matplotlib 详解3 面向对象

1. 面向对象

importmatplotlib.pyplot as plt

importnumpy as np

x=np.arange(0,10,1)

y=np.random.randn(len(x))

fig=plt.figure()

ax=fig.add_subplot(111)

l,=plt.plot(x,y)

t =ax.set_title('object oriented')

plt.show()

Lesson 11 在同一个画布上做多张图

importnumpy as np

x = np.arange(1,100)

fig = plt.figure()

ax1=fig.add_subplot(221)

ax1.plot(x,x)

ax2=fig.add_subplot(222)

ax2.plot(x,-x)

ax3=fig.add_subplot(223)

ax3.plot(x,x*x)

ax4=fig.add_subplot(224)

ax4.plot(x,np.log(x))

plt.show()

x=np.arange(1,100)

plt.subplot(221)

plt.plot(x,x)

plt.subplot(222)

plt.plot(x,x*x)

plt.subplot(223)

plt.plot(x,-x)

plt.subplot(224)

plt.plot(x,np.log(x))

plt.show()

lesson 12同时产生两张图

import matplotlib.pyplot as plt

fig1 = plt.figure()

ax1= fig1.add_subplot(111)

ax1.plot([1,2,3],[3,2,1])

 

fig2 = plt.figure()

ax2= fig2.add_subplot(111)

ax2.plot([1,2,3],[1,2,3])

 

plt.show()

lesson 13 网格

plt.grid(color=’r’, linestyle =’--’, linewidth= ‘2’)

 

lesson 14 图例

plt.plot(x,y, label =’xxxx’)

plt.legend(loc=0)  #位置

plt.legend(ncol=3) #几列

plt.legend([‘normal’,’fast’,’faster’])

 

lesson 15 坐标轴的调整

原来plt.axis()

(-10.0,10.0,0.0,100)

修改

plt.axis([-5,5,20,60])

修改：plt.xlim([0,60])

plt.xlim(xmin=-5)

lesson 16 修改坐标轴

x = np.arange(1,11,1)

plt.plot(x,x)

ax = plt.gca()

ax.locator_params(‘y’,nbins=5)

plt.show()

 

lesson 16 修改日期的坐标轴

importmatplotlib.pyplot as plt

importnumpy as np

importdatetime

importmatplotlib as mpl

fig = plt.figure()

start = datetime.datetime(2015,1,1)

stop =  datetime.datetime(2016,1,1)

delta = datetime.timedelta(days=1)

dates = mpl.dates.drange(start, stop,delta)

y= np.random.rand(len(dates))

ax = plt.gca()

ax.plot_date(dates,y,linestyle='-',marker='')

date_format = mpl.dates.DateFormatter("%Y-%m-%d")

ax.xaxis.set_major_formatter(date_format)

fig.autofmt_xdate()

plt.show()