forked from huawei/mindspore2022
38 lines
1.2 KiB
ReStructuredText
38 lines
1.2 KiB
ReStructuredText
.. py:class:: mindspore.train.callback.LearningRateScheduler(learning_rate_function)
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在训练期间更改学习率。
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**参数：**
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**learning_rate_function** (Function) - 在训练期间更改学习率的函数。
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**样例：**
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>>> from mindspore import Model
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>>> from mindspore.train.callback import LearningRateScheduler
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>>> import mindspore.nn as nn
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...
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>>> def learning_rate_function(lr, cur_step_num):
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... if cur_step_num%1000 == 0:
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... lr = lr*0.1
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... return lr
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...
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>>> lr = 0.1
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>>> momentum = 0.9
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>>> net = Net()
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>>> loss = nn.SoftmaxCrossEntropyWithLogits()
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>>> optim = nn.Momentum(net.trainable_params(), learning_rate=lr, momentum=momentum)
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>>> model = Model(net, loss_fn=loss, optimizer=optim)
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...
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>>> dataset = create_custom_dataset("custom_dataset_path")
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>>> model.train(1, dataset, callbacks=[LearningRateScheduler(learning_rate_function)],
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... dataset_sink_mode=False)
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.. py:method:: step_end(run_context)
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在step结束时更改学习率。
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**参数：**
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**run_context** (RunContext) - 包含模型的一些基本信息。
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