Kronecker Delta

Evaluate the Kronecker delta.

The Kronecker delta is defined as

delta Subscript i j Baseline equals StartLayout Enlarged left-brace 1st Row 1st Column 1 2nd Column if i equals j 2nd Row 1st Column 0 2nd Column if i not-equals j EndLayout

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/math/utils/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 ) );
}