# Kronecker Delta
> Evaluate the [Kronecker delta][kronecker-delta] (single-precision).
The [Kronecker delta][kronecker-delta] is defined as
## Usage
```javascript
var kroneckerDeltaf = require( '@stdlib/math/base/special/kronecker-deltaf' );
```
#### kroneckerDeltaf( i, j )
Evaluates the [Kronecker delta][kronecker-delta] (single-precision).
```javascript
var v = kroneckerDeltaf( 3.14, 3.14 );
// returns 1.0
v = kroneckerDeltaf( 3.14, 0.0 );
// returns 0.0
v = kroneckerDeltaf( NaN, 3.14 );
// returns NaN
v = kroneckerDeltaf( 3.14, NaN );
// returns NaN
v = kroneckerDeltaf( NaN, NaN );
// returns NaN
```
## Examples
```javascript
var linspace = require( '@stdlib/array/linspace' );
var kroneckerDeltaf = require( '@stdlib/math/base/special/kronecker-deltaf' );
var x = linspace( -1.0, 1.0, 101 );
var i;
for ( i = 0; i < x.length; i++ ) {
console.log( 'kronecker(%d,%d) = %d', x[ i ], 0.0, kroneckerDeltaf( x[ i ], 0.0 ) );
}
```
* * *
## C APIs
### Usage
```c
#include "stdlib/math/base/special/kronecker_deltaf.h
```
#### stdlib_base_kronecker_deltaf( i, j )
Evaluates the Kronecker delta (single-precision).
```c
float v = stdlib_base_kronecker_deltaf( 3.0f, 3.0f );
// returns 1.0f
```
The function accepts the following arguments:
- **i**: `[in] float` input value.
- **j**: `[in] float` input value.
```c
float stdlib_base_kronecker_delta( const float i, const float j );
```
### Examples
```c
#include "stdlib/math/base/special/kronecker_deltaf.h"
#include
int main() {
float x[] = { 3.0f, 4.0f, 5.0f, 5.0f };
float y;
int i;
for ( i = 0; i < 4; i += 2 ) {
y = stdlib_base_kronecker_deltaf( x[ i ], x[ i+1 ] );
printf( "kronecker_delta(%f, %f) = %f\n", x[ i ], x[ i+1 ], y );
}
}
```
[kronecker-delta]: https://en.wikipedia.org/wiki/Kronecker_delta
