comp.lang.idl-pvwave archive: archive » Re: find a plane in a 3D plot

Home » Public Forums » archive » Re: find a plane in a 3D plot

Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend

Re: find a plane in a 3D plot [message #62495 is a reply to message #62488]

Fri, 12 September 2008 07:47

Wox
Messages: 184
Registered: August 2006

Senior Member

On Fri, 12 Sep 2008 02:54:09 -0700 (PDT), Nicola
<nicola.vianello@gmail.com> wrote:

> I have to find a
> way to identify this plane and the direction perpendicular to this
> plane in the more accurate way as possible.

The code below is one way of doing things. The resulting plane is
defined with a normal vector and a point.

pro test
x=[1.,0,1,2,3,4]
y=[0.,1,1,2,3,4]
z=[2.,2,2,2,2,2]

; Orthogonal distance regression
; check e.g. http://mathforum.org/library/drmath/view/63765.html

; Centroid: orthogonal distance
; regression plane goes through it
n=n_elements(x)
data=transpose([[x],[y],[z]])
centroid=total(data,2)/n

data[0,*]-=centroid[0]
data[1,*]-=centroid[1]
data[2,*]-=centroid[2]

SVDC, data, W, U, V

smallest_singularvalue=min(W,ind)
plane_normal=reform(V[ind,*])

print,'Orthogonal distance regression plane'
print,'1. goes through: ',centroid
print,'2. has normal: ',plane_normal
end;pro test

Report message to a moderator

[Message index]

		Re: find a plane in a 3D plot By: Nicola on Fri, 12 September 2008 09:20
		Re: find a plane in a 3D plot By: Wox on Fri, 12 September 2008 07:47
		Re: find a plane in a 3D plot By: David Fanning on Fri, 12 September 2008 07:29
		Re: find a plane in a 3D plot By: Brian Larsen on Fri, 12 September 2008 06:59
		Re: find a plane in a 3D plot By: pgrigis on Fri, 12 September 2008 06:45
		Re: find a plane in a 3D plot By: Wox on Mon, 22 September 2008 02:15

Previous Topic:	map_set problem
Next Topic:	find a plane in a 3D plot

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Wed Oct 08 19:33:20 PDT 2025

Total time taken to generate the page: 0.00515 seconds