请问，如何求某一点到一pl线的距离

alin · 发表于 2002-10-31 06:37:00

Trying to snap to a polyine (or other curve) at its bending point to get the distance is not applicable in this question.

Your routine can surely get the closest point at the curve, no worry about the start point or the end point. Howerver, we have to make sure we are in a WCS, otherwise we will get it wrong. What do you reckon?

龙龙仔 · 发表于 2002-10-31 11:58:00

(defun pttoline_dist (/ WW QQ SS)
  (setq SS (car (entsel "\n选择线: ")))
  (setq WW (getpoint "\n选择点: "))
  (setq QQ (vlax-curve-getclosestpointto
      (vlax-ename->vla-object SS)
      WW
      t
   )
  )
  (distance WW QQ)
)

龙龙仔 · 发表于 2002-11-1 12:24:00

龙龙仔 · 发表于 2002-11-1 12:32:00

alin · 发表于 2002-11-1 13:33:00

alin · 发表于 2002-11-1 13:36:00

龙龙仔 · 发表于 2002-11-1 16:07:00

wltools · 发表于 2004-4-14 09:48:00

点到直线（无限长）距离：只用点间的距离，就成了平面问题，然后求夹角，用夹角求点、线距离。 (defun p-line-dis (p ;点
end1 ;线端点1
end2 ;线端点2
/
angcos ;线p end1 和线end2 end1的夹角的cos
disp-1 ;p 和 end1 间距离
disp-2 ;p 和 end2 间距离
dis1-2 ;end1 和 end2 间距离.
tem
)
(setq disp-1 (distance p end1)
disp-2 (distance p end2)
dis1-2 (distance end1 end2))
(setq angcos (/ (+ (expt disp-1 2.0) (expt dis1-2 2.0) (* -1.0 (expt disp-2 2.0))) 2.0 disp-1 dis1-2))
(setq tem (- 1.0 (expt angcos 2.0))
tem (sqrt tem)
tem (* disp-1 tem)
)
tem
)
(p-line-dis (getpoint) (getpoint) (getpoint)) 看到此贴临时写的，没有足够验证。如果求点到线段的距离可以根据angcos求垂直点。

无痕 · 发表于 2004-4-15 00:30:00

用龙龙仔的就很好了么

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请问，如何求某一点到一pl线的距离

不是这个意思，是点到直线（或直线的虚拟延长线）的垂线的距离。

Trying to snap to a polyine at its bending point ...

here!!!

看不懂你要甚么?????传张图上来吧!!

我想ALIN是不会中文输入法,他应该是香港人吧!我明天也要回香港老家!!!

sorry

I thought you were from Taiwan. How do you know simplified Chinese? hehe..

简体看多了就会习惯,我那些香港同学E_MAIL都是用英文,他们就不会学学中文输入????