Python如何画P-R曲线

#coding:utf-8

import matplotlib

import numpy as np

import matplotlib.pyplot as plt

from sklearn.metrics import precision_recall_curve

from sklearn.utils.fixes import signature

plt.figure("P-R Curve")

plt.title('Precision/Recall Curve')

plt.xlabel('Recall')

plt.ylabel('Precision')

#y_true为样本实际的类别，y_scores为样本为正例的概率

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

y_scores = np.array([0.9, 0.75, 0.86, 0.47, 0.55, 0.56, 0.74, 0.62, 0.5, 0.86, 0.8, 0.47, 0.44, 0.67, 0.43, 0.4, 0.52, 0.4, 0.35, 0.1])

precision, recall, thresholds = precision_recall_curve(y_true, y_scores)

#print(precision)

#print(recall)

#print(thresholds)

plt.plot(recall,precision)

plt.show()