# NumPy - matlib.eye() function

The NumPy matlib.eye() function returns a matrix with ones on the diagonal and zeros elsewhere.

### Syntax

```numpy.matlib.eye(n, M=None, k=0, dtype='float', order='C')
```

### Parameters

 `n` `Required. `Specify number of rows in the matrix. `M` `Optional. `Specify number of columns in the matrix. Default is n. `k` `Optional. `Specify index of the diagonal. 0 refers to the main diagonal, a positive value refers to an upper diagonal, and a negative value to a lower diagonal. `dtype` `Optional. `Specify the desired data-type for the matrix. Default: float `order` `Optional. `Specify whether to store the result. Two possible values are: C (C-style) and F (Fortran-style). Default: 'C'

### Return Value

Returns a matrix with ones on the diagonal and zeros elsewhere.

### Example:

In the example below, matlib.eye() function is used to create matrix using different available parameters.

```import numpy as np
import numpy.matlib

#using default parameters
mat1 = np.matlib.eye(n=3)
print("mat1 is:\n", mat1)

#using positive k
mat2 = np.matlib.eye(n=3, M=4, k=1)
print("\nmat2 is:\n", mat2)

#using negative k with int data type
mat3 = np.matlib.eye(n=3, M=4, k=-1, dtype=int)
print("\nmat3 is:\n", mat3)
```

The output of the above code will be:

```mat1 is:
[[1. 0. 0.]
[0. 1. 0.]
[0. 0. 1.]]

mat2 is:
[[0. 1. 0. 0.]
[0. 0. 1. 0.]
[0. 0. 0. 1.]]

mat3 is:
[[0 0 0 0]
[1 0 0 0]
[0 1 0 0]]
```

❮ NumPy - Functions

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