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nerfstudio/pyrad/optimizers/optimizers.py
evonneng f67dca6f5b
refactor moving setup functions to associated classes; cleanup eval and benchmark scripts (#48)
* refactor code to move graph/dataset setup to respective files

* consolidated eval and benchmark script

* moved setup optimizers to its own thing
2022-06-13 19:05:07 -07:00

129 lines
4.6 KiB
Python

# Copyright 2022 The Plenoptix Team. 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.
"""
Optimizers class.
"""
from typing import Any, Dict, List
import numpy as np
from hydra.utils import instantiate
from omegaconf import DictConfig
from torch.nn import Parameter
from torch.optim.lr_scheduler import LambdaLR
from pyrad.utils import writer
def setup_optimizers(config: DictConfig, param_groups: Dict[str, List[Parameter]]) -> "Optimizers":
"""Helper to set up the optimizers
Args:
config (DictConfig): _description_
param_groups (Dict[str, List[Parameter]]): _description_
Returns:
Optimizers: _description_
"""
return Optimizers(config, param_groups)
class ExponentialDecaySchedule(LambdaLR):
"""Exponential learning rate decay function.
See https://github.com/google-research/google-research/blob/
fd2cea8cdd86b3ed2c640cbe5561707639e682f3/jaxnerf/nerf/utils.py#L360
for details.
"""
def __init__(self, optimizer, lr_init, lr_final, max_steps, lr_delay_steps=0, lr_delay_mult=1.0) -> None:
def func(step):
if lr_delay_steps > 0:
delay_rate = lr_delay_mult + (1 - lr_delay_mult) * np.sin(
0.5 * np.pi * np.clip(step / lr_delay_steps, 0, 1)
)
else:
delay_rate = 1.0
t = np.clip(step / max_steps, 0, 1)
log_lerp = np.exp(np.log(lr_init) * (1 - t) + np.log(lr_final) * t)
multiplier = (
log_lerp / lr_init
) # divided by lr_init because the multiplier is with the initial learning rate
return delay_rate * multiplier
super().__init__(optimizer, lr_lambda=func)
class Optimizers:
"""_summary_"""
def __init__(self, config: DictConfig, param_groups: Dict[str, List[Parameter]]):
"""_summary_
Args:
config (DictConfig): _description_
param_dict (Dict[str, List[Parameter]]): _description_
"""
self.config = config
self.optimizers = {}
self.schedulers = {}
for param_group_name, params in param_groups.items():
lr_init = config[param_group_name].optimizer.lr
self.optimizers[param_group_name] = instantiate(config[param_group_name].optimizer, params=params)
if config[param_group_name].scheduler:
self.schedulers[param_group_name] = instantiate(
config[param_group_name].scheduler, optimizer=self.optimizers[param_group_name], lr_init=lr_init
)
def optimizer_step(self, param_group_name: str) -> None:
"""fetch and step corresponding optimizer
Args:
param_group_name (str): name of optimizer to step forward
"""
self.optimizers[param_group_name].step()
def scheduler_step(self, param_group_name: str) -> None:
"""fetch and step corresponding scheduler
Args:
param_group_name (str): name of scheduler to step forward
"""
if self.config.param_group_name.scheduler:
self.schedulers[param_group_name].step()
def zero_grad_all(self):
"""zero the gradients for all optimizer parameters"""
for _, optimizer in self.optimizers.items():
optimizer.zero_grad()
def optimizer_step_all(self):
"""Run step for all optimizers."""
for _, optimizer in self.optimizers.items():
# note that they key is the parameter name
optimizer.step()
def scheduler_step_all(self, step):
"""Run step for all schedulers."""
for param_group_name, scheduler in self.schedulers.items():
scheduler.step()
# TODO(ethan): clean this up. why is there indexing into a list?
lr = scheduler.get_last_lr()[0]
writer.put_scalar(name=f"learning_rate/{param_group_name}", scalar=lr, step=step)
def load_optimizers(self, loaded_state: Dict[str, Any]) -> None:
"""Helper to load the optimizer state from previous checkpoint"""
for k, v in loaded_state["optimizers"].items():
self.optimizers[k].load_state_dict(v)