Traktor/myenv/Lib/site-packages/sklearn/metrics/tests/test_common.py
2024-05-26 05:12:46 +02:00

1878 lines
60 KiB
Python

from functools import partial
from inspect import signature
from itertools import chain, permutations, product
import numpy as np
import pytest
from sklearn._config import config_context
from sklearn.datasets import make_multilabel_classification
from sklearn.metrics import (
accuracy_score,
average_precision_score,
balanced_accuracy_score,
brier_score_loss,
cohen_kappa_score,
confusion_matrix,
coverage_error,
d2_absolute_error_score,
d2_pinball_score,
d2_tweedie_score,
dcg_score,
det_curve,
explained_variance_score,
f1_score,
fbeta_score,
hamming_loss,
hinge_loss,
jaccard_score,
label_ranking_average_precision_score,
label_ranking_loss,
log_loss,
matthews_corrcoef,
max_error,
mean_absolute_error,
mean_absolute_percentage_error,
mean_gamma_deviance,
mean_pinball_loss,
mean_poisson_deviance,
mean_squared_error,
mean_tweedie_deviance,
median_absolute_error,
multilabel_confusion_matrix,
ndcg_score,
precision_recall_curve,
precision_score,
r2_score,
recall_score,
roc_auc_score,
roc_curve,
top_k_accuracy_score,
zero_one_loss,
)
from sklearn.metrics._base import _average_binary_score
from sklearn.preprocessing import LabelBinarizer
from sklearn.utils import shuffle
from sklearn.utils._array_api import (
_atol_for_type,
_convert_to_numpy,
yield_namespace_device_dtype_combinations,
)
from sklearn.utils._testing import (
_array_api_for_tests,
assert_allclose,
assert_almost_equal,
assert_array_equal,
assert_array_less,
ignore_warnings,
)
from sklearn.utils.fixes import COO_CONTAINERS
from sklearn.utils.multiclass import type_of_target
from sklearn.utils.validation import _num_samples, check_random_state
# Note toward developers about metric testing
# -------------------------------------------
# It is often possible to write one general test for several metrics:
#
# - invariance properties, e.g. invariance to sample order
# - common behavior for an argument, e.g. the "normalize" with value True
# will return the mean of the metrics and with value False will return
# the sum of the metrics.
#
# In order to improve the overall metric testing, it is a good idea to write
# first a specific test for the given metric and then add a general test for
# all metrics that have the same behavior.
#
# Two types of datastructures are used in order to implement this system:
# dictionaries of metrics and lists of metrics with common properties.
#
# Dictionaries of metrics
# ------------------------
# The goal of having those dictionaries is to have an easy way to call a
# particular metric and associate a name to each function:
#
# - REGRESSION_METRICS: all regression metrics.
# - CLASSIFICATION_METRICS: all classification metrics
# which compare a ground truth and the estimated targets as returned by a
# classifier.
# - THRESHOLDED_METRICS: all classification metrics which
# compare a ground truth and a score, e.g. estimated probabilities or
# decision function (format might vary)
#
# Those dictionaries will be used to test systematically some invariance
# properties, e.g. invariance toward several input layout.
#
REGRESSION_METRICS = {
"max_error": max_error,
"mean_absolute_error": mean_absolute_error,
"mean_squared_error": mean_squared_error,
"mean_pinball_loss": mean_pinball_loss,
"median_absolute_error": median_absolute_error,
"mean_absolute_percentage_error": mean_absolute_percentage_error,
"explained_variance_score": explained_variance_score,
"r2_score": partial(r2_score, multioutput="variance_weighted"),
"mean_normal_deviance": partial(mean_tweedie_deviance, power=0),
"mean_poisson_deviance": mean_poisson_deviance,
"mean_gamma_deviance": mean_gamma_deviance,
"mean_compound_poisson_deviance": partial(mean_tweedie_deviance, power=1.4),
"d2_tweedie_score": partial(d2_tweedie_score, power=1.4),
"d2_pinball_score": d2_pinball_score,
"d2_absolute_error_score": d2_absolute_error_score,
}
CLASSIFICATION_METRICS = {
"accuracy_score": accuracy_score,
"balanced_accuracy_score": balanced_accuracy_score,
"adjusted_balanced_accuracy_score": partial(balanced_accuracy_score, adjusted=True),
"unnormalized_accuracy_score": partial(accuracy_score, normalize=False),
# `confusion_matrix` returns absolute values and hence behaves unnormalized
# . Naming it with an unnormalized_ prefix is necessary for this module to
# skip sample_weight scaling checks which will fail for unnormalized
# metrics.
"unnormalized_confusion_matrix": confusion_matrix,
"normalized_confusion_matrix": lambda *args, **kwargs: (
confusion_matrix(*args, **kwargs).astype("float")
/ confusion_matrix(*args, **kwargs).sum(axis=1)[:, np.newaxis]
),
"unnormalized_multilabel_confusion_matrix": multilabel_confusion_matrix,
"unnormalized_multilabel_confusion_matrix_sample": partial(
multilabel_confusion_matrix, samplewise=True
),
"hamming_loss": hamming_loss,
"zero_one_loss": zero_one_loss,
"unnormalized_zero_one_loss": partial(zero_one_loss, normalize=False),
# These are needed to test averaging
"jaccard_score": jaccard_score,
"precision_score": precision_score,
"recall_score": recall_score,
"f1_score": f1_score,
"f2_score": partial(fbeta_score, beta=2),
"f0.5_score": partial(fbeta_score, beta=0.5),
"matthews_corrcoef_score": matthews_corrcoef,
"weighted_f0.5_score": partial(fbeta_score, average="weighted", beta=0.5),
"weighted_f1_score": partial(f1_score, average="weighted"),
"weighted_f2_score": partial(fbeta_score, average="weighted", beta=2),
"weighted_precision_score": partial(precision_score, average="weighted"),
"weighted_recall_score": partial(recall_score, average="weighted"),
"weighted_jaccard_score": partial(jaccard_score, average="weighted"),
"micro_f0.5_score": partial(fbeta_score, average="micro", beta=0.5),
"micro_f1_score": partial(f1_score, average="micro"),
"micro_f2_score": partial(fbeta_score, average="micro", beta=2),
"micro_precision_score": partial(precision_score, average="micro"),
"micro_recall_score": partial(recall_score, average="micro"),
"micro_jaccard_score": partial(jaccard_score, average="micro"),
"macro_f0.5_score": partial(fbeta_score, average="macro", beta=0.5),
"macro_f1_score": partial(f1_score, average="macro"),
"macro_f2_score": partial(fbeta_score, average="macro", beta=2),
"macro_precision_score": partial(precision_score, average="macro"),
"macro_recall_score": partial(recall_score, average="macro"),
"macro_jaccard_score": partial(jaccard_score, average="macro"),
"samples_f0.5_score": partial(fbeta_score, average="samples", beta=0.5),
"samples_f1_score": partial(f1_score, average="samples"),
"samples_f2_score": partial(fbeta_score, average="samples", beta=2),
"samples_precision_score": partial(precision_score, average="samples"),
"samples_recall_score": partial(recall_score, average="samples"),
"samples_jaccard_score": partial(jaccard_score, average="samples"),
"cohen_kappa_score": cohen_kappa_score,
}
def precision_recall_curve_padded_thresholds(*args, **kwargs):
"""
The dimensions of precision-recall pairs and the threshold array as
returned by the precision_recall_curve do not match. See
func:`sklearn.metrics.precision_recall_curve`
This prevents implicit conversion of return value triple to an higher
dimensional np.array of dtype('float64') (it will be of dtype('object)
instead). This again is needed for assert_array_equal to work correctly.
