difference method
Returns the difference between two coordinates as a new goog.math.Coordinate3.
@param {goog.math.Coordinate3} b A Coordinate3. @return {!goog.math.Coordinate3} A Coordinate3 representing the difference between {@code a} and {@code b}.
Implementation
Coordinate3 difference(Coordinate3 b)
{
return new Coordinate3(this.x - b.x, this.y - b.y, this.z - b.z);
}