python 实现矩阵填充0的例子

Z时代
2024-01-10
分类：综合

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)