I would like to know at what stage testing dataset is used CNNs? Is it used after completion of each batch or one epoch during training or is it used after completion of all the epochs ? I am a bit confused as to how these two processes run together ? Similarly gradient updation is done after each batch or each epoch ?
model.fit_generator(
aug.flow(x_train, y_train, batch_size=BATCH_SIZE),
validation_data=(x_test, y_test),
steps_per_epoch=len(x_train) // BATCH_SIZE,
epochs=EPOCHS, verbose=1, callbacks = callbacks)
From fit_generator it is only clear that images are loaded batch by batch onto memory.