Python 用 numpy 随机抽样选择矩阵的多行或多列

numpy提供了多种随机选取的方法，这里放三种方法，效果相同。

以从一个矩阵中随机抽取n行为例，写了三个函数，粗鄙代码，见笑

import numpy as np

#=================================================================================
def rand_row1(array,dim_needed):  #array为需要采样的矩阵，dim_needed为想要抽取的行数
    row_total = array.shape[0]
    row_sequence = np.arange(row_total)
    np.random.shuffle(row_sequence)
    return array[row_sequence[0:dim_needed],:]

#=================================================================================
def rand_row2(array,dim_needed):  #array为需要采样的矩阵，dim_needed为想要抽取的行数
    row_total = array.shape[0]
    row_sequence = np.random.permutation(row_total)
    return array[row_sequence[0:dim_needed],:]

#=================================================================================
def rand_row3(array,dim_needed):  #array为需要采样的矩阵，dim_needed为想要抽取的行数
    row_total = array.shape[0]
    row_sequence= np.random.choice(row_total,dim_needed,replace=False, p=None)
    return array[row_sequence,:]
#=================================================================================


#=============================测试
test_data = np.array([0, 0])
for i in range(100):
    test_data = np.vstack((test_data, [i+1, i+1]))
# print(test_data)
batch = rand_row1(test_data,20)
# batch = rand_row2(test_data,20)
# batch = rand_row3(test_data,20)
print(batch.shape,batch)

随机抽取n列与之类似，同志，共勉！