As a workaround we pad the threshold array with NaN values to match
the dimension of precision and recall arrays respectively.
"""
precision, recall, thresholds = precision_recall_curve(*args, **kwargs)
pad_threshholds = len(precision) - len(thresholds)
return np.array(
[
precision,
recall,
np.pad(
thresholds.astype(np.float64),
pad_width=(0, pad_threshholds),
mode="constant",
constant_values=[np.nan],
),
]
)
CURVE_METRICS = {
"roc_curve": roc_curve,
"precision_recall_curve": precision_recall_curve_padded_thresholds,
"det_curve": det_curve,
}
THRESHOLDED_METRICS = {
"coverage_error": coverage_error,
"label_ranking_loss": label_ranking_loss,
"log_loss": log_loss,
"unnormalized_log_loss": partial(log_loss, normalize=False),
"hinge_loss": hinge_loss,
"brier_score_loss": brier_score_loss,
"roc_auc_score": roc_auc_score, # default: average="macro"
"weighted_roc_auc": partial(roc_auc_score, average="weighted"),
"samples_roc_auc": partial(roc_auc_score, average="samples"),
"micro_roc_auc": partial(roc_auc_score, average="micro"),
"ovr_roc_auc": partial(roc_auc_score, average="macro", multi_class="ovr"),
"weighted_ovr_roc_auc": partial(
roc_auc_score, average="weighted", multi_class="ovr"
),
"ovo_roc_auc": partial(roc_auc_score, average="macro", multi_class="ovo"),
"weighted_ovo_roc_auc": partial(
roc_auc_score, average="weighted", multi_class="ovo"
),
"partial_roc_auc": partial(roc_auc_score, max_fpr=0.5),
"average_precision_score": average_precision_score, # default: average="macro"
"weighted_average_precision_score": partial(
average_precision_score, average="weighted"
),
"samples_average_precision_score": partial(
average_precision_score, average="samples"
),
"micro_average_precision_score": partial(average_precision_score, average="micro"),
"label_ranking_average_precision_score": label_ranking_average_precision_score,
"ndcg_score": ndcg_score,
"dcg_score": dcg_score,
"top_k_accuracy_score": top_k_accuracy_score,
}
ALL_METRICS = dict()
ALL_METRICS.update(THRESHOLDED_METRICS)
ALL_METRICS.update(CLASSIFICATION_METRICS)
ALL_METRICS.update(REGRESSION_METRICS)
ALL_METRICS.update(CURVE_METRICS)
# Lists of metrics with common properties
# ---------------------------------------
# Lists of metrics with common properties are used to test systematically some
# functionalities and invariance, e.g. SYMMETRIC_METRICS lists all metrics that
# are symmetric with respect to their input argument y_true and y_pred.
#
# When you add a new metric or functionality, check if a general test
# is already written.
# Those metrics don't support binary inputs
METRIC_UNDEFINED_BINARY = {
"samples_f0.5_score",
"samples_f1_score",
"samples_f2_score",
"samples_precision_score",
"samples_recall_score",
"samples_jaccard_score",
"coverage_error",
"unnormalized_multilabel_confusion_matrix_sample",
"label_ranking_loss",
"label_ranking_average_precision_score",
"dcg_score",
"ndcg_score",
}
# Those metrics don't support multiclass inputs
METRIC_UNDEFINED_MULTICLASS = {
"brier_score_loss",
"micro_roc_auc",
"samples_roc_auc",
"partial_roc_auc",
"roc_auc_score",
"weighted_roc_auc",
"jaccard_score",
# with default average='binary', multiclass is prohibited
"precision_score",
"recall_score",
"f1_score",
"f2_score",
"f0.5_score",
# curves
"roc_curve",
"precision_recall_curve",
"det_curve",
}
# Metric undefined with "binary" or "multiclass" input
METRIC_UNDEFINED_BINARY_MULTICLASS = METRIC_UNDEFINED_BINARY.union(
METRIC_UNDEFINED_MULTICLASS
)
