I am missing Seek operation over the MinibatchSource. Lets say I need to run the validation only over first 1000 samples in validation data after every epoch. With the current implementation, I need to initialize the MinibatchSource every time the validation kicks off during training to seek the MinibatchSource at the beginning of the file. One way could be to provide the reset operation over the MinibatchSource that sets the next minibatch at the beginning of the data.
From CNTK team:
This can be achieved using the “get_checkpoint_state” and “restore_from_checkpoint” methods on MinibatchSource. The former creates a dictionary object containing the necessary state denoting the MinibatchSource position at the time and “restore_from_checkpoint” effectively “seeks” the MinibatchSource back to that position.