The diagonal() function in Python is simply used to return a specified diagonal from a given 2D array.
numpy.diagonal(a, offset=0, axis1=0, axis2=1)
Note: To use
numpy.diagonal()function, firstimport numpy.
The diagonal() function takes the following parameter values:
a: This represents the array_like object from which the diagonal is taken.offset: This represents the offset to the diagonal from the main diagonal. It could take a negative or positive integer value. The default to the main diagonal is 0. This is optional.axis1: This represents the axis to be used as the first axis of the 2D sub-arrays from which the diagonals should be taken. The default value is 0.axis2: This represents the axis to be used as the second axis of the 2D sub-arrays from which the diagonals should be taken. The default value is 1.The diagonal() function returns a diagonal array.
import numpy as np# creating an arraymyarray = np.arange(9).reshape(3, 3)# implementing the diagonal() functiondiagarray = np.diagonal(myarray, 0, 0, 1)print(myarray)print(diagarray)
numpy library.myarray of 9 elements with a dimension of 3 by 3, that is 3 rows and 3 columns, using the arange() function.diag() function on the array myarray using the main diagonal k = 0, default axis1, 0, and a default axis2, 0. The result is assigned to a new variable diagarray.myarray.diagarray.