Python 二维矩阵中的插值

Python 二维矩阵中的插值,python,numpy,raster,Python,Numpy,Raster,我尝试在二维数组上插值,其中数组的值在零之间,我想用接近或接近这些值的值替换这些值,我已经回顾了几个示例,但我的搜索没有成功,我尝试了以下插值代码 import numpy as np from scipy import interpolate mymin,mymax = 0,3 X = np.linspace(mymin,mymax,4) Y = np.linspace(mymin,mymax,4) x,y = np.meshgrid(X,Y) test = np.array([[

我尝试在二维数组上插值,其中数组的值在零之间,我想用接近或接近这些值的值替换这些值,我已经回顾了几个示例,但我的搜索没有成功,我尝试了以下插值代码

import numpy as np
from scipy import interpolate

mymin,mymax = 0,3

X = np.linspace(mymin,mymax,4)

Y = np.linspace(mymin,mymax,4)

x,y = np.meshgrid(X,Y)


test = np.array([[ 1.2514318 , 0,  1.25148472,  1.25151133],
  [ 1.25087456,  0,  1.25092764,  1.25095435],
  [   1.25031581,  1.25034238,  1.25036907,  0],
  [ 0,  1.24978222,  0,  1.24983587]])

f = interpolate.interp2d(x,y,test,kind='linear')

X_n = np.linspace(mymin,mymax,4)
Y_n = np.linspace(mymin,mymax,4)

test_n = f(X_n,Y_n)

print (test_n)

[[ 1.25143180e+00  2.77555756e-16  1.25148472e+00  1.25151133e+00]
[ 1.25087456e+00  2.49800181e-16  1.25092764e+00  1.25095435e+00]
[ 1.25031581e+00  1.25034238e+00  1.25036907e+00  1.38777878e-17]
[ 5.33635770e-17  1.24978222e+00 -1.11022302e-16  1.24983587e+00]]

你可以看到它是否正确工作,但是零点的位置,它变成了一个非常小的值,它与它周围的值不一致,我的插值方式是否有故障?

< P> Python不能知道你不想考虑零值。因此,您需要将其从二维阵列中删除:

import numpy as np
from scipy import interpolate

# Dummy data
d = np.array([[1.2514318 ,  0,           1.25148472,  1.25151133],
              [1.25087456,  0,           1.25092764,  1.25095435],
              [1.25031581,  1.25034238,  1.25036907,  0         ],
              [0,           1.24978222,  0,           1.24983587]])

# Get the index of the non zero values
y,x = np.where(d!=0)      

# Create your interpolation function on the non zero values
f = interpolate.interp2d(x,y,d[d!=0],kind='linear')

# Interpolate
X = np.arange(len(d))
print(f(X,X))

# OUTPUT:
#[[1.2514318  1.25145823 1.25148472 1.25151133]
# [1.25087456 1.25090106 1.25092764 1.25095435]
# [1.25031581 1.25034238 1.25036907 1.25039598]
# [0.94306808 1.24978222 1.39770265 1.24983587]]
请注意,此2D线性插值为空间域边界上的值提供了一些非常糟糕的结果。这是意料之中的,因为线性插值无法猜测给定空间域之外的值