Numpy identity function – Python NumPy identity() Function

NumPy identity() Function:

Numpy identity function: The identity array is returned by the NumPy identity() function. The identity array is a square array with the major diagonal filled with ones.

Syntax:

numpy.identity(n, dtype=None)

Parameters

n: This is required. It represents the number of rows (and columns) in n x n output.

dtype: This is optional. It is the data type of the output. Float is the default value.

Return Value:

An n x n array with one as the main diagonal and all other entries set to 0 is returned.

NumPy identity() Function in Python

Example

Approach:

  • Import numpy module using the import keyword.
  • Pass some random number(n) as an argument to the identity() function to create an n x n array with the main diagonal set to 1 and all other entries set to 0 and store it in a variable.
  • Print the above obtained first array.
  • Pass some random number(n), datatype as int as an argument to the identity() function to create an n x n array with the main diagonal set to 1 and all other entries set to 0 (integer format) and store it in another variable.
  • Print the above obtained second array.
  • The Exit of the Program.

Below is the implementation:

# Import numpy module using the import keyword
import numpy as np
# Pass some random number(n) as an argument to the identity() function to
# create an n x n array with the main diagonal set to 1 and all other entries set to 0
# and store it in a variable.
gvn_arry1 = np.identity(3)
# Print the above obtained first array.
print("The above obtained first array = \n", gvn_arry1)

# Pass some random number(n), datatype as int as an argument to the identity() function to
# create an n x n array with the main diagonal set to 1 and all other entries set to 0
# (integer format)and store it in another variable.
gvn_arry2 = np.identity(4, dtype=int)
# Print the above obtained second array.
print("The above obtained second array = \n", gvn_arry2)

Output:

The above obtained first array = 
[[1. 0. 0.]
 [0. 1. 0.]
 [0. 0. 1.]]
The above obtained second array = 
[[1 0 0 0]
 [0 1 0 0]
 [0 0 1 0]
 [0 0 0 1]]

Example2

Here we give the datatype as the float.

# Import numpy module using the import keyword
import numpy as np
# Pass some random number(n) as an argument to the identity() function to
# create an n x n array with the main diagonal set to 1 and all other entries set to 0
# and store it in a variable.
gvn_arry1 = np.identity(3)
# Print the above obtained first array.
print("The above obtained first array = \n", gvn_arry1)

# Pass some random number(n), datatype as float as an argument to the identity() function to
# create an n x n array with the main diagonal set to 1 and all other entries set to 0
# (floating format)and store it in another variable.
gvn_arry2 = np.identity(4, dtype=float)
# Print the above obtained second array.
print("The above obtained second array = \n", gvn_arry2)

Output:

The above obtained first array = 
[[1. 0. 0.]
 [0. 1. 0.]
 [0. 0. 1.]]
The above obtained second array = 
[[1. 0. 0. 0.]
 [0. 1. 0. 0.]
 [0. 0. 1. 0.]
 [0. 0. 0. 1.]]