# Metrics with an "average" argument
METRICS_WITH_AVERAGING = {
"precision_score",
"recall_score",
"f1_score",
"f2_score",
"f0.5_score",
"jaccard_score",
}
# Threshold-based metrics with an "average" argument
THRESHOLDED_METRICS_WITH_AVERAGING = {
"roc_auc_score",
"average_precision_score",
"partial_roc_auc",
}
# Metrics with a "pos_label" argument
METRICS_WITH_POS_LABEL = {
"roc_curve",
"precision_recall_curve",
"det_curve",
"brier_score_loss",
"precision_score",
"recall_score",
"f1_score",
"f2_score",
"f0.5_score",
"jaccard_score",
"average_precision_score",
"weighted_average_precision_score",
"micro_average_precision_score",
"samples_average_precision_score",
}
# Metrics with a "labels" argument
# TODO: Handle multi_class metrics that has a labels argument as well as a
# decision function argument. e.g hinge_loss
METRICS_WITH_LABELS = {
"unnormalized_confusion_matrix",
"normalized_confusion_matrix",
"roc_curve",
"precision_recall_curve",
"det_curve",
"precision_score",
"recall_score",
"f1_score",
"f2_score",
"f0.5_score",
"jaccard_score",
"weighted_f0.5_score",
"weighted_f1_score",
"weighted_f2_score",
"weighted_precision_score",
"weighted_recall_score",
"weighted_jaccard_score",
"micro_f0.5_score",
"micro_f1_score",
"micro_f2_score",
"micro_precision_score",
"micro_recall_score",
"micro_jaccard_score",
"macro_f0.5_score",
"macro_f1_score",
"macro_f2_score",
"macro_precision_score",
"macro_recall_score",
"macro_jaccard_score",
"unnormalized_multilabel_confusion_matrix",
"unnormalized_multilabel_confusion_matrix_sample",
"cohen_kappa_score",
}
# Metrics with a "normalize" option
METRICS_WITH_NORMALIZE_OPTION = {
"accuracy_score",
"top_k_accuracy_score",
"zero_one_loss",
}
# Threshold-based metrics with "multilabel-indicator" format support
THRESHOLDED_MULTILABEL_METRICS = {
"log_loss",
"unnormalized_log_loss",
"roc_auc_score",
"weighted_roc_auc",
"samples_roc_auc",
"micro_roc_auc",
"partial_roc_auc",
"average_precision_score",
"weighted_average_precision_score",
"samples_average_precision_score",
"micro_average_precision_score",
"coverage_error",
"label_ranking_loss",
"ndcg_score",
"dcg_score",
"label_ranking_average_precision_score",
}
# Classification metrics with "multilabel-indicator" format
MULTILABELS_METRICS = {
"accuracy_score",
"unnormalized_accuracy_score",
"hamming_loss",
"zero_one_loss",
"unnormalized_zero_one_loss",
"weighted_f0.5_score",
"weighted_f1_score",
"weighted_f2_score",
"weighted_precision_score",
"weighted_recall_score",
"weighted_jaccard_score",
"macro_f0.5_score",
"macro_f1_score",
"macro_f2_score",
"macro_precision_score",
"macro_recall_score",
"macro_jaccard_score",
"micro_f0.5_score",
"micro_f1_score",
"micro_f2_score",
"micro_precision_score",
"micro_recall_score",
"micro_jaccard_score",
"unnormalized_multilabel_confusion_matrix",
"samples_f0.5_score",
"samples_f1_score",
"samples_f2_score",
"samples_precision_score",
"samples_recall_score",
"samples_jaccard_score",
}
# Regression metrics with "multioutput-continuous" format support
MULTIOUTPUT_METRICS = {
"mean_absolute_error",
"median_absolute_error",
"mean_squared_error",
"r2_score",
"explained_variance_score",
"mean_absolute_percentage_error",
"mean_pinball_loss",
"d2_pinball_score",
"d2_absolute_error_score",
}
# Symmetric with respect to their input arguments y_true and y_pred
# metric(y_true, y_pred) == metric(y_pred, y_true).
SYMMETRIC_METRICS = {
"accuracy_score",
"unnormalized_accuracy_score",
"hamming_loss",
"zero_one_loss",
"unnormalized_zero_one_loss",
"micro_jaccard_score",
"macro_jaccard_score",
"jaccard_score",
"samples_jaccard_score",
"f1_score",
"micro_f1_score",
"macro_f1_score",
"weighted_recall_score",
# P = R = F = accuracy in multiclass case
"micro_f0.5_score",
"micro_f1_score",
"micro_f2_score",
"micro_precision_score",
"micro_recall_score",
"matthews_corrcoef_score",
"mean_absolute_error",
"mean_squared_error",
"median_absolute_error",
"max_error",
# Pinball loss is only symmetric for alpha=0.5 which is the default.
"mean_pinball_loss",
"cohen_kappa_score",
"mean_normal_deviance",
}
# Asymmetric with respect to their input arguments y_true and y_pred
# metric(y_true, y_pred) != metric(y_pred, y_true).
NOT_SYMMETRIC_METRICS = {
"balanced_accuracy_score",
"adjusted_balanced_accuracy_score",
"explained_variance_score",
"r2_score",
"unnormalized_confusion_matrix",
"normalized_confusion_matrix",
"roc_curve",
"precision_recall_curve",
"det_curve",
"precision_score",
"recall_score",
"f2_score",
"f0.5_score",
"weighted_f0.5_score",
"weighted_f1_score",
"weighted_f2_score",
"weighted_precision_score",
"weighted_jaccard_score",
"unnormalized_multilabel_confusion_matrix",
"macro_f0.5_score",
"macro_f2_score",
"macro_precision_score",
"macro_recall_score",
"hinge_loss",
"mean_gamma_deviance",
"mean_poisson_deviance",
"mean_compound_poisson_deviance",
"d2_tweedie_score",
"d2_pinball_score",
"d2_absolute_error_score",
"mean_absolute_percentage_error",
}
# No Sample weight support
METRICS_WITHOUT_SAMPLE_WEIGHT = {
"median_absolute_error",
"max_error",
"ovo_roc_auc",
"weighted_ovo_roc_auc",
}
METRICS_REQUIRE_POSITIVE_Y = {
"mean_poisson_deviance",
"mean_gamma_deviance",
"mean_compound_poisson_deviance",
"d2_tweedie_score",
}
def _require_positive_targets(y1, y2):
"""Make targets strictly positive"""
offset = abs(min(y1.min(), y2.min())) + 1
y1 += offset
y2 += offset
return y1, y2
def test_symmetry_consistency():
# We shouldn't forget any metrics
assert (
SYMMETRIC_METRICS
| NOT_SYMMETRIC_METRICS
| set(THRESHOLDED_METRICS)
| METRIC_UNDEFINED_BINARY_MULTICLASS
) == set(ALL_METRICS)
assert (SYMMETRIC_METRICS & NOT_SYMMETRIC_METRICS) == set()
@pytest.mark.parametrize("name", sorted(SYMMETRIC_METRICS))
def test_symmetric_metric(name):
# Test the symmetry of score and loss functions
random_state = check_random_state(0)
y_true = random_state.randint(0, 2, size=(20,))
y_pred = random_state.randint(0, 2, size=(20,))
if name in METRICS_REQUIRE_POSITIVE_Y:
y_true, y_pred = _require_positive_targets(y_true, y_pred)
y_true_bin = random_state.randint(0, 2, size=(20, 25))
y_pred_bin = random_state.randint(0, 2, size=(20, 25))
metric = ALL_METRICS[name]
if name in METRIC_UNDEFINED_BINARY:
if name in MULTILABELS_METRICS:
assert_allclose(
metric(y_true_bin, y_pred_bin),
metric(y_pred_bin, y_true_bin),
err_msg="%s is not symmetric" % name,
)
else:
assert False, "This case is currently unhandled"
else:
assert_allclose(
metric(y_true, y_pred),
metric(y_pred, y_true),
err_msg="%s is not symmetric" % name,
)
@pytest.mark.parametrize("name", sorted(NOT_SYMMETRIC_METRICS))
def test_not_symmetric_metric(name):
# Test the symmetry of score and loss functions
random_state = check_random_state(0)
y_true = random_state.randint(0, 2, size=(20,))
y_pred = random_state.randint(0, 2, size=(20,))
if name in METRICS_REQUIRE_POSITIVE_Y:
y_true, y_pred = _require_positive_targets(y_true, y_pred)
metric = ALL_METRICS[name]
# use context manager to supply custom error message
with pytest.raises(AssertionError):
assert_array_equal(metric(y_true, y_pred), metric(y_pred, y_true))
raise ValueError("%s seems to be symmetric" % name)
@pytest.mark.parametrize(
"name", sorted(set(ALL_METRICS) - METRIC_UNDEFINED_BINARY_MULTICLASS)
)
def test_sample_order_invariance(name):
random_state = check_random_state(0)
y_true = random_state.randint(0, 2, size=(20,))
y_pred = random_state.randint(0, 2, size=(20,))
if name in METRICS_REQUIRE_POSITIVE_Y:
y_true, y_pred = _require_positive_targets(y_true, y_pred)
y_true_shuffle, y_pred_shuffle = shuffle(y_true, y_pred, random_state=0)
with ignore_warnings():
metric = ALL_METRICS[name]
assert_allclose(
metric(y_true, y_pred),
metric(y_true_shuffle, y_pred_shuffle),
err_msg="%s is not sample order invariant" % name,
)
@ignore_warnings
def test_sample_order_invariance_multilabel_and_multioutput():
