[참조]

• 공학자를 위한 Python, 조정래, 2022: 4. Matplotlib
  https://wikidocs.net/14570
• Dookie Kim, Python: From Beginning to Application,  2022
  https://www.dropbox.com/s/oa86j9ap62esmtz/Python.pdf?dl=0 

Matplotlib은 그래프를 그리는 패키지이다.

(5) 3D 그래프 
 1) line and scatter
 2) surface
 3) bar3d 
 

(5) 3D 그래프 

1) line and scatter

• Ex)
  import matplotlib.pyplot as plt
  from mpl_toolkits.mplot3d import Axes3D # 3D plot을 위해 필요
  import numpy as np

  # line plot
  fig = plt.figure()
  ax = fig.gca(projection='3d') # Axes3D 객체 생성

  theta = np.linspace(-4*np.pi,4*np.pi,100)
  z = np.linspace(-2,2,100)

  r = z**2+1
  x = r*np.sin(theta)
  y = r*np.cos(theta)

  ax.plot(x,y,z,label='parametric curve')
  ax.scatter(x,y,z)
  ax.legend()

  ax.set_xlabel('X')
  ax.set_ylabel('Y')
  ax.set_zlabel('Z')

  fig.tight_layout()
  plt.show()

  
   

2) surface

• Ex)
  import matplotlib.pyplot as plt
  from mpl_toolkits.mplot3d import Axes3D
  import numpy as np

  fig = plt.figure()
  ax = fig.gca(projection='3d') # Axes3D 객체 생성

  X=np.arange(-5,5,0.25)
  Y=np.arange(-5,5,0.25)
  X,Y = np.meshgrid(X,Y) # 격자 grid 생성
  R = np.sqrt(X**2+Y**2)
  Z = np.sin(R)

  surf = ax.plot_surface(X,Y,Z,cmap='coolwarm',lw=0,antialiased=False)
  wire = ax.plot_wireframe(X,Y,Z,color='r',lw=0.1)
  fig.colorbar(surf,shrink=0.5,aspect=5)
  fig.tight_layout()
  plt.show()

  
   

3) bar3d

• Ex)
  import matplotlib.pyplot as plt
  from mpl_toolkits.mplot3d import Axes3D
  import numpy as np

  # setup the figure and axes
  fig = plt.figure(figsize=(8, 3))
  ax1 = fig.add_subplot(121, projection='3d') # Axes3D 객체 생성
  ax2 = fig.add_subplot(122, projection='3d')

  # fake data
  _x = np.arange(4)
  _y = np.arange(5)
  _xx, _yy = np.meshgrid(_x, _y) # 격자 grid 생성
  x, y = _xx.ravel(), _yy.ravel() # 다차원 배열을 1차원 배열로 풀기

  top = x + y
  bottom = np.zeros_like(top) # top과 같은 사이즈의 0 배열 생성
  width = depth = 1

  ax1.bar3d(x, y, bottom, width, depth, top, shade=True)
  ax1.set_title('Shaded')

  ax2.bar3d(x, y, bottom, width, depth, top, shade=False)
  ax2.set_title('Not Shaded')

  plt.show()