tfl.lattice_lib.finalize_constraints

Approximately projects lattice weights to strictly satisfy all constraints.

tfl.lattice_lib.finalize_constraints(
    weights, lattice_sizes, monotonicities, edgeworth_trusts=None,
    trapezoid_trusts=None, output_min=None, output_max=None
)

This projeciton guarantees that constraints are strictly met, but it is not an exact projection w.r.t. the L2 norm. The computationally cost is O((num_monotonic_dims + num_trust_constraints) * num_lattice_weights).

See helper functions _approximately_project_* for details of the individual projection algorithms for each set of constraints. They are designed to be applied sequentially: monotonicity, then edgeworth, trapezoid, and bounds if necessary. This is because the projection algorithms are guaranteed to not violate previous constraints, though they may lead to violations of later constraints.

Args:

weights: Lattice weights tensor of shape: (prod(lattice_sizes), units).
lattice_sizes: List or tuple of integers which represents lattice sizes. which correspond to weights.
monotonicities: List or tuple of same length as lattice_sizes of {0, 1} which represents monotonicity constraints per dimension. 1 stands for increasing (non-decreasing in fact), 0 for no monotonicity constraints.
edgeworth_trusts: None or iterable of three-element tuples. First element is the index of the main (monotonic) feature. Second element is the index of the conditional feature. Third element is the direction of trust set to 1 if higher values of the conditional feature should increase trust in the main feature and -1 otherwise.
trapezoid_trusts: None or iterable of three-element tuples. First element is the index of the main (monotonic) feature. Second element is the index of the conditional feature. Third element is the direction of trust set to 1 if higher values of the conditional feature should increase trust in the main feature and -1 otherwise.
output_min: None or minimum possible output.
output_max: None or maximum possible output.

Returns:

Projected weights tensor of same shape as weights.