random_state = check_random_state(0)
# Generate some data
y_true = random_state.randint(0, 2, size=(20, 25))
y_pred = random_state.randint(0, 2, size=(20, 25))
y_score = random_state.uniform(size=y_true.shape)
# Some metrics (e.g. log_loss) require y_score to be probabilities (sum to 1)
y_score /= y_score.sum(axis=1, keepdims=True)
y_true_shuffle, y_pred_shuffle, y_score_shuffle = shuffle(
y_true, y_pred, y_score, random_state=0
)
for name in MULTILABELS_METRICS:
metric = ALL_METRICS[name]
assert_allclose(
metric(y_true, y_pred),
metric(y_true_shuffle, y_pred_shuffle),
err_msg="%s is not sample order invariant" % name,
)
for name in THRESHOLDED_MULTILABEL_METRICS:
metric = ALL_METRICS[name]
assert_allclose(
metric(y_true, y_score),
metric(y_true_shuffle, y_score_shuffle),
err_msg="%s is not sample order invariant" % name,
)
for name in MULTIOUTPUT_METRICS:
metric = ALL_METRICS[name]
assert_allclose(
metric(y_true, y_score),
metric(y_true_shuffle, y_score_shuffle),
err_msg="%s is not sample order invariant" % name,
)
assert_allclose(
metric(y_true, y_pred),
metric(y_true_shuffle, y_pred_shuffle),
err_msg="%s is not sample order invariant" % name,
)
@pytest.mark.parametrize(
"name", sorted(set(ALL_METRICS) - METRIC_UNDEFINED_BINARY_MULTICLASS)
)
def test_format_invariance_with_1d_vectors(name):
random_state = check_random_state(0)
y1 = random_state.randint(0, 2, size=(20,))
y2 = random_state.randint(0, 2, size=(20,))
if name in METRICS_REQUIRE_POSITIVE_Y:
y1, y2 = _require_positive_targets(y1, y2)
y1_list = list(y1)
y2_list = list(y2)
y1_1d, y2_1d = np.array(y1), np.array(y2)
assert_array_equal(y1_1d.ndim, 1)
assert_array_equal(y2_1d.ndim, 1)
y1_column = np.reshape(y1_1d, (-1, 1))
y2_column = np.reshape(y2_1d, (-1, 1))
y1_row = np.reshape(y1_1d, (1, -1))
y2_row = np.reshape(y2_1d, (1, -1))
with ignore_warnings():
metric = ALL_METRICS[name]
measure = metric(y1, y2)
assert_allclose(
metric(y1_list, y2_list),
measure,
err_msg="%s is not representation invariant with list" % name,
)
assert_allclose(
metric(y1_1d, y2_1d),
measure,
err_msg="%s is not representation invariant with np-array-1d" % name,
)
assert_allclose(
metric(y1_column, y2_column),
measure,
err_msg="%s is not representation invariant with np-array-column" % name,
)
# Mix format support
assert_allclose(
metric(y1_1d, y2_list),
measure,
err_msg="%s is not representation invariant with mix np-array-1d and list"
% name,
)
assert_allclose(
metric(y1_list, y2_1d),
measure,
err_msg="%s is not representation invariant with mix np-array-1d and list"
% name,
)
assert_allclose(
metric(y1_1d, y2_column),
measure,
err_msg=(
"%s is not representation invariant with mix "
"np-array-1d and np-array-column"
)
% name,
)
assert_allclose(
metric(y1_column, y2_1d),
measure,
err_msg=(
"%s is not representation invariant with mix "
"np-array-1d and np-array-column"
)
% name,
)
assert_allclose(
metric(y1_list, y2_column),
measure,
err_msg=(
"%s is not representation invariant with mix list and np-array-column"
)
% name,
)
assert_allclose(
metric(y1_column, y2_list),
measure,
err_msg=(
"%s is not representation invariant with mix list and np-array-column"
)
% name,
)
# These mix representations aren't allowed
with pytest.raises(ValueError):
metric(y1_1d, y2_row)
with pytest.raises(ValueError):
metric(y1_row, y2_1d)
with pytest.raises(ValueError):
metric(y1_list, y2_row)
with pytest.raises(ValueError):
metric(y1_row, y2_list)
with pytest.raises(ValueError):
metric(y1_column, y2_row)
with pytest.raises(ValueError):
metric(y1_row, y2_column)
# NB: We do not test for y1_row, y2_row as these may be
# interpreted as multilabel or multioutput data.
if name not in (
MULTIOUTPUT_METRICS | THRESHOLDED_MULTILABEL_METRICS | MULTILABELS_METRICS
):
with pytest.raises(ValueError):
metric(y1_row, y2_row)
@pytest.mark.parametrize(
"name", sorted(set(CLASSIFICATION_METRICS) - METRIC_UNDEFINED_BINARY_MULTICLASS)
)
def test_classification_invariance_string_vs_numbers_labels(name):
# Ensure that classification metrics with string labels are invariant
random_state = check_random_state(0)
y1 = random_state.randint(0, 2, size=(20,))
y2 = random_state.randint(0, 2, size=(20,))
y1_str = np.array(["eggs", "spam"])[y1]
y2_str = np.array(["eggs", "spam"])[y2]
pos_label_str = "spam"
labels_str = ["eggs", "spam"]
with ignore_warnings():
metric = CLASSIFICATION_METRICS[name]
measure_with_number = metric(y1, y2)
# Ugly, but handle case with a pos_label and label
metric_str = metric
if name in METRICS_WITH_POS_LABEL:
metric_str = partial(metric_str, pos_label=pos_label_str)
measure_with_str = metric_str(y1_str, y2_str)
assert_array_equal(
measure_with_number,
measure_with_str,
err_msg="{0} failed string vs number invariance test".format(name),
)
measure_with_strobj = metric_str(y1_str.astype("O"), y2_str.astype("O"))
assert_array_equal(
measure_with_number,
measure_with_strobj,
err_msg="{0} failed string object vs number invariance test".format(name),
)
if name in METRICS_WITH_LABELS:
metric_str = partial(metric_str, labels=labels_str)
measure_with_str = metric_str(y1_str, y2_str)
assert_array_equal(
measure_with_number,
measure_with_str,
err_msg="{0} failed string vs number invariance test".format(name),
)
measure_with_strobj = metric_str(y1_str.astype("O"), y2_str.astype("O"))
assert_array_equal(
measure_with_number,
measure_with_strobj,
err_msg="{0} failed string vs number invariance test".format(name),
)
@pytest.mark.parametrize("name", THRESHOLDED_METRICS)
def test_thresholded_invariance_string_vs_numbers_labels(name):
# Ensure that thresholded metrics with string labels are invariant
random_state = check_random_state(0)
y1 = random_state.randint(0, 2, size=(20,))
y2 = random_state.randint(0, 2, size=(20,))
y1_str = np.array(["eggs", "spam"])[y1]
pos_label_str = "spam"
with ignore_warnings():
metric = THRESHOLDED_METRICS[name]
if name not in METRIC_UNDEFINED_BINARY:
# Ugly, but handle case with a pos_label and label
metric_str = metric
if name in METRICS_WITH_POS_LABEL:
metric_str = partial(metric_str, pos_label=pos_label_str)
measure_with_number = metric(y1, y2)
measure_with_str = metric_str(y1_str, y2)
assert_array_equal(
measure_with_number,
measure_with_str,
err_msg="{0} failed string vs number invariance test".format(name),
)
measure_with_strobj = metric_str(y1_str.astype("O"), y2)
assert_array_equal(
measure_with_number,
measure_with_strobj,
err_msg="{0} failed string object vs number invariance test".format(
name
),
)
else:
# TODO those metrics doesn't support string label yet
with pytest.raises(ValueError):
metric(y1_str, y2)
with pytest.raises(ValueError):
metric(y1_str.astype("O"), y2)
invalids_nan_inf = [
([0, 1], [np.inf, np.inf]),
([0, 1], [np.nan, np.nan]),
([0, 1], [np.nan, np.inf]),
([0, 1], [np.inf, 1]),
([0, 1], [np.nan, 1]),
]
@pytest.mark.parametrize(
"metric", chain(THRESHOLDED_METRICS.values(), REGRESSION_METRICS.values())
)
@pytest.mark.parametrize("y_true, y_score", invalids_nan_inf)
def test_regression_thresholded_inf_nan_input(metric, y_true, y_score):
# Reshape since coverage_error only accepts 2D arrays.
if metric == coverage_error:
y_true = [y_true]
y_score = [y_score]
with pytest.raises(ValueError, match=r"contains (NaN|infinity)"):
metric(y_true, y_score)
@pytest.mark.parametrize("metric", CLASSIFICATION_METRICS.values())
@pytest.mark.parametrize(
"y_true, y_score",
invalids_nan_inf +
# Add an additional case for classification only
# non-regression test for:
# https://github.com/scikit-learn/scikit-learn/issues/6809
[
([np.nan, 1, 2], [1, 2, 3]),
([np.inf, 1, 2], [1, 2, 3]),
], # type: ignore
)
def test_classification_inf_nan_input(metric, y_true, y_score):
"""check that classification metrics raise a message mentioning the
occurrence of non-finite values in the target vectors."""
