title: How to change plot_confusion_matrix default figure size in sklearn.metrics package
body: <p>I tried to plot confusion matrix with Jupyter notebook using sklearn.metrics.plot_confusion_matrix package, but the default figure size is a little bit small. I have added plt.figure(figsize=(20, 20)) before plotting, but the figure size did not change with output text 'Figure size 1440x1440 with 0 Axes'. How can I change the figure size?</p>
  
  <pre><code>%matplotlib inline
  from sklearn.ensemble import GradientBoostingClassifier
  from sklearn.metrics import plot_confusion_matrix
  from matplotlib import pyplot as plt
  
  plt.figure(figsize=(20, 20))
  clf = GradientBoostingClassifier(random_state=42)
  clf.fit(X_train, y_train)
  plot_confusion_matrix(clf, X_test, y_test, cmap=plt.cm.Blues)
  plt.title('Confusion matrix')
  plt.show()
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/2d0NJ.png" rel="noreferrer">just like this image</a></p>