mindspore2022/docs/api/api_python/mindspore.train/mindspore.train.callback.LearningRateScheduler.txt

Class mindspore.train.callback.LearningRateScheduler(learning_rate_function)

    在训练期间更改学习率。

    参数：
        learning_rate_function (Function)：在训练期间更改学习率的函数。

    示例：
        >>> from mindspore import Model
        >>> from mindspore.train.callback import LearningRateScheduler
        >>> import mindspore.nn as nn
        ...
        >>> def learning_rate_function(lr, cur_step_num):
        ...     if cur_step_num%1000 == 0:
        ...         lr = lr*0.1
        ...     return lr
        ...
        >>> lr = 0.1
        >>> momentum = 0.9
        >>> net = Net()
        >>> loss = nn.SoftmaxCrossEntropyWithLogits()
        >>> optim = nn.Momentum(net.trainable_params(), learning_rate=lr, momentum=momentum)
        >>> model = Model(net, loss_fn=loss, optimizer=optim)
        ...
        >>> dataset = create_custom_dataset("custom_dataset_path")
        >>> model.train(1, dataset, callbacks=[LearningRateScheduler(learning_rate_function)],
        ...             dataset_sink_mode=False)
    

step_end(run_context)

        在step结束时更改学习率。

        参数：
            run_context (RunContext)：包含模型的一些基本信息。