if not np.isfinite(y_true).all():
input_name = "y_true"
if np.isnan(y_true).any():
unexpected_value = "NaN"
else:
unexpected_value = "infinity or a value too large"
else:
input_name = "y_pred"
if np.isnan(y_score).any():
unexpected_value = "NaN"
else:
unexpected_value = "infinity or a value too large"
err_msg = f"Input {input_name} contains {unexpected_value}"
with pytest.raises(ValueError, match=err_msg):
metric(y_true, y_score)
@pytest.mark.parametrize("metric", CLASSIFICATION_METRICS.values())
def test_classification_binary_continuous_input(metric):
"""check that classification metrics raise a message of mixed type data
with continuous/binary target vectors."""
y_true, y_score = ["a", "b", "a"], [0.1, 0.2, 0.3]
err_msg = (
"Classification metrics can't handle a mix of binary and continuous targets"
)
with pytest.raises(ValueError, match=err_msg):
metric(y_true, y_score)
@ignore_warnings
def check_single_sample(name):
# Non-regression test: scores should work with a single sample.
# This is important for leave-one-out cross validation.
# Score functions tested are those that formerly called np.squeeze,
# which turns an array of size 1 into a 0-d array (!).
metric = ALL_METRICS[name]
# assert that no exception is thrown
if name in METRICS_REQUIRE_POSITIVE_Y:
values = [1, 2]
else:
values = [0, 1]
for i, j in product(values, repeat=2):
metric([i], [j])
@ignore_warnings
def check_single_sample_multioutput(name):
metric = ALL_METRICS[name]
for i, j, k, l in product([0, 1], repeat=4):
metric(np.array([[i, j]]), np.array([[k, l]]))
@pytest.mark.parametrize(
"name",
sorted(
set(ALL_METRICS)
# Those metrics are not always defined with one sample
# or in multiclass classification
- METRIC_UNDEFINED_BINARY_MULTICLASS
- set(THRESHOLDED_METRICS)
),
)
def test_single_sample(name):
check_single_sample(name)
@pytest.mark.parametrize("name", sorted(MULTIOUTPUT_METRICS | MULTILABELS_METRICS))
def test_single_sample_multioutput(name):
check_single_sample_multioutput(name)
@pytest.mark.parametrize("name", sorted(MULTIOUTPUT_METRICS))
def test_multioutput_number_of_output_differ(name):
y_true = np.array([[1, 0, 0, 1], [0, 1, 1, 1], [1, 1, 0, 1]])
y_pred = np.array([[0, 0], [1, 0], [0, 0]])
metric = ALL_METRICS[name]
with pytest.raises(ValueError):
metric(y_true, y_pred)
@pytest.mark.parametrize("name", sorted(MULTIOUTPUT_METRICS))
def test_multioutput_regression_invariance_to_dimension_shuffling(name):
# test invariance to dimension shuffling
random_state = check_random_state(0)
y_true = random_state.uniform(0, 2, size=(20, 5))
y_pred = random_state.uniform(0, 2, size=(20, 5))
metric = ALL_METRICS[name]
error = metric(y_true, y_pred)
for _ in range(3):
perm = random_state.permutation(y_true.shape[1])
assert_allclose(
metric(y_true[:, perm], y_pred[:, perm]),
error,
err_msg="%s is not dimension shuffling invariant" % (name),
)
@ignore_warnings
@pytest.mark.parametrize("coo_container", COO_CONTAINERS)
def test_multilabel_representation_invariance(coo_container):
# Generate some data
n_classes = 4
n_samples = 50
_, y1 = make_multilabel_classification(
n_features=1,
n_classes=n_classes,
random_state=0,
n_samples=n_samples,
allow_unlabeled=True,
)
_, y2 = make_multilabel_classification(
n_features=1,
n_classes=n_classes,
random_state=1,
n_samples=n_samples,
allow_unlabeled=True,
)
# To make sure at least one empty label is present
y1 = np.vstack([y1, [[0] * n_classes]])
y2 = np.vstack([y2, [[0] * n_classes]])
y1_sparse_indicator = coo_container(y1)
y2_sparse_indicator = coo_container(y2)
y1_list_array_indicator = list(y1)
y2_list_array_indicator = list(y2)
y1_list_list_indicator = [list(a) for a in y1_list_array_indicator]
y2_list_list_indicator = [list(a) for a in y2_list_array_indicator]
for name in MULTILABELS_METRICS:
metric = ALL_METRICS[name]
# XXX cruel hack to work with partial functions
if isinstance(metric, partial):
metric.__module__ = "tmp"
metric.__name__ = name
measure = metric(y1, y2)
# Check representation invariance
assert_allclose(
metric(y1_sparse_indicator, y2_sparse_indicator),
measure,
err_msg=(
"%s failed representation invariance between "
"dense and sparse indicator formats."
)
% name,
)
assert_almost_equal(
metric(y1_list_list_indicator, y2_list_list_indicator),
measure,
err_msg=(
"%s failed representation invariance "
"between dense array and list of list "
"indicator formats."
)
% name,
)
assert_almost_equal(
metric(y1_list_array_indicator, y2_list_array_indicator),
measure,
err_msg=(
"%s failed representation invariance "
"between dense and list of array "
"indicator formats."
