function cauchy2( x0, gamma ) {
		if (
			isnan( x0 ) ||
			isnan( gamma ) ||
			gamma <= 0.0
		) {
			return NaN;
		}
		return cauchy0( rnorm, x0, gamma );
	}
Returns pseudorandom number drawn from a Cauchy distribution.

@private
@param {number} x0 - location parameter
@param {PositiveNumber} gamma - scale parameter
@returns {number} pseudorandom number

@example
var v = cauchy2( 0.0, 2.0 );
// returns <number>

@example
var r = cauchy2( 1.0, -1.5 );
// returns NaN