text: #! -*- coding:utf-8 -*-
  import math
  import numpy as np
  import matplotlib.pyplot as plt
  
  scan = np.loadtxt('laserscan.dat')
  angle = np.linspace(-math.pi/2,math.pi/2,np.shape(scan)[0],endpoint='true')
  
  ax = plt.subplot(111,projection='polar')
  ax.plot(angle,scan,color='r')
  ax.grid(True)
  plt.show()