# NAN
> Canonical double-precision complex floating-point `NaN`.
## Usage
```javascript
var COMPLEX128_NAN = require( '@stdlib/constants/complex128/nan' );
```
#### COMPLEX128_NAN
Canonical double-precision complex floating-point `NaN`.
```javascript
var real = require( '@stdlib/complex/float64/real' );
var imag = require( '@stdlib/complex/float64/imag' );
var re = real( COMPLEX128_NAN );
// returns NaN
var im = imag( COMPLEX128_NAN );
// returns NaN
```
## Examples
```javascript
var real = require( '@stdlib/complex/float64/real' );
var imag = require( '@stdlib/complex/float64/imag' );
var Complex128Array = require( '@stdlib/array/complex128' );
var COMPLEX128_NAN = require( '@stdlib/constants/complex128/nan' );
var x = new Complex128Array( [ 1.0, 2.0, 3.0, 4.0 ] );
// returns
var v = x.get( 0 );
// returns
var re = real( v );
// returns 1.0
var im = imag( v );
// returns 2.0
x.fill( COMPLEX128_NAN );
v = x.get( 0 );
// returns
re = real( v );
// returns NaN
im = imag( v );
// returns NaN
```
[@stdlib/constants/complex64/nan]: https://github.com/stdlib-js/constants/tree/main/complex64/nan