Files
2026-07-13 13:35:51 +08:00

115 lines
3.2 KiB
Python

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
This file re-uses implementation from https://github.com/yl-1993/learn-to-cluster
"""
from __future__ import division
import numpy as np
from sklearn.metrics import precision_score, recall_score
from sklearn.metrics.cluster import (
contingency_matrix,
normalized_mutual_info_score,
)
__all__ = ["pairwise", "bcubed", "nmi", "precision", "recall", "accuracy"]
def _check(gt_labels, pred_labels):
if gt_labels.ndim != 1:
raise ValueError(
"gt_labels must be 1D: shape is %r" % (gt_labels.shape,)
)
if pred_labels.ndim != 1:
raise ValueError(
"pred_labels must be 1D: shape is %r" % (pred_labels.shape,)
)
if gt_labels.shape != pred_labels.shape:
raise ValueError(
"gt_labels and pred_labels must have same size, got %d and %d"
% (gt_labels.shape[0], pred_labels.shape[0])
)
return gt_labels, pred_labels
def _get_lb2idxs(labels):
lb2idxs = {}
for idx, lb in enumerate(labels):
if lb not in lb2idxs:
lb2idxs[lb] = []
lb2idxs[lb].append(idx)
return lb2idxs
def _compute_fscore(pre, rec):
return 2.0 * pre * rec / (pre + rec)
def fowlkes_mallows_score(gt_labels, pred_labels, sparse=True):
"""The original function is from `sklearn.metrics.fowlkes_mallows_score`.
We output the pairwise precision, pairwise recall and F-measure,
instead of calculating the geometry mean of precision and recall.
"""
(n_samples,) = gt_labels.shape
c = contingency_matrix(gt_labels, pred_labels, sparse=sparse)
tk = np.dot(c.data, c.data) - n_samples
pk = np.sum(np.asarray(c.sum(axis=0)).ravel() ** 2) - n_samples
qk = np.sum(np.asarray(c.sum(axis=1)).ravel() ** 2) - n_samples
avg_pre = tk / pk
avg_rec = tk / qk
fscore = _compute_fscore(avg_pre, avg_rec)
return avg_pre, avg_rec, fscore
def pairwise(gt_labels, pred_labels, sparse=True):
_check(gt_labels, pred_labels)
return fowlkes_mallows_score(gt_labels, pred_labels, sparse)
def bcubed(gt_labels, pred_labels):
_check(gt_labels, pred_labels)
gt_lb2idxs = _get_lb2idxs(gt_labels)
pred_lb2idxs = _get_lb2idxs(pred_labels)
num_lbs = len(gt_lb2idxs)
pre = np.zeros(num_lbs)
rec = np.zeros(num_lbs)
gt_num = np.zeros(num_lbs)
for i, gt_idxs in enumerate(gt_lb2idxs.values()):
all_pred_lbs = np.unique(pred_labels[gt_idxs])
gt_num[i] = len(gt_idxs)
for pred_lb in all_pred_lbs:
pred_idxs = pred_lb2idxs[pred_lb]
n = 1.0 * np.intersect1d(gt_idxs, pred_idxs).size
pre[i] += n**2 / len(pred_idxs)
rec[i] += n**2 / gt_num[i]
gt_num = gt_num.sum()
avg_pre = pre.sum() / gt_num
avg_rec = rec.sum() / gt_num
fscore = _compute_fscore(avg_pre, avg_rec)
return avg_pre, avg_rec, fscore
def nmi(gt_labels, pred_labels):
return normalized_mutual_info_score(pred_labels, gt_labels)
def precision(gt_labels, pred_labels):
return precision_score(gt_labels, pred_labels)
def recall(gt_labels, pred_labels):
return recall_score(gt_labels, pred_labels)
def accuracy(gt_labels, pred_labels):
return np.mean(gt_labels == pred_labels)