去掉对称矩阵的上三角部分或下三角部分

import numpy as np

def remove_upper_triangular(matrix):
    n = matrix.shape[0]
    lower_triangular_matrix = np.zeros((n, n))
    for i in range(n):
        for j in range(i + 1):
            lower_triangular_matrix[i, j] = matrix[i, j]
    return lower_triangular_matrix

def remove_lower_triangular(matrix):
    n = matrix.shape[0]
    upper_triangular_matrix = np.zeros((n, n))
    for i in range(n):
        for j in range(i, n):
            upper_triangular_matrix[i, j] = matrix[i, j]
    return upper_triangular_matrix

# 示例对称矩阵
A = np.array([
    [1, 2, 3],
    [2, 4, 5],
    [3, 5, 6]
])

# 去掉上三角部分
lower_triangular_A = remove_upper_triangular(A)
print("去掉上三角部分后的矩阵:")
print(lower_triangular_A)

# 去掉下三角部分
upper_triangular_A = remove_lower_triangular(A)
print("去掉下三角部分后的矩阵:")
print(upper_triangular_A)