如何从多维NumPy数组中选择x%的值并设置阈值？

import numpy as np

arr = np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]])

threshold = np.percentile(arr, x)

selected_values = arr[arr > threshold]

arr[arr > threshold] = new_value

import numpy as np

arr = np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]])

x = 50  # 选择前50%的值
threshold = np.percentile(arr, x)
selected_values = arr[arr > threshold]

new_value = 10  # 设置阈值后的新值
arr[arr > threshold] = new_value

print("原始数组：")
print(arr)
print("选择的值：")
print(selected_values)
print("设置阈值后的数组：")
print(arr)