[求助]：如何在多段线实现倒凹角操作

xiahwan

我在论坛中下载了一个倒凹角的程序经测试不能进行多段线操作，敬请高手帮忙改进一下。
附程序：
(DEFUN c:by ( / ename1 ename2 rad basrad enlast PT1 PT2 ang ang1 ang2 ptc)
   (setq ename1 (entsel "\n请选择对象1")
  ename2 (entsel "\n请选择对象2")
  rad    (getreal "\n请输入半径:")
   )
  (if (and rad ename1 ename2 (not (eq ename1 ename2)))
     (progn
       (setq basrad (getvar"filletrad"))
       (setvar "filletrad" 1)
       (command ".fillet" ename1 ename2)
       (setq enlast (entlast) DXF (ENTGET ENLAST))
       (if (= "ARC" (CDR (ASSOC 0 DXF)))
  (PROGN
    (SETQ PT1 (POLAR (CDR (ASSOC 10 DXF)) (CDR (ASSOC 50 DXF)) (CDR (ASSOC 40 DXF))))
    (SETQ PT2 (POLAR (CDR (ASSOC 10 DXF)) (CDR (ASSOC 51 DXF)) (CDR (ASSOC 40 DXF))))
    (command "_.erase" enlast "")
    (setq ang1 (CDR (ASSOC 50 DXF)) ang2 (CDR (ASSOC 51 DXF)))
    (if (> ang1 ang2)
      (setq ang1 (- ang1 (* pi 2.0)))
    )
    (setq ang (/ (- ang2 ang1) 2))
    (setvar "filletrad" (/ rad (/ (sin ang) (cos ang))))
    (command ".fillet" ename1 ename2)
           (setq enlast (entlast) DXF (ENTGET ENLAST))
    (SETQ PT1 (POLAR (CDR (ASSOC 10 DXF)) (CDR (ASSOC 50 DXF)) (CDR (ASSOC 40 DXF))))
    (SETQ PT2 (POLAR (CDR (ASSOC 10 DXF)) (CDR (ASSOC 51 DXF)) (CDR (ASSOC 40 DXF))))
    (setq ptc (POLAR (CDR (ASSOC 10 DXF)) (+ ang1 ang) (/ (CDR (ASSOC 40 DXF)) (cos ang))))
    (command "_.arc" "c" ptc pt2 pt1)
    (command "_.erase" enlast "")
  )
       (setvar "filletrad" basrad)
       )
     )
    )
  (princ)
   )


高手们 请帮忙啊