Source code for monai.handlers.utils

# Copyright (c) MONAI Consortium
# 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.

from __future__ import annotations

import os
from collections import OrderedDict
from collections.abc import Callable, Sequence
from typing import TYPE_CHECKING, Any

import numpy as np
import torch

from monai.config import IgniteInfo, KeysCollection, PathLike
from monai.utils import ensure_tuple, look_up_option, min_version, optional_import

idist, _ = optional_import("ignite", IgniteInfo.OPT_IMPORT_VERSION, min_version, "distributed")
if TYPE_CHECKING:
    from ignite.engine import Engine
else:
    Engine, _ = optional_import("ignite.engine", IgniteInfo.OPT_IMPORT_VERSION, min_version, "Engine")

__all__ = ["stopping_fn_from_metric", "stopping_fn_from_loss", "write_metrics_reports", "from_engine"]


[docs] def stopping_fn_from_metric(metric_name: str) -> Callable[[Engine], Any]: """ Returns a stopping function for ignite.handlers.EarlyStopping using the given metric name. """ def stopping_fn(engine: Engine) -> Any: return engine.state.metrics[metric_name] return stopping_fn
[docs] def stopping_fn_from_loss() -> Callable[[Engine], Any]: """ Returns a stopping function for ignite.handlers.EarlyStopping using the loss value. """ def stopping_fn(engine: Engine) -> Any: return -engine.state.output # type:ignore return stopping_fn
[docs] def write_metrics_reports( save_dir: PathLike, images: Sequence[str] | None, metrics: dict[str, torch.Tensor | np.ndarray] | None, metric_details: dict[str, torch.Tensor | np.ndarray] | None, summary_ops: str | Sequence[str] | None, deli: str = ",", output_type: str = "csv", ) -> None: """ Utility function to write the metrics into files, contains 3 parts: 1. if `metrics` dict is not None, write overall metrics into file, every line is a metric name and value pair. 2. if `metric_details` dict is not None, write raw metric data of every image into file, every line for 1 image. 3. if `summary_ops` is not None, compute summary based on operations on `metric_details` and write to file. Args: save_dir: directory to save all the metrics reports. images: name or path of every input image corresponding to the metric_details data. if None, will use index number as the filename of every input image. metrics: a dictionary of (metric name, metric value) pairs. metric_details: a dictionary of (metric name, metric raw values) pairs, usually, it comes from metrics computation, for example, the raw value can be the mean_dice of every channel of every input image. summary_ops: expected computation operations to generate the summary report. it can be: None, "*" or list of strings, default to None. None - don't generate summary report for every expected metric_details. "*" - generate summary report for every metric_details with all the supported operations. list of strings - generate summary report for every metric_details with specified operations, they should be within list: ["mean", "median", "max", "min", "<int>percentile", "std", "notnans"]. the number in "<int>percentile" should be [0, 100], like: "15percentile". default: "90percentile". for more details, please check: https://numpy.org/doc/stable/reference/generated/numpy.nanpercentile.html. note that: for the overall summary, it computes `nanmean` of all classes for each image first, then compute summary. example of the generated summary report:: class mean median max 5percentile 95percentile notnans class0 6.0000 6.0000 7.0000 5.1000 6.9000 2.0000 class1 6.0000 6.0000 6.0000 6.0000 6.0000 1.0000 mean 6.2500 6.2500 7.0000 5.5750 6.9250 2.0000 deli: the delimiter character in the saved file, default to "," as the default output type is `csv`. to be consistent with: https://docs.python.org/3/library/csv.html#csv.Dialect.delimiter. output_type: expected output file type, supported types: ["csv"], default to "csv". """ if output_type.lower() != "csv": raise