python - 使用自己的内容将 numpy 数组扩展到特定范围

Question

将具有自己的值的数组扩展到特定大小的最有效方法是什么？

import numpy as np

# For this example, lets use an array with 4 items
data = np.array([[0,1,2],[3,4,5],[6,7,8],[9,10,11]]) # 4 items

# I want to extend it to 10 items, here's the expected result would be:
data = np.array([[ 0,  1,  2],
                 [ 3,  4,  5],
                 [ 6,  7,  8],
                 [ 9, 10, 11],
                 [ 0,  1,  2],
                 [ 3,  4,  5],
                 [ 6,  7,  8],
                 [ 9, 10, 11],
                 [ 0,  1,  2],
                 [ 3,  4,  5]])

Answer 1

您可以连接数组:

def extend_array(arr, length):
    factor, fraction = divmod(length, len(arr))
    return np.concatenate([arr] * factor + [arr[:fraction]])

>>> extend_array(data, 10)

array([[ 0,  1,  2],
       [ 3,  4,  5],
       [ 6,  7,  8],
       [ 9, 10, 11],
       [ 0,  1,  2],
       [ 3,  4,  5],
       [ 6,  7,  8],
       [ 9, 10, 11],
       [ 0,  1,  2],
       [ 3,  4,  5]])