)
% name,
)
@pytest.mark.parametrize("name", sorted(MULTILABELS_METRICS))
def test_raise_value_error_multilabel_sequences(name):
# make sure the multilabel-sequence format raises ValueError
multilabel_sequences = [
[[1], [2], [0, 1]],
[(), (2), (0, 1)],
[[]],
[()],
np.array([[], [1, 2]], dtype="object"),
]
metric = ALL_METRICS[name]
for seq in multilabel_sequences:
with pytest.raises(ValueError):
metric(seq, seq)
@pytest.mark.parametrize("name", sorted(METRICS_WITH_NORMALIZE_OPTION))
def test_normalize_option_binary_classification(name):
# Test in the binary case
n_classes = 2
n_samples = 20
random_state = check_random_state(0)
y_true = random_state.randint(0, n_classes, size=(n_samples,))
y_pred = random_state.randint(0, n_classes, size=(n_samples,))
y_score = random_state.normal(size=y_true.shape)
metrics = ALL_METRICS[name]
pred = y_score if name in THRESHOLDED_METRICS else y_pred
measure_normalized = metrics(y_true, pred, normalize=True)
measure_not_normalized = metrics(y_true, pred, normalize=False)
assert_array_less(
-1.0 * measure_normalized,
0,
err_msg="We failed to test correctly the normalize option",
)
assert_allclose(
measure_normalized,
measure_not_normalized / n_samples,
err_msg=f"Failed with {name}",
)
@pytest.mark.parametrize("name", sorted(METRICS_WITH_NORMALIZE_OPTION))
def test_normalize_option_multiclass_classification(name):
# Test in the multiclass case
n_classes = 4
n_samples = 20
random_state = check_random_state(0)
y_true = random_state.randint(0, n_classes, size=(n_samples,))
y_pred = random_state.randint(0, n_classes, size=(n_samples,))
y_score = random_state.uniform(size=(n_samples, n_classes))
metrics = ALL_METRICS[name]
pred = y_score if name in THRESHOLDED_METRICS else y_pred
measure_normalized = metrics(y_true, pred, normalize=True)
measure_not_normalized = metrics(y_true, pred, normalize=False)
assert_array_less(
-1.0 * measure_normalized,
0,
err_msg="We failed to test correctly the normalize option",
)
assert_allclose(
measure_normalized,
measure_not_normalized / n_samples,
err_msg=f"Failed with {name}",
)
@pytest.mark.parametrize(
"name", sorted(METRICS_WITH_NORMALIZE_OPTION.intersection(MULTILABELS_METRICS))
)
def test_normalize_option_multilabel_classification(name):
# Test in the multilabel case
n_classes = 4
n_samples = 100
random_state = check_random_state(0)
# for both random_state 0 and 1, y_true and y_pred has at least one
# unlabelled entry
_, y_true = make_multilabel_classification(
n_features=1,
n_classes=n_classes,
random_state=0,
allow_unlabeled=True,
n_samples=n_samples,
)
_, y_pred = make_multilabel_classification(
n_features=1,
n_classes=n_classes,
random_state=1,
allow_unlabeled=True,
n_samples=n_samples,
)
y_score = random_state.uniform(size=y_true.shape)
# To make sure at least one empty label is present
y_true += [0] * n_classes
y_pred += [0] * n_classes
metrics = ALL_METRICS[name]
pred = y_score if name in THRESHOLDED_METRICS else y_pred
measure_normalized = metrics(y_true, pred, normalize=True)
measure_not_normalized = metrics(y_true, pred, normalize=False)
assert_array_less(
-1.0 * measure_normalized,
0,
err_msg="We failed to test correctly the normalize option",
)
assert_allclose(
measure_normalized,
measure_not_normalized / n_samples,
err_msg=f"Failed with {name}",
)
@ignore_warnings
def _check_averaging(
metric, y_true, y_pred, y_true_binarize, y_pred_binarize, is_multilabel
):
n_samples, n_classes = y_true_binarize.shape
# No averaging
label_measure = metric(y_true, y_pred, average=None)
assert_allclose(
label_measure,
[
metric(y_true_binarize[:, i], y_pred_binarize[:, i])
for i in range(n_classes)
],
)
# Micro measure
micro_measure = metric(y_true, y_pred, average="micro")
assert_allclose(
micro_measure, metric(y_true_binarize.ravel(), y_pred_binarize.ravel())
)
# Macro measure
macro_measure = metric(y_true, y_pred, average="macro")
assert_allclose(macro_measure, np.mean(label_measure))
# Weighted measure
weights = np.sum(y_true_binarize, axis=0, dtype=int)
if np.sum(weights) != 0:
weighted_measure = metric(y_true, y_pred, average="weighted")
assert_allclose(weighted_measure, np.average(label_measure, weights=weights))
else:
weighted_measure = metric(y_true, y_pred, average="weighted")
assert_allclose(weighted_measure, 0)
# Sample measure
if is_multilabel:
sample_measure = metric(y_true, y_pred, average="samples")
assert_allclose(
sample_measure,
np.mean(
[
metric(y_true_binarize[i], y_pred_binarize[i])
for i in range(n_samples)
]
),
)
with pytest.raises(ValueError):
metric(y_true, y_pred, average="unknown")
with pytest.raises(ValueError):
metric(y_true, y_pred, average="garbage")
def check_averaging(name, y_true, y_true_binarize, y_pred, y_pred_binarize, y_score):
is_multilabel = type_of_target(y_true).startswith("multilabel")
metric = ALL_METRICS[name]
if name in METRICS_WITH_AVERAGING:
_check_averaging(
metric, y_true, y_pred, y_true_binarize, y_pred_binarize, is_multilabel
)
elif name in THRESHOLDED_METRICS_WITH_AVERAGING:
_check_averaging(
metric, y_true, y_score, y_true_binarize, y_score, is_multilabel
)
else:
raise ValueError("Metric is not recorded as having an average option")
@pytest.mark.parametrize("name", sorted(METRICS_WITH_AVERAGING))
def test_averaging_multiclass(name):
n_samples, n_classes = 50, 3
random_state = check_random_state(0)
y_true = random_state.randint(0, n_classes, size=(n_samples,))
y_pred = random_state.randint(0, n_classes, size=(n_samples,))
y_score = random_state.uniform(size=(n_samples, n_classes))
lb = LabelBinarizer().fit(y_true)
y_true_binarize = lb.transform(y_true)
y_pred_binarize = lb.transform(y_pred)
check_averaging(name, y_true, y_true_binarize, y_pred, y_pred_binarize, y_score)
@pytest.mark.parametrize(
"name", sorted(METRICS_WITH_AVERAGING | THRESHOLDED_METRICS_WITH_AVERAGING)
)
def test_averaging_multilabel(name):
n_samples, n_classes = 40, 5
_, y = make_multilabel_classification(
n_features=1,
n_classes=n_classes,
random_state=5,
n_samples=n_samples,
allow_unlabeled=False,
)
y_true = y[:20]
y_pred = y[20:]
y_score = check_random_state(0).normal(size=(20, n_classes))
y_true_binarize = y_true
y_pred_binarize = y_pred
check_averaging(name, y_true, y_true_binarize, y_pred, y_pred_binarize, y_score)
@pytest.mark.parametrize("name", sorted(METRICS_WITH_AVERAGING))
def test_averaging_multilabel_all_zeroes(name):
y_true = np.zeros((20, 3))
y_pred = np.zeros((20, 3))
y_score = np.zeros((20, 3))
y_true_binarize = y_true
y_pred_binarize = y_pred
check_averaging(name, y_true, y_true_binarize, y_pred, y_pred_binarize, y_score)
def test_averaging_binary_multilabel_all_zeroes():
y_true = np.zeros((20, 3))
y_pred = np.zeros((20, 3))
y_true_binarize = y_true
y_pred_binarize = y_pred
# Test _average_binary_score for weight.sum() == 0
binary_metric = lambda y_true, y_score, average="macro": _average_binary_score(
precision_score, y_true, y_score, average
)
_check_averaging(
binary_metric,
y_true,
y_pred,
y_true_binarize,
y_pred_binarize,
is_multilabel=True,
)
@pytest.mark.parametrize("name", sorted(METRICS_WITH_AVERAGING))
def test_averaging_multilabel_all_ones(name):
y_true = np.ones((20, 3))
y_pred = np.ones((20, 3))
y_score = np.ones((20, 3))
y_true_binarize = y_true
y_pred_binarize = y_pred
check_averaging(name, y_true, y_true_binarize, y_pred, y_pred_binarize, y_score)
@ignore_warnings
def check_sample_weight_invariance(name, metric, y1, y2):
rng = np.random.RandomState(0)
sample_weight = rng.randint(1, 10, size=len(y1))
# top_k_accuracy_score always lead to a perfect score for k > 1 in the
# binary case
metric = partial(metric, k=1) if name == "top_k_accuracy_score" else metric
# check that unit weights gives the same score as no weight
unweighted_score = metric(y1, y2, sample_weight=None)
assert_allclose(
unweighted_score,
metric(y1, y2, sample_weight=np.ones(shape=len(y1))),
err_msg="For %s sample_weight=None is not equivalent to sample_weight=ones"
% name,
)
# check that the weighted and unweighted scores are unequal
weighted_score = metric(y1, y2, sample_weight=sample_weight)
# use context manager to supply custom error message
with pytest.raises(AssertionError):
assert_allclose(unweighted_score, weighted_score)
raise ValueError(
"Unweighted and weighted scores are unexpectedly "
"almost equal (%s) and (%s) "
"for %s" % (unweighted_score, weighted_score, name)
)
# check that sample_weight can be a list
weighted_score_list = metric(y1, y2, sample_weight=sample_weight.tolist())
assert_allclose(
weighted_score,
weighted_score_list,
err_msg=(
"Weighted scores for array and list "
"sample_weight input are not equal (%s != %s) for %s"
)
% (weighted_score, weighted_score_list, name),
)
# check that integer weights is the same as repeated samples
repeat_weighted_score = metric(
np.repeat(y1, sample_weight, axis=0),
np.repeat(y2, sample_weight, axis=0),
sample_weight=None,
)
assert_allclose(
weighted_score,
repeat_weighted_score,
err_msg="Weighting %s is not equal to repeating samples" % name,
)
# check that ignoring a fraction of the samples is equivalent to setting
# the corresponding weights to zero
sample_weight_subset = sample_weight[1::2]
sample_weight_zeroed = np.copy(sample_weight)
sample_weight_zeroed[::2] = 0
y1_subset = y1[1::2]
y2_subset = y2[1::2]
weighted_score_subset = metric(
y1_subset, y2_subset, sample_weight=sample_weight_subset
)
weighted_score_zeroed = metric(y1, y2, sample_weight=sample_weight_zeroed)
assert_allclose(
weighted_score_subset,
weighted_score_zeroed,
err_msg=(
"Zeroing weights does not give the same result as "
"removing the corresponding samples (%s != %s) for %s"
)
% (weighted_score_zeroed, weighted_score_subset, name),
)
if not name.startswith("unnormalized"):
# check that the score is invariant under scaling of the weights by a
# common factor
for scaling in [2, 0.3]:
assert_allclose(
weighted_score,
metric(y1, y2, sample_weight=sample_weight * scaling),
err_msg="%s sample_weight is not invariant under scaling" % name,
)
