public void assign(VectorD2d vect) { this._x = vect.x; this._y = vect.y; }
public double dot(VectorD2d rhs) { return(this.x * rhs.x + this.y * rhs.y); }
public double cross(VectorD2d rhs) { return(this.x * rhs.y - this.y * rhs.x); }
public VectorD2d(VectorD2d v) : this(v.x, v.y) { }