【GIS】IDW

Python三维图

image.png

#encoding=utf-8
import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D
# 3D coordination
fig = plt.figure()
ax = fig.gca(projection='3d')

#set axis length 
ax.set_xlim(70, 200)
ax.set_ylim(-90, 180)
ax.set_zlim(0, 10)
# set axis label
ax.set_zlabel('Z', fontdict={'size': 15, 'color': 'red'})
ax.set_ylabel('Y', fontdict={'size': 15, 'color': 'blue'})
ax.set_xlabel('X', fontdict={'size': 15, 'color': 'yellow'})
plt.show()

空间数据散点图

image.png

因为坐标轴没用从零点开始，所以绘制蓝色的点表示（0,0,0）坐标原点

#encoding=utf-8
import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D

fig = plt.figure()
ax = fig.gca(projection='3d')

# np.array( ) 切片 input data
data=np.array([
[129.0,    7.5,  4],
[140.0,  141.5,  8],
[108.5,   28.0,  6],
[ 88.0,  147.0,  8],
[185.5,   22.5,  6],
[195.0,  137.5,  8],
[105.5,   85.5,  8],
[157.5,   -6.5,  9],
[107.5,  -81.0,  9],
[ 77.0,    3.0,  8],
[81.0,   56.5,  8],
[162.0,   84.0,  4],
[117.5,  -38.5,  9],
[162.0,  -66.5,  9]     ])


x = data[:,0]
y = data[:,1]
z = data[:,2]

ax.scatter(x, y, z, c='r')
ax.scatter(0, 0, 0, c='b')

ax.set_xlim(70, 200)
ax.set_ylim(-90, 180)
ax.set_zlim(0, 10)
ax.set_zlabel('Z', fontdict={'size': 15, 'color': 'red'})
ax.set_ylabel('Y', fontdict={'size': 15, 'color': 'red'})
ax.set_xlabel('X', fontdict={'size': 15, 'color': 'red'})
plt.show()

---

1.https://giscourses.cfans.umn.edu/sites/giscourses.cfans.umn.edu/files/interpolation.pdf

2. https://system.umn.edu/
   一个简答的IDW插值Demo

image.png

通过三个已知点对中间点的数值进行插值估算。

image.png

#encoding=utf-8
import numpy as np
import matplotlib.pyplot as plt


z =np.array([50,30,52])
d=np.array([4,2,6])
p=1
A=sum(z*1/(d**p))
B=sum(1/(d**p))
z0=A/B
print(z0)