python - append Python 3D Numpy 数组

Question

我有一些关于 3D python numpy 的问题

import numpy as np
n = 5
m = 4

Sc = np.random.rand(m,n,n)
S1 = np.zeros((1,n+2))
S2 = np.zeros((n,1))

A0 = np.r_[S1, np.c_[S2, Sc[0], S2], S1]
A1 = np.r_[S1, np.c_[S2, Sc[1], S2], S1]
#print(A)
#print(B)
A = np.array([A0,A1])
A.shape
Atmp = np.r_[S1, np.c_[S2, Sc[2], S2], S1]

A 的维度 = (2, 7, 7)

Atmp = (7,7) 的维数。

如何将 Atmp append 到 A？

Answer 1

如果可以，请不要concatenate/append/stack 数组，尤其是大数组。这非常浪费内存而且速度很慢。

赋值 A = np.empty((m, n+2, n+2)) 然后用 A[i] = np.r_[S1, np. c_[S2, Sc[i], S2], S1].或者将其矢量化并摆脱 for 循环:

A = np.zeros((m, n+2, n+2))
A[:,1:-1,1:-1] = Sc

甚至一行完成:

A = np.pad(Sc, ((0,0),(1,1),(1,1)), 'constant', constant_values = 0)