[编程交流] 计算最大z值

(setq P1 (getpoint "\nDistance From "))
   (setvar "OSMODE" 128)
   (setq DR (getdist P1 "\nPer to "))
   (setq DS (rtos DR 2 6))

;point to line 
(defun hp:ptol (p 2p 3d / ad d pp) ; hanhphuc - 29.10.2015
   (setq ad (mapcar '(lambda (f) (apply f (mapcar ''((x) (list (car x) (cadr x))) 2p)))
             '(angle distance)
             ) ;_ end of mapcar
  d  (vxv (mapcar '- p (car 2p)) (mapcar ''((f) (f (car ad))) (list cos sin)))
  pp (polar (car 2p) (car ad) d)
  ) ;_ end of setq
   (if        (<= 0. d (cadr ad))
     (list (distance p pp)
    (list (car pp)
          (cadr pp)
          (if 3d
            (+ (* (/ (apply '- (mapcar 'last (reverse 2p))) (cadr ad)) d) (caddr (car 2p)))
            (caddr p)
            ) ;_ end of if
          ) ;_ end of list
    ) ;_ end of list
     ) ;_ end of if
   ) ;_ end of defun
;function call
;(hp:ptol pt lst 3d) 
;pt= point
;lst= list of 2 end points
;example: (list p1 p2 )
;3d= t / nil
;Returns list 
;( d ( x y z )) 
;Where d=2d distance p to line from p1->p2
;(x y z) is coordinates apparently "perpendicular" from pt on line
;;;;example:
;;;(setq p1 (-131.868 17.4786 8.12106)
;;;      p2 (-142.847 5.87031 -2.51656)
;;;      p3 (-128.05 26.4743 2.99644)
;;;      ) ;_ end of setq
;(hp:ptol p1 (list p2 p3) t)
;return (2.14588 (-133.611 18.7304 0.9244))
;(hp:ptol p1 (list p2 p3) nil)
;returns (2.14588 (-133.611 18.7304 8.12106))
;; Vector Dot Product  -  Lee Mac
;; Args: u,v - vectors in R^n
(defun vxv ( u v )
   (apply '+ (mapcar '* u v))
)