# numpy matrix operations | identity() function

`numpy.matlib.identity()` is another function for doing matrix operations in numpy. It returns a square identity matrix of given input size.

Syntax : numpy.matlib.identity(n, dtype=None)

Parameters :
n : [int] Number of rows and columns in the output matrix.
dtype : [optional] Desired output data-type.

Return : n x n matrix with its main diagonal set to one, and all other elements zero.

Code #1 :

 `# Python program explaining ` `# numpy.matlib.identity() function ` ` `  `# importing matrix library from numpy ` `import` `numpy as geek ` `import` `numpy.matlib ` ` `  `# desired 3 x 3 output square identity matrix  ` `out_mat ``=` `geek.matlib.identity(``3``)  ` `print` `(``"Output matrix : "``, out_mat)  `

Output :

```Output matrix :
[[ 1.  0.  0.]
[ 0.  1.  0.]
[ 0.  0.  1.]]
```

Code #2 :

 `# Python program explaining ` `# numpy.matlib.identity() function ` ` `  `# importing numpy and matrix library ` `import` `numpy as geek ` `import` `numpy.matlib ` ` `  `# desired 5 x 5 output square identity matrix  ` `out_mat ``=` `geek.matlib.identity(n ``=` `5``, dtype ``=` `int``)  ` `print` `(``"Output matrix : "``, out_mat)  `

Output :

```Output matrix :
[[1 0 0 0 0]
[0 1 0 0 0]
[0 0 1 0 0]
[0 0 0 1 0]
[0 0 0 0 1]]
```

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