求取面积

wandong · 发表于 2014-9-19 19:45:34

lisp如何通过选取内部点求取任意封闭区域的面积，比如区域为相交的直线或圆弧？就像图案填充自动查找边界，求取由边界包围部分的面积？

lsjj · 发表于 2014-9-19 20:21:14

用Bpoly
第二行補字

香田里浪人 · 发表于 2014-9-20 02:35:10

(defun c:dmj()
  (setvar "cmdecho" 0)
(setq cth (rtos (getvar "textsize")))
(setq TextHeight (getdist (strcat "\n输入标注文字高度 < " cth " > : ")))
(if (= TextHeight nil)(setq TextHeight cth))
(command "style" "tukou" "黑体" "0" "" "0" "" "")
(command "layer" "M" "面积单注" "C" "1" "" "LT" "CONTINUOUS" "" "");设置一个标注图层
  (defun maketext (txt pt) ; 生成文字子函数
(entmake (list '(0 . "TEXT")
   (cons 62 3)
   (cons 10 pt)
   (cons 40 TextHeight)
   (cons 1 txt)
   '(41 . 0.6)
      )
)
  )
  (setq pt (getpoint "\n选取点:"))
  (while pt
(setvar "cecolor" "1")
(command "bpoly" pt "")
(setq en (entlast))
(if (/= en nil)
   (progn
(command "area" "o" en)
(setq aa (getvar "area"))
(redraw en 3)
(setq bb (strcat "S=" (rtos aa 2 2 )"㎡"))
(setq pt1 (getpoint "请指定面积书写位置:"))
(command "_text" pt1 TextHeight "" bb 0)
)
   )
(entdel en)
(setvar "cecolor" "bylayer")
(setq pt (getpoint "\n选取点:"))
)
  (prin1)
  )

wandong · 发表于 2014-9-20 10:25:11

非常感谢lsjj 和香田里浪人的指导。

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[已解答] 求取面积