时间:2021-08-28 09:28:06 | 栏目:Python代码 | 点击:次
需求:
原矩阵
[[1 2 3] [4 5 6] [7 8 9]]
在原矩阵元素之间填充元素 0,得到
[[1. 0. 2. 0. 3.] [0. 0. 0. 0. 0.] [4. 0. 5. 0. 6.] [0. 0. 0. 0. 0.] [7. 0. 8. 0. 9.]]
思路:
先求出扩充矩阵的维度,再按照每一行每一列遍历,根据元素的索引规律依次赋值,最终实现新的扩充矩阵。这个思路实现如下:
import numpy as np def PadMat(Ndim, Mat): Brow = Bcol = 2*Ndim-1 B = np.zeros([Brow, Bcol]) for row in range(Brow): if row%2 == 0: for col in range(Bcol): if col%2 == 0: pos_c = int(col/2) pos_r = int(row/2) # print(row, col) B[row, col] = Mat[pos_r, pos_c] else: B[row, col] = 0 return B # A = np.arange(9) + 1 # A = A.reshape([3, 3]) A = np.arange(16) + 1 A = A.reshape([4, 4]) # print(A.shape[0]) N = Arow = Acol = A.shape[0] NewMat = PadMat(Ndim=N, Mat=A) print(A) print(NewMat)
总结:
这个思路很直接,但是循环套循环是一个很笨的办法,而且遍历也很慢。不知道网友有什么好的思路吗?