# Dirac Delta
> Evaluate the [Dirac delta function][dirac-delta-function].
The [Dirac delta function][dirac-delta-function] may be loosely defined as
and is constrained to satisfy the identity
Note that the [Dirac delta function][dirac-delta-function] is **not** a function in the traditional sense, as any real-valued function which is zero everywhere except at a single point, must have an integral equal to `0`.
## Usage
```javascript
var diracDelta = require( '@stdlib/math/base/special/dirac-delta' );
```
#### diracDelta( x )
Evaluates the [Dirac delta function][dirac-delta-function].
```javascript
var v = diracDelta( 0.0 );
// returns Infinity
v = diracDelta( 3.14 );
// returns 0.0
v = diracDelta( NaN );
// returns NaN
```
## Examples
```javascript
var linspace = require( '@stdlib/array/linspace' );
var diracDelta = require( '@stdlib/math/base/special/dirac-delta' );
var x = linspace( -1.0, 1.0, 101 );
var i;
for ( i = 0; i < x.length; i++ ) {
console.log( 'dirac(%d) = %d', x[ i ], diracDelta( x[ i ] ) );
}
```
[dirac-delta-function]: https://en.wikipedia.org/wiki/Dirac_delta_function
