如何绘制一个keras实验的学习曲线? [英] How to plot a learning curve for a keras experiment?
问题描述
我正在使用keras训练RNN,并想了解验证准确性如何随数据集大小而变化. Keras的历史记录对象中有一个名为val_acc
的列表,该列表会在每个纪元后以相应的验证集准确性(
I'm training an RNN using keras and would like to see how the validation accuracy changes with the data set size. Keras has a list called val_acc
in its history object which gets appended after every epoch with the respective validation set accuracy (link to the post in google group). I want to get the average of val_acc
for the number of epochs run and plot that against the respective data set size.
问题:如何获取val_acc
列表中的元素并执行类似numpy.mean(val_acc)
的操作?
Question: How can I retrieve the elements in the val_acc
list and perform an operation like numpy.mean(val_acc)
?
编辑:正如@runDOSrun所说,获取val_acc
的均值没有意义.让我集中精力获取最终的val_acc
.
As @runDOSrun said, getting the mean of the val_acc
s doesn't make sense. Let me focus on getting the final val_acc
.
我尝试了@nemo的建议,但是没有运气.这是我打印时得到的
I tried what's been suggested by @nemo but no luck. Here's what I got when I print
model.fit(X_train, y_train, batch_size = 512, nb_epoch = 5, validation_split = 0.05).__dict__
输出:
{'model': <keras.models.Sequential object at 0x000000001F752A90>, 'params': {'verbose': 1, 'nb_epoch': 5, 'batch_size': 512, 'metrics': ['loss', 'val_loss'], 'nb_sample': 1710, 'do_validation': True}, 'epoch': [0, 1, 2, 3, 4], 'history': {'loss': [0.96936064512408959, 0.66933631673890948, 0.63404161288724303, 0.62268789783555867, 0.60833334699708819], 'val_loss': [0.84040999412536621, 0.75676006078720093, 0.73714292049407959, 0.71032363176345825, 0.71341043710708618]}}
在我的历史词典中,没有列表显示为val_acc
.
It turns out there's no list as val_acc
in my history dictionary.
问题:如何在history
词典中包含val_acc
?
Question: How to include val_acc
in to the history
dictionary?
推荐答案
要获取精度值,您需要请求在fit
期间计算它们,因为精度不是目标函数,而是(通用)度量.有时计算准确性没有意义,因此在Keras中默认情况下未启用它.但是,它是一个内置指标,很容易添加.
To get accuracy values, you need to request that they are calculated during fit
, because accuracy is not an objective function, but a (common) metric. Sometimes calculating accuracy does not make sense, so it is not enabled by default in Keras. However, it is a built-in metric, and easy to add.
要添加指标,请在model.compile
中使用metrics=['accuracy']
参数.
To add the metric, use metrics=['accuracy']
parameter to model.compile
.
在您的示例中:
history = model.fit(X_train, y_train, batch_size = 512,
nb_epoch = 5, validation_split = 0.05)
然后您可以按history.history['val_acc']
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