# Check that if number of samples in y_true and sample_weight are not
# equal, meaningful error is raised.
error_message = (
r"Found input variables with inconsistent numbers of "
r"samples: \[{}, {}, {}\]".format(
_num_samples(y1), _num_samples(y2), _num_samples(sample_weight) * 2
)
)
with pytest.raises(ValueError, match=error_message):
metric(y1, y2, sample_weight=np.hstack([sample_weight, sample_weight]))
@pytest.mark.parametrize(
"name",
sorted(
set(ALL_METRICS).intersection(set(REGRESSION_METRICS))
- METRICS_WITHOUT_SAMPLE_WEIGHT
),
)
def test_regression_sample_weight_invariance(name):
n_samples = 50
random_state = check_random_state(0)
# regression
y_true = random_state.random_sample(size=(n_samples,))
y_pred = random_state.random_sample(size=(n_samples,))
metric = ALL_METRICS[name]
check_sample_weight_invariance(name, metric, y_true, y_pred)
@pytest.mark.parametrize(
"name",
sorted(
set(ALL_METRICS)
- set(REGRESSION_METRICS)
- METRICS_WITHOUT_SAMPLE_WEIGHT
- METRIC_UNDEFINED_BINARY
),
)
def test_binary_sample_weight_invariance(name):
# binary
n_samples = 50
random_state = check_random_state(0)
y_true = random_state.randint(0, 2, size=(n_samples,))
y_pred = random_state.randint(0, 2, size=(n_samples,))
y_score = random_state.random_sample(size=(n_samples,))
metric = ALL_METRICS[name]
if name in THRESHOLDED_METRICS:
check_sample_weight_invariance(name, metric, y_true, y_score)
else:
check_sample_weight_invariance(name, metric, y_true, y_pred)
@pytest.mark.parametrize(
"name",
sorted(
set(ALL_METRICS)
- set(REGRESSION_METRICS)
- METRICS_WITHOUT_SAMPLE_WEIGHT
- METRIC_UNDEFINED_BINARY_MULTICLASS
),
)
def test_multiclass_sample_weight_invariance(name):
# multiclass
n_samples = 50
random_state = check_random_state(0)
y_true = random_state.randint(0, 5, size=(n_samples,))
y_pred = random_state.randint(0, 5, size=(n_samples,))
y_score = random_state.random_sample(size=(n_samples, 5))
metric = ALL_METRICS[name]
if name in THRESHOLDED_METRICS:
# softmax
temp = np.exp(-y_score)
y_score_norm = temp / temp.sum(axis=-1).reshape(-1, 1)
check_sample_weight_invariance(name, metric, y_true, y_score_norm)
else:
check_sample_weight_invariance(name, metric, y_true, y_pred)
@pytest.mark.parametrize(
"name",
sorted(
(MULTILABELS_METRICS | THRESHOLDED_MULTILABEL_METRICS | MULTIOUTPUT_METRICS)
- METRICS_WITHOUT_SAMPLE_WEIGHT
),
)
def test_multilabel_sample_weight_invariance(name):
# multilabel indicator
random_state = check_random_state(0)
_, ya = make_multilabel_classification(
n_features=1, n_classes=10, random_state=0, n_samples=50, allow_unlabeled=False
)
_, yb = make_multilabel_classification(
n_features=1, n_classes=10, random_state=1, n_samples=50, allow_unlabeled=False
)
y_true = np.vstack([ya, yb])
y_pred = np.vstack([ya, ya])
y_score = random_state.uniform(size=y_true.shape)
# Some metrics (e.g. log_loss) require y_score to be probabilities (sum to 1)
y_score /= y_score.sum(axis=1, keepdims=True)
metric = ALL_METRICS[name]
if name in THRESHOLDED_METRICS:
check_sample_weight_invariance(name, metric, y_true, y_score)
else:
check_sample_weight_invariance(name, metric, y_true, y_pred)
@ignore_warnings
def test_no_averaging_labels():
# test labels argument when not using averaging
# in multi-class and multi-label cases
y_true_multilabel = np.array([[1, 1, 0, 0], [1, 1, 0, 0]])
y_pred_multilabel = np.array([[0, 0, 1, 1], [0, 1, 1, 0]])
y_true_multiclass = np.array([0, 1, 2])
y_pred_multiclass = np.array([0, 2, 3])
labels = np.array([3, 0, 1, 2])
_, inverse_labels = np.unique(labels, return_inverse=True)
for name in METRICS_WITH_AVERAGING:
for y_true, y_pred in [
[y_true_multiclass, y_pred_multiclass],
[y_true_multilabel, y_pred_multilabel],
]:
if name not in MULTILABELS_METRICS and y_pred.ndim > 1:
continue
metric = ALL_METRICS[name]
score_labels = metric(y_true, y_pred, labels=labels, average=None)
score = metric(y_true, y_pred, average=None)
assert_array_equal(score_labels, score[inverse_labels])
@pytest.mark.parametrize(
"name", sorted(MULTILABELS_METRICS - {"unnormalized_multilabel_confusion_matrix"})
)
def test_multilabel_label_permutations_invariance(name):
random_state = check_random_state(0)
n_samples, n_classes = 20, 4
y_true = random_state.randint(0, 2, size=(n_samples, n_classes))
y_score = random_state.randint(0, 2, size=(n_samples, n_classes))
metric = ALL_METRICS[name]
score = metric(y_true, y_score)
for perm in permutations(range(n_classes), n_classes):
y_score_perm = y_score[:, perm]
y_true_perm = y_true[:, perm]
current_score = metric(y_true_perm, y_score_perm)
assert_almost_equal(score, current_score)
@pytest.mark.parametrize(
"name", sorted(THRESHOLDED_MULTILABEL_METRICS | MULTIOUTPUT_METRICS)
)
def test_thresholded_multilabel_multioutput_permutations_invariance(name):
random_state = check_random_state(0)
n_samples, n_classes = 20, 4
y_true = random_state.randint(0, 2, size=(n_samples, n_classes))
y_score = random_state.uniform(size=y_true.shape)
# Some metrics (e.g. log_loss) require y_score to be probabilities (sum to 1)
y_score /= y_score.sum(axis=1, keepdims=True)
# Makes sure all samples have at least one label. This works around errors
# when running metrics where average="sample"
y_true[y_true.sum(1) == 4, 0] = 0
y_true[y_true.sum(1) == 0, 0] = 1
metric = ALL_METRICS[name]
score = metric(y_true, y_score)
for perm in permutations(range(n_classes), n_classes):
y_score_perm = y_score[:, perm]
y_true_perm = y_true[:, perm]
current_score = metric(y_true_perm, y_score_perm)
if metric == mean_absolute_percentage_error:
assert np.isfinite(current_score)
