text: # -*- coding: utf-8 -*-
  """
  Created on Mon Oct 12 10:21:30 2020
  
  @author: lenovouser
  """
  
  from sklearn.learning_curve import  validation_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
  param_range = np.logspace(-6, -2.3, 5)
  train_loss, test_loss = validation_curve(
          SVC(), X, y, param_name='gamma', param_range=param_range, cv=10,
          scoring='mean_squared_error')
  train_loss_mean = -np.mean(train_loss, axis=1)
  test_loss_mean = -np.mean(test_loss, axis=1)
  
  plt.plot(param_range, train_loss_mean, 'o-', color="r",
               label="Training")
  plt.plot(param_range, test_loss_mean, 'o-', color="g",
               label="Cross-validation")
  
  plt.xlabel("gamma")
  plt.ylabel("Loss")
  plt.legend(loc="best")
  plt.show()