Kronecker Delta

Evaluate the Kronecker delta.

The Kronecker delta is defined as

Usage

var kroneckerDelta = require( '@stdlib/math/base/special/kronecker-delta' );

kroneckerDelta( i, j )

Evaluates the Kronecker delta.

var v = kroneckerDelta( 3.14, 3.14 );
// returns 1.0

v = kroneckerDelta( 3.14, 0.0 );
// returns 0.0

v = kroneckerDelta( NaN, 3.14 );
// returns NaN

v = kroneckerDelta( 3.14, NaN );
// returns NaN

v = kroneckerDelta( NaN, NaN );
// returns NaN

Examples

var linspace = require( '@stdlib/array/base/linspace' );
var kroneckerDelta = require( '@stdlib/math/base/special/kronecker-delta' );

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, kroneckerDelta( x[ i ], 0.0 ) );
}

C APIs

Usage

#include "stdlib/math/base/special/kronecker_delta.h

stdlib_base_kronecker_delta( i, j )

Evaluates the Kronecker delta.

double v = stdlib_base_kronecker_delta( 3.0, 3.0 );
// returns 1.0

The function accepts the following arguments:

i: [in] double input value.
j: [in] double input value.

double stdlib_base_kronecker_delta( const double i, const double j );

Examples

#include "stdlib/math/base/special/kronecker_delta.h"
#include <stdio.h>

int main( void ) {
    const double x[] = { 3.0, 4.0, 5.0, 5.0 };

    double y;
    int i;
    for ( i = 0; i < 4; i += 2 ) {
        y = stdlib_base_kronecker_delta( x[ i ], x[ i+1 ] );
        printf( "kronecker_delta(%lf, %lf) = %lf\n", x[ i ], x[ i+1 ], y );
    }
}