| # Copyright 2019 DeepMind Technologies Limited. All Rights Reserved. | |
| # | |
| # Licensed under the Apache License, Version 2.0 (the "License"); | |
| # you may not use this file except in compliance with the License. | |
| # You may obtain a copy of the License at | |
| # | |
| # http://www.apache.org/licenses/LICENSE-2.0 | |
| # | |
| # Unless required by applicable law or agreed to in writing, software | |
| # distributed under the License is distributed on an "AS IS" BASIS, | |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
| # See the License for the specific language governing permissions and | |
| # limitations under the License. | |
| # ============================================================================== | |
| """Utilities to join schedules.""" | |
| from typing import Sequence | |
| import chex | |
| import jax.numpy as jnp | |
| from optax._src import base | |
| def join_schedules( | |
| schedules: Sequence[base.Schedule], | |
| boundaries: Sequence[int] | |
| ) -> base.Schedule: | |
| """Sequentially apply multiple schedules. | |
| Args: | |
| schedules: A list of callables (expected to be optax schedules). Each | |
| schedule will receive a step count indicating the number of steps since | |
| the previous boundary transition. | |
| boundaries: A list of integers (of length one less than schedules) that | |
| indicate when to transition between schedules. | |
| Returns: | |
| schedule: A function that maps step counts to values. | |
| """ | |
| def schedule(step: chex.Numeric) -> chex.Numeric: | |
| output = schedules[0](step) | |
| for boundary, schedule in zip(boundaries, schedules[1:]): | |
| output = jnp.where(step < boundary, output, schedule(step - boundary)) | |
| return output | |
| return schedule | |