本帖最后由 作者 于 2009-4-18 16:12:26 编辑
 - ;判断圆弧是优弧还是劣弧
- (defun c:test()
- (while (setq ent (car (entsel "\n选取圆弧:")))
- (if (= (cdr (assoc 0 (setq db (entget ent)))) "ARC")
- (progn
- (setq ta (- (cdr (assoc 51 db)) (cdr (assoc 50 db))))
- (if (< ta 0) (setq ta (+ ta (* 2.0 pi))))
- (alert (strcat "所选取的圆弧是" (if (>= ta pi) "优弧" "劣弧")))
- )
- (alert "所选取的不是圆弧!")
- )
- )
- )
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