matplolib) 3d plotting하기

3d로 플로팅합시다.

• 예전에 matlab를 쓸 때, surf로 뭔가 화려한 surface를 그려낸 기억이 나네요. 비슷하게 여기서도 할 수 있을 것 같아서 찾아보니, 너무 당연하지만 있습니다 하하하핫.
• 정리하고 보니 매우 간단하기는 하네요 하하핫

# plotting random walk by normal dist. 
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D
import numpy as np 

fig = plt.figure(figsize=(10, 5))
ax = fig.add_subplot(111, projection='3d') # Axe3D object

sample_size = 50
x = np.cumsum(np.random.normal(0, 1, sample_size))
y = np.cumsum(np.random.normal(0, 1, sample_size))
z = np.cumsum(np.random.normal(0, 1, sample_size))
ax.plot(x, y, z, alpha=0.6, marker='o')
plt.savefig('../../assets/images/markdown_img/180612_1225_3dplotting_plotting.svg')
plt.title("ax.plot")
plt.show()

# scattering 
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D
import numpy as np 

fig = plt.figure(figsize=(10, 5))
ax = fig.add_subplot(111, projection='3d') # Axe3D object

sample_size = 500
x = np.cumsum(np.random.normal(0, 5, sample_size))
y = np.cumsum(np.random.normal(0, 5, sample_size))
z = np.cumsum(np.random.normal(0, 5, sample_size))
ax.scatter(x, y, z, c = z, s= 20, alpha=0.5, cmap=plt.cm.Greens)
plt.savefig('../../assets/images/markdown_img/180612_1225_3dplotting_scattering.svg')
plt.title("ax.scatter")
plt.show()

# contour3d
x = np.linspace(-6, 6, 30)
y = np.linspace(-6, 6, 30)
x, y = np.meshgrid(x, y)
z = np.sin(np.sqrt(x**2 + y**2))

fig = plt.figure(figsize=(12, 6))
ax = plt.axes(projection='3d')
ax.contour3D(x, y, z, 20, cmap=plt.cm.rainbow)
#ax.view_init(45, 45) 방향 돌려서 보기. 
plt.savefig('../../assets/images/markdown_img/180612_1225_3dplotting_contour.svg')
plt.title("ax.contour3D")
plt.show()

wrap-up

• contour를 그릴 때는 meshgrid로 값을 넘겨주어야 함을 명심하좌

reference

• https://matplotlib.org/mpl_toolkits/mplot3d/tutorial.html