Draw two legends in one figure using Python & Matplotlib.pyplot

In [1]:

%matplotlib inline
import matplotlib.pyplot as plt
import numpy as np

In [2]:

plt.figure(figsize=(4,3))

l1, = plt.plot([0,1],[1,0],label="l1")
l2, = plt.plot([0,1],[1.1,0],label="l2")
l3, = plt.plot([0,1],[1.2,0],label="l3")
h1 = [l1, l2, l3]
l4, = plt.plot([0,1],[0,1],"--",label="l4")
l5, = plt.plot([0,1],[0,1.1],"--",label="l5")
h2 = [l4, l5]

lab1 = [ h.get_label() for h in h1]
lab2 = [ h.get_label() for h in h2]

leg1 = plt.legend(h1,lab1, loc=1)
leg2 = plt.legend(h2,lab2, loc=4)

plt.gca().add_artist(leg1) # 最後の legend しか自動認識してくれない
plt.show()

One ylabel for two subplots using Python Matplotlib.pyplot

The result is:

This page shows how to write one label on two subplots using python and matplotlib.pyplot. By set label_coords of the ylabel, you can move the position of the ylabel.

Write text annotation on image using Python Matplotlib.pyplot

The result is:

This page shows how to write texts and put plots on the image using Python and Matplotlib.pyplot. The Figures can be exported as vector image such as pdf and svg using plt.savefig. It is impossible if you use save function of PIL; Python Image Library.