Spaces:
Running
Running
# Copyright 2020 The HuggingFace Datasets Authors and the current dataset script contributor. | |
# | |
# 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. | |
"""Precision metric.""" | |
import datasets | |
from sklearn.metrics import precision_score | |
import evaluate | |
_DESCRIPTION = """ | |
Precision is the fraction of correctly labeled positive examples out of all of the examples that were labeled as positive. It is computed via the equation: | |
Precision = TP / (TP + FP) | |
where TP is the True positives (i.e. the examples correctly labeled as positive) and FP is the False positive examples (i.e. the examples incorrectly labeled as positive). | |
""" | |
_KWARGS_DESCRIPTION = """ | |
Args: | |
predictions (`list` of `int`): Predicted class labels. | |
references (`list` of `int`): Actual class labels. | |
labels (`list` of `int`): The set of labels to include when `average` is not set to `'binary'`. If `average` is `None`, it should be the label order. Labels present in the data can be excluded, for example to calculate a multiclass average ignoring a majority negative class. Labels not present in the data will result in 0 components in a macro average. For multilabel targets, labels are column indices. By default, all labels in `predictions` and `references` are used in sorted order. Defaults to None. | |
pos_label (`int`): The class to be considered the positive class, in the case where `average` is set to `binary`. Defaults to 1. | |
average (`string`): This parameter is required for multiclass/multilabel targets. If set to `None`, the scores for each class are returned. Otherwise, this determines the type of averaging performed on the data. Defaults to `'binary'`. | |
- 'binary': Only report results for the class specified by `pos_label`. This is applicable only if the classes found in `predictions` and `references` are binary. | |
- 'micro': Calculate metrics globally by counting the total true positives, false negatives and false positives. | |
- 'macro': Calculate metrics for each label, and find their unweighted mean. This does not take label imbalance into account. | |
- 'weighted': Calculate metrics for each label, and find their average weighted by support (the number of true instances for each label). This alters `'macro'` to account for label imbalance. This option can result in an F-score that is not between precision and recall. | |
- 'samples': Calculate metrics for each instance, and find their average (only meaningful for multilabel classification). | |
sample_weight (`list` of `float`): Sample weights Defaults to None. | |
zero_division (`int` or `string`): Sets the value to return when there is a zero division. Defaults to 'warn'. | |
- 0: Returns 0 when there is a zero division. | |
- 1: Returns 1 when there is a zero division. | |
- 'warn': Raises warnings and then returns 0 when there is a zero division. | |
Returns: | |
precision (`float` or `array` of `float`): Precision score or list of precision scores, depending on the value passed to `average`. Minimum possible value is 0. Maximum possible value is 1. Higher values indicate that fewer negative examples were incorrectly labeled as positive, which means that, generally, higher scores are better. | |
Examples: | |
Example 1-A simple binary example | |
>>> precision_metric = evaluate.load("precision") | |
>>> results = precision_metric.compute(references=[0, 1, 0, 1, 0], predictions=[0, 0, 1, 1, 0]) | |
>>> print(results) | |
{'precision': 0.5} | |
Example 2-The same simple binary example as in Example 1, but with `pos_label` set to `0`. | |
>>> precision_metric = evaluate.load("precision") | |
>>> results = precision_metric.compute(references=[0, 1, 0, 1, 0], predictions=[0, 0, 1, 1, 0], pos_label=0) | |
>>> print(round(results['precision'], 2)) | |
0.67 | |
Example 3-The same simple binary example as in Example 1, but with `sample_weight` included. | |
>>> precision_metric = evaluate.load("precision") | |
>>> results = precision_metric.compute(references=[0, 1, 0, 1, 0], predictions=[0, 0, 1, 1, 0], sample_weight=[0.9, 0.5, 3.9, 1.2, 0.3]) | |
>>> print(results) | |
{'precision': 0.23529411764705882} | |
Example 4-A multiclass example, with different values for the `average` input. | |
>>> predictions = [0, 2, 1, 0, 0, 1] | |
>>> references = [0, 1, 2, 0, 1, 2] | |
>>> results = precision_metric.compute(predictions=predictions, references=references, average='macro') | |
>>> print(results) | |
{'precision': 0.2222222222222222} | |
>>> results = precision_metric.compute(predictions=predictions, references=references, average='micro') | |
>>> print(results) | |
{'precision': 0.3333333333333333} | |
>>> results = precision_metric.compute(predictions=predictions, references=references, average='weighted') | |
>>> print(results) | |
{'precision': 0.2222222222222222} | |
>>> results = precision_metric.compute(predictions=predictions, references=references, average=None) | |
>>> print([round(res, 2) for res in results['precision']]) | |
[0.67, 0.0, 0.0] | |
""" | |
_CITATION = """ | |
@article{scikit-learn, | |
title={Scikit-learn: Machine Learning in {P}ython}, | |
author={Pedregosa, F. and Varoquaux, G. and Gramfort, A. and Michel, V. | |
and Thirion, B. and Grisel, O. and Blondel, M. and Prettenhofer, P. | |
and Weiss, R. and Dubourg, V. and Vanderplas, J. and Passos, A. and | |
Cournapeau, D. and Brucher, M. and Perrot, M. and Duchesnay, E.}, | |
journal={Journal of Machine Learning Research}, | |
volume={12}, | |
pages={2825--2830}, | |
year={2011} | |
} | |
""" | |
class Precision(evaluate.Metric): | |
def _info(self): | |
return evaluate.MetricInfo( | |
description=_DESCRIPTION, | |
citation=_CITATION, | |
inputs_description=_KWARGS_DESCRIPTION, | |
features=datasets.Features( | |
{ | |
"predictions": datasets.Sequence(datasets.Value("int32")), | |
"references": datasets.Sequence(datasets.Value("int32")), | |
} | |
if self.config_name == "multilabel" | |
else { | |
"predictions": datasets.Value("int32"), | |
"references": datasets.Value("int32"), | |
} | |
), | |
reference_urls=["https://scikit-learn.org/stable/modules/generated/sklearn.metrics.precision_score.html"], | |
) | |
def _compute( | |
self, | |
predictions, | |
references, | |
labels=None, | |
pos_label=1, | |
average="binary", | |
sample_weight=None, | |
zero_division="warn", | |
): | |
score = precision_score( | |
references, | |
predictions, | |
labels=labels, | |
pos_label=pos_label, | |
average=average, | |
sample_weight=sample_weight, | |
zero_division=zero_division, | |
) | |
return {"precision": float(score) if score.size == 1 else score} | |