def lrfnepoch lr = 1e-35 + 1e-42 + 1e-51 return lrepochLR = tfkerascallbacksLearningRateSchedulerlrfn verbose = False

This is a function that defines a custom learning rate schedule for a Keras neural network model. The function takes the current epoch number as input and returns the learning rate for that epoch.

In this particular implementation, the learning rate starts at 0.001 for the first 5 epochs, then drops to 0.0001 for the next 2 epochs, and finally drops to 0.00001 for the last epoch.

The LR callback is then created using this function, and it will be used during training to adjust the learning rate of the model at the beginning of each epoch