Question

我想“加入”两个相同形状的二维numpy数组来创建一个维度numpy数组。我可以使用循环轻松完成此操作，但我正在寻找更快的方法。这是玩具的例子。两个numpy数组是：

data1 = np.array([[1,2,3,4,5],[6,7,8,9,10],[11,12,13,14,15]])
data2 = np.array([[1,2,3,4,5],[6,7,8,9,10],[11,12,13,14,15]])*100

data1

> array([[ 1,  2,  3,  4,  5],
         [ 6,  7,  8,  9, 10],
         [11, 12, 13, 14, 15]])

data2

> array([[ 100,  200,  300,  400,  500],
         [ 600,  700,  800,  900, 1000],
         [1100, 1200, 1300, 1400, 1500]])

两者都有形状（3,5）。我想创建（3,5,2）形状numpy数组。那就是：

data3 = []
for irow in range(data1.shape[0]):
    data3_temp = []
    for icol in range(data1.shape[1]):
        data3_temp.append([data1[irow,icol],
                           data2[irow,icol]])
    data3.append(data3_temp)
data3 = np.array(data3)

data3.shape
> (3, 5, 2)

data3

>array([[[   1,  100],
    [   2,  200],
    [   3,  300],
    [   4,  400],
    [   5,  500]],

   [[   6,  600],
    [   7,  700],
    [   8,  800],
    [   9,  900],
    [  10, 1000]],

   [[  11, 1100],
    [  12, 1200],
    [  13, 1300],
    [  14, 1400],
    [  15, 1500]]])

请告诉我。

Answer 1

使用numpy.dstack按顺序深度（沿第三轴）堆叠数组：https://docs.scipy.org/doc/numpy-1.10.1/reference/generated/numpy.dstack.html

import numpy as np

data1 = np.array([[1,2,3,4,5],[6,7,8,9,10],[11,12,13,14,15]])
data2 = np.array([[1,2,3,4,5],[6,7,8,9,10],[11,12,13,14,15]])*100

print np.dstack((data1,data2))

输出：

[[[   1  100]
  [   2  200]
  [   3  300]
  [   4  400]
  [   5  500]]

 [[   6  600]
  [   7  700]
  [   8  800]
  [   9  900]
  [  10 1000]]

 [[  11 1100]
  [  12 1200]
  [  13 1300]
  [  14 1400]
  [  15 1500]]]

Answer 2

一种方法：

data3= np.zeros([ data1.shape[0],data1.shape[1], 2])

data3[:,:,0],data3[:,:,1] = data1,data2

print data3.shape
print data3

结果

(3L, 5L, 2L)

>array([[[   1,  100],
    [   2,  200],
    [   3,  300],
    [   4,  400],
    [   5,  500]],

   [[   6,  600],
    [   7,  700],
    [   8,  800],
    [   9,  900],
    [  10, 1000]],

   [[  11, 1100],
    [  12, 1200],
    [  13, 1300],
    [  14, 1400],
    [  15, 1500]]])

Answer 3

或者您可以使用r_连接符：

np.r_['2,3,0', data1, data2]
# array([[[   1,  100],
          [   2,  200],
          [   3,  300],
          [   4,  400],
          [   5,  500]],

         [[   6,  600],
          [   7,  700],
          [   8,  800],
          [   9,  900],
          [  10, 1000]],

         [[  11, 1100],
          [  12, 1200],
          [  13, 1300],
          [  14, 1400],
          [  15, 1500]]])

python：连接两个2维numpy数组来创建3维数组

3 个答案: