python column of matrix code example
Example 1: how to address a column in a 2d array python
>>> import numpy as np
>>> A = np.array([[1,2,3,4],[5,6,7,8]])
>>> A
array([[1, 2, 3, 4],
[5, 6, 7, 8]])
>>> A[:,2] # returns the third columm
array([3, 7])
Example 2: numpy matrix in python 3
np.matrix([[1, 2], [3, 4]])
# matrix([[1, 2],
# [3, 4]])
Example 3: get column or row of matrix array numpy python
test = numpy.array([[1, 2], [3, 4], [5, 6]])
column = test[:,0]
# column == array([1, 3, 5])
row = test[1,:]
# row == array([3, 4])