x方向上非线性放大圆思路，请帮忙修改，谢谢！

linear

x方向上非线性放大圆思路，请帮忙修改，谢谢！
请教：这是一个在x,方向上非线性放大圆思路，因为知识有限，请大虾们帮忙修改。谢谢！
这个非线性方程是关于同样纵坐标下，圆上两点横坐标的差值(它是变量，即不同的y,差值不同)。

(defun testbb (/ obj circle )
(vl-load-com)
(setq obj (vlax-ename->vla-object (car (entsel "\npick the circle: "))))
   
(setq rad (vla-get-radius obj));get the radius of circle
(setq cen (vla-get-center obj));here center is (0,0,0)
(setq pt (vla-get-point circ-obj);get the points of circle
      
if for (cadr pt(i))=(cadr pt(+(i)n);for the same y coordinate of two different points on circle
(setq leng ( abs(-(car pt(i))(car pt(+(i)n)))));calculate the subtraction of their x coordinates
(setq leng1 (+(expt leng 2)1);bring the subtraction into nonlinear function to largen
(setq newx (/ leng1 2);then divide by 2
(setq newx1 (- newx)      
(vlax-put-property newx1 (car pt(i));take above value as new x coordinates of that two points,put back negative one to point1
(vlax-put-property newx (car pt(+(i)n)));put back positive one to point2
                                        ;here short of one line: according to those points,get a polyline.
  (command "_.extrude" (entlast) "" z "");extrude the polyline at a height to get cylinder
  
  (prompt "\nblock has been scaled.")
  (princ)
)