Matplotlib-巧妙绘制背景图下散点图



import matplotlib
import matplotlib.pyplot as plt
import numpy as np
from  numpy import *
def plot_image():
    datList=[]
    for line in open("d:\\learning\\places.txt").readlines():   
        lineArr=line.split('\t')
        datList.append([float(lineArr[4]),float(lineArr[3])])
    datMat=mat(datList)
#------------------------------------------------------------------------------------------------------
    fig=plt.figure()
    rect=[0.1,0.1,0.8,0.8]
    scatterMarkers=['s','o','^','8','p','d','v','h','>','<']
    axprops=dict(xticks=[],yticks=[])
    ax0=fig.add_axes(rect,label='ax0',**axprops)
   
    imgP=plt.imread('d:\\learning\\Portland.png')
    ax0.imshow(imgP)   #背景图片
    ax1=fig.add_axes(rect,label='ax1',frameon=False)
    markerStyle=scatterMarkers[random.randint(1,6)%len(scatterMarkers)]
    ax1.scatter(datMat[:,0].flatten().A[0],datMat[:,1].flatten().A[0],marker='+',s=150,c='b')
    plt.show()
plot_image()

最后的效果是：