matplotlib绘图：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()