public override String ToString() { String s = String.Format ("xx:{0:##0.0#} yx:{1:##0.0#} xy:{2:##0.0#} yy:{3:##0.0#} x0:{4:##0.0#} y0:{5:##0.0#}", this.Xx, this.Yx, this.Xy, this.Yy, this.X0, this.Y0); return s; }