ArcPy 批处理之 [ 批量采样栅格属性值构建箱型图(BoxPlot)的数据准备]

将单幅栅格影像的属性值参与到箱型图中的一个Box中，考虑像元数量过多，进行1%或者0.5%采样，此处额外统计最小值、最大值、均值和中位数。

ArcPy 代码(此处为3.x 版本，与Python2.7 存在差异)：

#encoding:utf-8 

import os
import arcpy
from arcpy import env
from arcpy.sa import *
import numpy as np
import pandas as pd

arcpy.env.overwriteOutput=1
inPath = r'D:\Data\gdb.gdb'
outPath= r'D:\Data\\'
out_file = "result.xlsx"
arcpy.env.workspace = inPath
files   = arcpy.ListRasters()
num=len(files)

def calculate_percentiles(array):
    percentiles = np.nanpercentile(array, range(101))
    max_val = np.nanmax(array)
    min_val = np.nanmin(array)
    median = np.nanmedian(array)
    mean = np.nanmean(array)
    return np.concatenate(([min_val, median, max_val, mean], percentiles))

result_df = pd.DataFrame(columns=['Array', 'Min', 'Median', 'Max', 'Mean'] + [f'pct_{i}%' for i in range(101)])

for i in range(num):
    np_array = arcpy.RasterToNumPyArray(Raster(files[i]), nodata_to_value=np.nan)
    percentiles = calculate_percentiles(np_array)
    result_df.loc[i] = [files[i]] + list(percentiles)
    print(files[i]+" ok")
    
result_df.to_excel(outPath + out_file, index=False)
print("OKK") 

 

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