assert current_score > 1e6
# Here we are not comparing the values in case of MAPE because
# whenever y_true value is exactly zero, the MAPE value doesn't
# signify anything. Thus, in this case we are just expecting
# very large finite value.
else:
assert_almost_equal(score, current_score)
@pytest.mark.parametrize(
"name", sorted(set(THRESHOLDED_METRICS) - METRIC_UNDEFINED_BINARY_MULTICLASS)
)
def test_thresholded_metric_permutation_invariance(name):
n_samples, n_classes = 100, 3
random_state = check_random_state(0)
y_score = random_state.rand(n_samples, n_classes)
temp = np.exp(-y_score)
y_score = temp / temp.sum(axis=-1).reshape(-1, 1)
y_true = random_state.randint(0, n_classes, size=n_samples)
metric = ALL_METRICS[name]
score = metric(y_true, y_score)
for perm in permutations(range(n_classes), n_classes):
inverse_perm = np.zeros(n_classes, dtype=int)
inverse_perm[list(perm)] = np.arange(n_classes)
y_score_perm = y_score[:, inverse_perm]
y_true_perm = np.take(perm, y_true)
current_score = metric(y_true_perm, y_score_perm)
assert_almost_equal(score, current_score)
@pytest.mark.parametrize("metric_name", CLASSIFICATION_METRICS)
def test_metrics_consistent_type_error(metric_name):
# check that an understable message is raised when the type between y_true
# and y_pred mismatch
rng = np.random.RandomState(42)
y1 = np.array(["spam"] * 3 + ["eggs"] * 2, dtype=object)
y2 = rng.randint(0, 2, size=y1.size)
err_msg = "Labels in y_true and y_pred should be of the same type."
with pytest.raises(TypeError, match=err_msg):
CLASSIFICATION_METRICS[metric_name](y1, y2)
@pytest.mark.parametrize(
"metric, y_pred_threshold",
[
(average_precision_score, True),
(brier_score_loss, True),
(f1_score, False),
(partial(fbeta_score, beta=1), False),
(jaccard_score, False),
(precision_recall_curve, True),
(precision_score, False),
(recall_score, False),
(roc_curve, True),
],
)
@pytest.mark.parametrize("dtype_y_str", [str, object])
def test_metrics_pos_label_error_str(metric, y_pred_threshold, dtype_y_str):
# check that the error message if `pos_label` is not specified and the
# targets is made of strings.
rng = np.random.RandomState(42)
y1 = np.array(["spam"] * 3 + ["eggs"] * 2, dtype=dtype_y_str)
y2 = rng.randint(0, 2, size=y1.size)
if not y_pred_threshold:
y2 = np.array(["spam", "eggs"], dtype=dtype_y_str)[y2]
err_msg_pos_label_None = (
"y_true takes value in {'eggs', 'spam'} and pos_label is not "
"specified: either make y_true take value in {0, 1} or {-1, 1} or "
"pass pos_label explicit"
)
err_msg_pos_label_1 = (
r"pos_label=1 is not a valid label. It should be one of " r"\['eggs', 'spam'\]"
)
pos_label_default = signature(metric).parameters["pos_label"].default
err_msg = err_msg_pos_label_1 if pos_label_default == 1 else err_msg_pos_label_None
with pytest.raises(ValueError, match=err_msg):
metric(y1, y2)
def check_array_api_metric(
metric, array_namespace, device, dtype_name, y_true_np, y_pred_np, sample_weight
):
xp = _array_api_for_tests(array_namespace, device)
y_true_xp = xp.asarray(y_true_np, device=device)
y_pred_xp = xp.asarray(y_pred_np, device=device)
metric_np = metric(y_true_np, y_pred_np, sample_weight=sample_weight)
if sample_weight is not None:
sample_weight = xp.asarray(sample_weight, device=device)
with config_context(array_api_dispatch=True):
metric_xp = metric(y_true_xp, y_pred_xp, sample_weight=sample_weight)
assert_allclose(
_convert_to_numpy(xp.asarray(metric_xp), xp),
metric_np,
atol=_atol_for_type(dtype_name),
)
def check_array_api_binary_classification_metric(
metric, array_namespace, device, dtype_name
):
y_true_np = np.array([0, 0, 1, 1])
y_pred_np = np.array([0, 1, 0, 1])
check_array_api_metric(
metric,
array_namespace,
device,
dtype_name,
y_true_np=y_true_np,
y_pred_np=y_pred_np,
sample_weight=None,
)
sample_weight = np.array([0.0, 0.1, 2.0, 1.0], dtype=dtype_name)
check_array_api_metric(
metric,
array_namespace,
device,
dtype_name,
y_true_np=y_true_np,
y_pred_np=y_pred_np,
sample_weight=sample_weight,
)
def check_array_api_multiclass_classification_metric(
metric, array_namespace, device, dtype_name
):
y_true_np = np.array([0, 1, 2, 3])
y_pred_np = np.array([0, 1, 0, 2])
check_array_api_metric(
metric,
array_namespace,
device,
dtype_name,
y_true_np=y_true_np,
y_pred_np=y_pred_np,
sample_weight=None,
)
sample_weight = np.array([0.0, 0.1, 2.0, 1.0], dtype=dtype_name)
check_array_api_metric(
metric,
array_namespace,
device,
dtype_name,
y_true_np=y_true_np,
y_pred_np=y_pred_np,
sample_weight=sample_weight,
)
def check_array_api_regression_metric(metric, array_namespace, device, dtype_name):
y_true_np = np.array([[1, 3], [1, 2]], dtype=dtype_name)
y_pred_np = np.array([[1, 4], [1, 1]], dtype=dtype_name)
check_array_api_metric(
metric,
array_namespace,
device,
dtype_name,
y_true_np=y_true_np,
y_pred_np=y_pred_np,
sample_weight=None,
)
sample_weight = np.array([0.1, 2.0], dtype=dtype_name)
check_array_api_metric(
metric,
array_namespace,
device,
dtype_name,
y_true_np=y_true_np,
y_pred_np=y_pred_np,
sample_weight=sample_weight,
)
array_api_metric_checkers = {
accuracy_score: [
check_array_api_binary_classification_metric,
check_array_api_multiclass_classification_metric,
],
zero_one_loss: [
check_array_api_binary_classification_metric,
check_array_api_multiclass_classification_metric,
],
r2_score: [check_array_api_regression_metric],
}
def yield_metric_checker_combinations(metric_checkers=array_api_metric_checkers):
for metric, checkers in metric_checkers.items():
for checker in checkers:
yield metric, checker
@pytest.mark.parametrize(
"array_namespace, device, dtype_name", yield_namespace_device_dtype_combinations()
)
@pytest.mark.parametrize("metric, check_func", yield_metric_checker_combinations())
def test_array_api_compliance(metric, array_namespace, device, dtype_name, check_func):
check_func(metric, array_namespace, device, dtype_name)