Files
mt/Deep-SAD-PyTorch/src/datasets/preprocessing.py
2024-07-03 17:39:32 +02:00

122 lines
4.2 KiB
Python

import torch
import numpy as np
import logging
def create_semisupervised_setting(
labels,
normal_classes,
outlier_classes,
known_outlier_classes,
ratio_known_normal,
ratio_known_outlier,
ratio_pollution,
):
"""
Create a semi-supervised data setting.
:param labels: np.array with labels of all dataset samples
:param normal_classes: tuple with normal class labels
:param outlier_classes: tuple with anomaly class labels
:param known_outlier_classes: tuple with known (labeled) anomaly class labels
:param ratio_known_normal: the desired ratio of known (labeled) normal samples
:param ratio_known_outlier: the desired ratio of known (labeled) anomalous samples
:param ratio_pollution: the desired pollution ratio of the unlabeled data with unknown (unlabeled) anomalies.
:return: tuple with list of sample indices, list of original labels, and list of semi-supervised labels
"""
idx_normal = np.argwhere(np.isin(labels, normal_classes)).flatten()
idx_outlier = np.argwhere(np.isin(labels, outlier_classes)).flatten()
idx_known_outlier_candidates = np.argwhere(
np.isin(labels, known_outlier_classes)
).flatten()
n_normal = len(idx_normal)
# Solve system of linear equations to obtain respective number of samples
a = np.array(
[
[1, 1, 0, 0],
[
(1 - ratio_known_normal),
-ratio_known_normal,
-ratio_known_normal,
-ratio_known_normal,
],
[
-ratio_known_outlier,
-ratio_known_outlier,
-ratio_known_outlier,
(1 - ratio_known_outlier),
],
[0, -ratio_pollution, (1 - ratio_pollution), 0],
]
)
b = np.array([n_normal, 0, 0, 0])
x = np.linalg.solve(a, b)
# Get number of samples
n_known_normal = int(x[0])
n_unlabeled_normal = int(x[1])
n_unlabeled_outlier = int(x[2])
n_known_outlier = int(x[3])
if (
sum((n_known_normal, n_unlabeled_normal, n_unlabeled_outlier, n_known_outlier))
> labels.shape[0]
):
logger = logging.getLogger()
logger.error(
"Given ratios for the semi-supervised setting are not possible due to data restraints. Please change the ratios or provide more/different data."
)
# Sample indices
perm_normal = np.random.permutation(n_normal)
perm_outlier = np.random.permutation(len(idx_outlier))
perm_known_outlier = np.random.permutation(len(idx_known_outlier_candidates))
idx_known_normal = idx_normal[perm_normal[:n_known_normal]].tolist()
idx_unlabeled_normal = idx_normal[
perm_normal[n_known_normal : n_known_normal + n_unlabeled_normal]
].tolist()
idx_unlabeled_outlier = idx_outlier[perm_outlier[:n_unlabeled_outlier]].tolist()
idx_known_outlier = idx_known_outlier_candidates[
perm_known_outlier[:n_known_outlier]
].tolist()
# Get original class labels
labels_known_normal = labels[idx_known_normal].tolist()
labels_unlabeled_normal = labels[idx_unlabeled_normal].tolist()
labels_unlabeled_outlier = labels[idx_unlabeled_outlier].tolist()
labels_known_outlier = labels[idx_known_outlier].tolist()
# Get semi-supervised setting labels
semi_labels_known_normal = np.ones(n_known_normal).astype(np.int32).tolist()
semi_labels_unlabeled_normal = (
np.zeros(n_unlabeled_normal).astype(np.int32).tolist()
)
semi_labels_unlabeled_outlier = (
np.zeros(n_unlabeled_outlier).astype(np.int32).tolist()
)
semi_labels_known_outlier = (-np.ones(n_known_outlier).astype(np.int32)).tolist()
# Create final lists
list_idx = (
idx_known_normal
+ idx_unlabeled_normal
+ idx_unlabeled_outlier
+ idx_known_outlier
)
list_labels = (
labels_known_normal
+ labels_unlabeled_normal
+ labels_unlabeled_outlier
+ labels_known_outlier
)
list_semi_labels = (
semi_labels_known_normal
+ semi_labels_unlabeled_normal
+ semi_labels_unlabeled_outlier
+ semi_labels_known_outlier
)
return list_idx, list_labels, list_semi_labels