function diracDeltaf( x ) {
	if ( isnanf( x ) ) {
		return NaN;
	}
	if ( x === 0.0 ) {
		return PINF;
	}
	return 0.0;
}
Evaluates the Dirac delta function for a single-precision floating-point number.

@param {number} x - input value
@returns {number} function value

@example
var v = diracDeltaf( 0.0 );
// returns Infinity

@example
var v = diracDeltaf( 3.14 );
// returns 0.0

@example
var v = diracDeltaf( NaN );
// returns NaN