Drawing Contour FIG Matplotlib

Original Address

Categories --Matplotlib

• First observed effect

  

• Import Support Package

  import matplotlib.pyplot as plt
  import numpy as np
  

• Generating a defined function of the heightf(x,y)

  def f(x,y):
      # 生成高度（等高线的‘高’）的函数
      return (1 - x / 2 + x**5 + y**3) * np.exp(-x**2 -y**2)
  

• Generate test data

  n = 256
  x = np.linspace(-3, 3, n)
  y = np.linspace(-3, 3, n)
  X,Y = np.meshgrid(x, y)
  

• Drawing height color map

  # use plt.contourf to filling contours
  # X, Y and value for (X,Y) point
  plt.contourf(X, Y, f(X, Y), 30, alpha=.9, cmap=plt.get_cmap('rainbow'))
  # 30这个数字值可以理解为图中颜色跨度
  # alpha     透明度
  # cmap      pyplot下的color map，取值可参见https://matplotlib.org/examples/color/colormaps_reference.html
  

  In this case it is showing a

  

• Drawing Contour

  # use plt.contour to add contour lines
  C = plt.contour(X, Y, f(X, Y), levels=8, colors='black', alpha=.7)
  # colors    等高线的颜色
  # levels    等高线的密度（越大越密）
  # alpha     登高线的不透明度，[0,1],越大越不透明
  

• Add height contour lines marked

  plt.clabel(C, inline=True, fontsize=10)
  # inline    是否把lable嵌入在线内
  # fontzise  标注字大小
  # color     标注字颜色
  # inline_spacing : float
  

• Hidden axis scale

  # 隐藏轴上的刻度
  plt.xticks(())
  plt.yticks(())
  

• Showing

  plt.show()
  

  As shown in the first effect described in FIG.

• Explanation

  Copied in order to execute the program

• references

  The main program from Contours contour map , slight changes