matplotlib繪圖：1.基本操作

#learn matpltlib

import matplotlib.pyplot as plt
import numpy as np

''' plotting several lines with different format styles in one command using arrays'''
def test1(): 
    t=np.arange(0,5,0.2)
    plt.plot(t,t,'r--',t,t**2,'bs',t,t**3,'g^')

'''create multiple figures by using multiple figure() calls with an increasing 
figure number. Of course, each figure can contain as many axes and subplots as 
your heart desires:    '''
def f(t):
    return np.exp(-t)*np.cos(2*np.pi*t)
    
def test2():
    t1=np.arange(0.0,5.0,0.1)
    t2=np.arange(0.0,5.0,0.02)
    plt.figure(1)
    plt.subplot(211)
    plt.plot(t1,f(t1),'bo',t2,f(t2),'k')
    plt.xlabel('x')
    plt.ylabel('y')
    plt.title('figure1-1')
    #Annotating text
    plt.annotate('local max',xy=(0,1),xytext=(1,0.6),arrowprops
                 =dict(facecolor='black',shrink=0.05),)
    plt.subplot(212)
    plt.plot(t2,np.cos(2*np.pi*t2),'r--')
    plt.xlabel('x')
    plt.ylabel('y')
    plt.title('figure1-2')
    
    plt.figure(2)
    plt.subplot(121)
    plt.plot([1,2,3],[1,2,3])
    plt.xlabel('x')
    plt.ylabel('y')
    plt.title('figure2-1')
    plt.subplot(122)
    x=np.arange(0,5,0.1)
    plt.plot(x,x**2)
    plt.xlabel('x')
    plt.ylabel('y')
    plt.title('figure2-2')

if __name__=="__main__":
    test1()
    test2()

http://matplotlib.org/users/pyplot_tutorial.html#working-with-multiple-figures-and-axes