python如何计算auc

python -V

Python 2.7.3

python -c 'import scipy; print scipy.version.version'

0.9.0

python -c "import numpy; print numpy.version.version"

1.10.2

pip install - U scikit - learn

import numpy as np

from sklearn.metrics import roc_auc_score

y_true = np.array([0, 0, 1, 1])

y_scores = np.array([0.1, 0.4, 0.35, 0.8])

roc_auc_score(y_true, y_scores)

0.75

import numpy as np

from sklearn import metrics

y = np.array([1, 1, 2, 2])   #实际值

scores = np.array([0.1, 0.4, 0.35, 0.8])  #预测值

fpr, tpr, thresholds = metrics.roc_curve(y, scores, pos_label=2)  #pos_label=2，表示值为2的实际值为正样本

print fpr

print tpr

print thresholds

array([ 0. ,  0.5,  0.5,  1. ])

array([ 0.5,  0.5,  1. ,  1. ])

array([ 0.8 , 0.4 , 0.35, 0.1 ])