MATLAB Function Reference |

**Syntax**

**Description**

```
Y = eye(n)
```

returns the `n`

-by-`n`

identity matrix.

```
Y = eye(m,n) or eye([m n])
```

returns an `m`

-by-`n`

matrix with `1`

's on the diagonal and `0`

's elsewhere.

```
Y = eye(size(A))
```

returns an identity matrix the same size as `A`

.

**Limitations**

The identity matrix is not defined for higher-dimensional arrays. The assignment `y = eye([2,3,4])`

results in an error.

**See Also**

expm | ezcontour |