :type evaluation: Evaluation
    :param class_index: the 0-based index of the class-label to create the plot for
    :type class_index: int
    :return: the generated threshold curve data
    :rtype: Instances