lightning/pytorch_lightning/utilities/metrics.py

41 lines
1.4 KiB
Python

# Copyright The PyTorch Lightning team.
#
# 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.
"""Helper functions to operate on metric values. """
import torch
from pytorch_lightning.utilities.exceptions import MisconfigurationException
def metrics_to_scalars(metrics: dict) -> dict:
""" Recursively walk through a dictionary of metrics and convert single-item tensors to scalar values. """
# TODO: this is duplicated in MetricsHolder. should be unified
new_metrics = {}
for k, v in metrics.items():
if isinstance(v, torch.Tensor):
if v.numel() != 1:
raise MisconfigurationException(
f"The metric `{k}` does not contain a single element"
f" thus it cannot be converted to float. Found `{v}`"
)
v = v.item()
if isinstance(v, dict):
v = metrics_to_scalars(v)
new_metrics[k] = v
return new_metrics