偏相关系数计算

# -*- coding: utf-8 -*-
"""
Created on Mon Dec 20 16:53:39 2021
modified: https://gist.github.com/fabianp/9396204419c7b638d38f
@author: pan
"""

import numpy as np
from numpy.linalg import inv
from osgeo import gdal, gdal_array
import os, time,glob
from sklearn import linear_model
from sklearn import preprocessing
from matplotlib import pyplot as plt

def partial_corr(C):
    """
    Returns the sample linear partial correlation coefficients between pairs of variables in C, controlling 
    for the remaining variables in C.
    Parameters
    ----------
    C : array-like, shape (n, p)
        Array with the different variables. Each column of C is taken as a variable
    Returns
    -------
    P_corr : array-like, shape (p, p)
        P_corr[i, j] contains the partial correlation of C[:, i] and C[:, j] controlling
        for the remaining variables in C.
    """
    
    C = np.asarray(C)
    p = C.shape[1]
    P_corr = np.zeros((p, p)) # sample linear partial correlation coefficients
    
    corr = np.corrcoef(C,rowvar=False) # Pearson product-moment correlation coefficients.
    corr_inv = inv(corr) # the (multiplicative) inverse of a matrix.
    
    for i in range(p):
        P_corr[i, i] = 1
        for j in range(i+1, p):
            pcorr_ij = -corr_inv[i,j]/(np.sqrt(corr_inv[i,i]*corr_inv[j,j]))
            P_corr[i,j]=pcorr_ij
            P_corr[j,i]=pcorr_ij
        
    return P_corr

import numpy as np
import struct

# 生成一个数组
# 注意这里根据要求设置数据类型.astype(np.uint16)
# 不同的数据类型占用的字节数以及存储的数值范围不同，比如float32需要4字节存储
# 这一步数据类型的正确设置，与下一步从中正确读取数组密切相关
data = np.arange(10000).reshape(100,100).astype(np.uint16)
# 以二进制写模式打开一个新文件
# 关于python文件操作，可以参考：
#    https://www.runoob.com/python/file-methods.html
f = open('data/2001.raw','wb')
# 将数组写入文件
f.write(data)
# 关闭文件
f.close()

import numpy as np
import struct
# 以二进制读模式打开数据文件
f = open('data/2001.raw','rb')
# 读取数据为字符串
data = f.read()
# 关闭文件
f.close()
# 获取字符串长度
d_len = len(data)
# 根据数据头文件，设置行、列（、波段数）
row = 2090
col = 4950
band = 12
# 使用struct将data转换为uint16 tuple数组
# 对于uint16(unsigned short)类型，一般占用2字节，因此数组长度应为d_len/2, 标识为H
# 滚与其他格式，请参考：
#    https://www.cnblogs.com/gala/archive/2011/09/22/2184801.html
#    https://blog.csdn.net/weixin_41912543/article/details/108072869
data1 = struct.unpack('{}H'.format(int(d_len/4)),data)
data1 = np.array(list(data1)).reshape(band,row,col).astype(np.float32)