MATLAB Function Reference |

**Syntax**

**Description**

```
NaN
```

returns the IEEE arithmetic representation for Not-a-Number (`NaN`

). These result from operations which have undefined numerical results.

**Examples**

- Any arithmetic operation on a
`NaN`

, such as`sqrt(NaN)`

- Addition or subtraction, such as magnitude subtraction of infinities as
`(+Inf)+(-Inf)`

- Multiplication, such as
`0*Inf`

- Division, such as
`0/0`

and`Inf/Inf`

- Remainder, such as
`rem(x,y)`

where`y`

is zero or`x`

is infinity

**Remarks**

Because two `NaN`

s are not equal to each other, logical operations involving `NaN`

s always return false, except ~= (not equal). Consequently,

and the `NaN`

s in a vector are treated as different unique elements.

Use the `isnan`

function to detect `NaN`

s in an array.

**See Also**

`Inf`

, `isnan`

namelengthmax | nargchk |