[英]Concat two arrays of different dimensions numpy
I am trying to concatenate two numpy arrays to add an extra column: array_1
is (569, 30)
and array_2
is is (569, )
我正在尝试连接两个 numpy arrays 添加一个额外的列:
array_1
is (569, 30)
and array_2
is (569, )
combined = np.concatenate((array_1, array_2), axis=1)
I thought this would work if I set axis=2
so it will concatenate vertically.我认为如果我设置
axis=2
这将起作用,因此它将垂直连接。 The end should should be a 569 x 31 array.最后应该是一个 569 x 31 的数组。
The error I get is ValueError: all the input arrays must have same number of dimensions
我得到的错误是
ValueError: all the input arrays must have same number of dimensions
Can someone help?有人可以帮忙吗?
Thx!谢谢!
You can use numpy.column_stack
:您可以使用
numpy.column_stack
:
np.column_stack((array_1, array_2))
Which converts the 1-d array to 2-d implicitly, and thus equivalent to np.concatenate((array_1, array_2[:,None]), axis=1)
as commented by @umutto. np.concatenate((array_1, array_2[:,None]), axis=1)
一维数组隐式转换为np.concatenate((array_1, array_2[:,None]), axis=1)
数组,因此相当于np.concatenate((array_1, array_2[:,None]), axis=1)
。
a = np.arange(6).reshape(2,3)
b = np.arange(2)
a
#array([[0, 1, 2],
# [3, 4, 5]])
b
#array([0, 1])
np.column_stack((a, b))
#array([[0, 1, 2, 0],
# [3, 4, 5, 1]])
要垂直堆叠它们,请尝试 np.vstack((array1,array2))
You can convert the 1-D array to 2-D array with the same number of rows using reshape function and concatenate the resulting array horizontally using numpy's append function.您可以使用 reshape function 将一维数组转换为具有相同行数的二维数组,并使用 numpy 的 append ZC1C425268E68385D1AB54Z507F 水平连接生成的数组。
Note: In numpy's append function, we have to mention axis along which we want to insert the values.注意:在 numpy 的 append function 中,我们必须提到要插入值的轴。 If axis=0, arrays are appended vertically.
如果axis=0,则垂直附加arrays。 If axis=1, arrays are appended horizontally.
如果axis=1,则水平附加arrays。 So, we can use axis=1, for current requirement
因此,我们可以使用axis = 1来满足当前需求
eg例如
a = np.arange(6).reshape(2,3)
b = np.arange(2)
a
#array([[0, 1, 2],
# [3, 4, 5]])
b
#array([0, 1])
#First step, convert this 1-D array to 2-D (Number of rows should be same as array 'a' i.e. 2)
c = b.reshape(2,1)
c
#array([[0],
[1]])
#Step 2, Using numpy's append function we can concatenate both arrays with same number of rows horizontally
requirement = np.append((a, c, axis=1))
requirement
#array([[0, 1, 2, 0],
# [3, 4, 5, 1]])
You can simply use numpy
's hstack
function.您可以简单地使用
numpy
的hstack
函数。
eg例如
import numpy as np
combined = np.hstack((array1,array2))
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