Reputation: 115
I have created a custom schedule using tf.keras and I am encountering this error while saving the model:
NotImplementedError: Learning rate schedule must override get_config
The class looks like this:
class CustomSchedule(tf.keras.optimizers.schedules.LearningRateSchedule):
def __init__(self, d_model, warmup_steps=4000):
super(CustomSchedule, self).__init__()
self.d_model = d_model
self.d_model = tf.cast(self.d_model, tf.float32)
self.warmup_steps = warmup_steps
def __call__(self, step):
arg1 = tf.math.rsqrt(step)
arg2 = step * (self.warmup_steps**-1.5)
return tf.math.rsqrt(self.d_model) * tf.math.minimum(arg1, arg2)
def get_config(self):
config = {
'd_model':self.d_model,
'warmup_steps':self.warmup_steps
}
base_config = super(CustomSchedule, self).get_config()
return dict(list(base_config.items()) + list(config.items()))
Upvotes: 6
Views: 4211
Reputation: 106
When you are using the custom subclass model, it is a bit tricky to save the model architecture. Instead, it is easier to use the Model.save_weights() for saving the weights only.
If you change the code to this you will not see that error:
def get_config(self):
config = {
'd_model': self.d_model,
'warmup_steps': self.warmup_steps,
}
return config
Upvotes: 7