Plotting learning curve in keras gives KeyError: 'val_acc'

Question

I was trying to plot train and test learning curve in keras, however, the following code produces KeyError: \'val_acc error.

The official document

Answer 1

The main point everyone misses to mention is that this Key Error is related to the naming of metrics during model.compile(...). You need to be consistent with the way you name your accuracy metric inside model.compile(....,metrics=['']). Your history callback object will receive the dictionary containing key-value pairs as defined in metrics.

So, if your metric is metrics=['acc'], you can access them in history object with history.history['acc'] but if you define metric as metrics=['accuracy'], you need to change to history.history['accuracy'] to access the value, in order to avoid Key Error. I hope it helps.

N.B. Here's a link to the metrics you can use in Keras.