train_tnn : schedule -> tnn -> tnnex * tnnex -> tnn
Train a tree neural network (TNN) on a set of examples via backpropagation to minimize mean square error.
Hyperparameters such as batch size, learning rate and number of epochs can be set
in the schedule arguments. The initial TNN can be constructed by calling
mlTreeNeuralNetwork.random_tnn. Examples consists of a term t and a list l.
The term t is expected to be lambda-free with each operator appearing with a
unique arity. The list l is expected to be a list of real numbers between 0 and
1. In the case of a simple objective each example (t,l) is to be written as
[(h(t),l)] where h is a variable representing the head network. For multiple
objectives, one can write [(h1(t),l1),...,(hn(t),ln)] for a single example.
The created list of examples is to be split into a training set and a test set (possibly empty).
Fails when dimension constraints are not respected (see mlTreeNeuralNetwork.random_tnn) or a variable/constant from
the examples is not defined in the TNN.
See the end of the file src/AI/machine_learning/mlTreeNeuralNetwork.sml for
a toy example.