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`

.

`eye(m, n, classname)`

or `eye([m,n],classname)`

is an m-by-n matrix with 1's of class `classname`

on the diagonal and zeros of class `classname`

elsewhere. `classname`

is a string specifying the data type of the output. `classname`

can have the following values: `'double'`

, `'single'`

, `'int8'`

, `'uint8'`

, `'int16'`

, `'uint16'`

, `'int32'`

, `'uint32'`

, `'int64'`

, or `'uint64'`

.

**Example:**

**Limitations**

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

results in an error.

**See Also**

expm1 | ezcontour |

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