ValueError(f"unsupported output type: {output_type}.") if not os.path.exists(save_dir): os.makedirs(save_dir) if metrics is not None and len(metrics) > 0: with open(os.path.join(save_dir, "metrics.csv"), "w") as f: for k, v in metrics.items(): f.write(f"{k}{deli}{str(v)}\n") if metric_details is not None and len(metric_details) > 0: for k, v in metric_details.items(): if isinstance(v, torch.Tensor): v = v.cpu().numpy() if v.ndim == 0: # reshape to [1, 1] if no batch and class dims v = v.reshape((1, 1)) elif v.ndim == 1: # reshape to [N, 1] if no class dim v = v.reshape((-1, 1)) # add the average value of all classes to v class_labels = ["class" + str(i) for i in range(v.shape[1])] + ["mean"] v = np.concatenate([v, np.nanmean(v, axis=1, keepdims=True)], axis=1) with open(os.path.join(save_dir, f"{k}_raw.csv"), "w") as f: f.write(f"filename{deli}{deli.join(class_labels)}\n") for i, b in enumerate(v): f.write( f"{images[i] if images is not None else str(i)}{deli}" f"{deli.join([f'{c:.4f}' if isinstance(c, (int, float)) else str(c) for c in b])}\n" ) if summary_ops is not None: supported_ops = OrderedDict( { "mean": np.nanmean, "median": np.nanmedian, "max": np.nanmax, "min": np.nanmin, "90percentile": lambda x: np.nanpercentile(x[0], x[1]), "std": np.nanstd, "notnans": lambda x: (~np.isnan(x)).sum(), } ) ops = ensure_tuple(summary_ops) if "*" in ops: ops = tuple(supported_ops.keys()) def _compute_op(op: str, d: np.ndarray) -> Any: if not op.endswith("percentile"): c_op = look_up_option(op, supported_ops) return c_op(d) threshold = int(op.split("percentile")[0]) return supported_ops["90percentile"]((d, threshold)) # type: ignore with open(os.path.join(save_dir, f"{k}_summary.csv"), "w") as f: f.write(f"class{deli}{deli.join(ops)}\n") for i, c in enumerate(np.transpose(v)): f.write(f"{class_labels[i]}{deli}{deli.join([f'{_compute_op(k, c):.4f}' for k in ops])}\n")
[docs] def from_engine(keys: KeysCollection, first: bool = False) -> Callable: """ Utility function to simplify the `batch_transform` or `output_transform` args of ignite components when handling dictionary or list of dictionaries(for example: `engine.state.batch` or `engine.state.output`). Users only need to set the expected keys, then it will return a callable function to extract data from dictionary and construct a tuple respectively. If data is a list of dictionaries after decollating, extract expected keys and construct lists respectively, for example, if data is `[{"A": 1, "B": 2}, {"A": 3, "B": 4}]`, from_engine(["A", "B"]): `([1, 3], [2, 4])`. It can help avoid a complicated `lambda` function and make the arg of metrics more straight-forward. For example, set the first key as the prediction and the second key as label to get the expected data from `engine.state.output` for a metric:: from monai.handlers import MeanDice, from_engine metric = MeanDice( include_background=False, output_transform=from_engine(["pred", "label"]) ) Args: keys: specified keys to extract data from dictionary or decollated list of dictionaries. first: whether only extract specified keys from the first item if input data is a list of dictionaries, it's used to extract the scalar data which doesn't have batch dim and was replicated into every dictionary when decollating, like `loss`, etc. """ _keys = ensure_tuple(keys) def _wrapper(data): if isinstance(data, dict): return tuple(data[k] for k in _keys) if isinstance(data, list) and isinstance(data[0], dict): # if data is a list of dictionaries, extract expected keys and construct lists, # if `first=True`, only extract keys from the first item of the list ret = [data[0][k] if first else [i[k] for i in data] for k in _keys] return tuple(ret) if len(ret) > 1 else ret[0] return _wrapper
def ignore_data(x: Any) -> None: """ Always return `None` for any input data. A typical usage is to avoid logging the engine output of every iteration during evaluation. """ return None