Using MLJ, after saving and retrieving a machine - Is there any method to retrieve the training data that was used to train this machine. I am unable to find any such method in documentation.
No, there is not currently a way to do this. Saving a machine does not save the data attached to it, only the model and learned parameters. Since datasets can be very large, this makes sense as default behaviour.
Feel free to open a feature request issue to add this as an option at MLJ.jl - or even better make a PR if you have the expertise 