莫烦python教程学习笔记——learn_curve曲线用于过拟合问题

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"""
Please note, this code is only for python 3+. If you are using python 2+, please modify the code accordingly.
"""
from __future__ import print_function
from sklearn.learning_curve import  learning_curve
from sklearn.datasets import load_digits
from sklearn.svm import SVC
import matplotlib.pyplot as plt
import numpy as np

digits = load_digits()
X = digits.data
y = digits.target
train_sizes, train_loss, test_loss= learning_curve(
        SVC(gamma=0.01), X, y, cv=10, scoring='mean_squared_error',
        train_sizes=[0.1, 0.25, 0.5, 0.75, 1])
train_loss_mean = -np.mean(train_loss, axis=1)
test_loss_mean = -np.mean(test_loss, axis=1)

plt.plot(train_sizes, train_loss_mean, 'o-', color="r",
             label="Training")
plt.plot(train_sizes, test_loss_mean, 'o-', color="g",
             label="Cross-validation")

plt.xlabel("Training examples")
plt.ylabel("Loss")
plt.legend(loc="best")
plt.show()