Python programming adds a column method example to the numpy matrix

  • 2020-06-15 09:21:38
  • OfStack

So first of all we have 1 data that is an numpy matrix for mn and now we want to be able to add 1 column to it to make it an m matrix


import numpy as np
a = np.array([[1,2,3],[4,5,6],[7,8,9]])
b = np.ones(3)
c = np.array([[1,2,3,1],[4,5,6,1],[7,8,9,1]])
PRint(a)
print(b)
print(c)

[[1 2 3]
 [4 5 6]
 [7 8 9]]
[ 1. 1. 1.]
[[1 2 3 1]
 [4 5 6 1]
 [7 8 9 1]]

So what we're going to do is we're going to combine a, b into c

Method 1

Add rows and columns with np.c_ [] and np.r_ [], respectively


np.c_[a,b]

array([[ 1., 2., 3., 1.],
    [ 4., 5., 6., 1.],
    [ 7., 8., 9., 1.]])

np.c_[a,a]

array([[1, 2, 3, 1, 2, 3],
    [4, 5, 6, 4, 5, 6],
    [7, 8, 9, 7, 8, 9]])

np.c_[b,a]

array([[ 1., 1., 2., 3.],
    [ 1., 4., 5., 6.],
    [ 1., 7., 8., 9.]])

Method 2

Using np insert


np.insert(a, 0, values=b, axis=1)

array([[1, 1, 2, 3],
    [1, 4, 5, 6],
    [1, 7, 8, 9]])

np.insert(a, 3, values=b, axis=1)

array([[1, 2, 3, 1],
    [4, 5, 6, 1],
    [7, 8, 9, 1]])

Methods 3

Use 'column_stack'


np.column_stack((a,b))

array([[ 1., 2., 3., 1.],
    [ 4., 5., 6., 1.],
    [ 7., 8., 9., 1.]])

conclusion

That's all for this article's example of how to program Python to add 1 column to an numpy matrix. Interested friends can continue to refer to other relevant topics in this site, if there is any deficiency, welcome to leave a message!


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