comp.lang.idl-pvwave archive: archive » sort points clockwise or clounterclockwise

Home » Public Forums » archive » sort points clockwise or clounterclockwise

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

sort points clockwise or clounterclockwise [message #91141]

Mon, 08 June 2015 13:32

junsix
Messages: 3
Registered: June 2015

Junior Member

Hi,

I am trying to order points of closed polygon in clockwise or counterclockwise.
Here is a octagon and I tried to use Triangulate that I searched.

2 0
6 3
4 5
1 7

IDL> x=[3.,2.,2.,4.,1.,4.,1.,3.]
IDL> y=[4.,1.,4.,3.,2.,2.,3.,1.]
IDL> TRIANGULATE, X, Y, Triangles
IDL> help,triangles
TRIANGLES LONG = Array[3, 6]
IDL> print,triangles
4 1 7
4 7 6
6 7 2
2 7 5
2 5 3
2 3 0

The Triangulate returns each triangles in clockwise, while points in each triangles in counterclockwise.
But, what I need is to order points in clockwise or counterclockwise, e.g. 146203571 or 75302641, and then make polygon to calculate area and perimeter.
Thank you in advance.

Jun

Report message to a moderator

[Message index]

		sort points clockwise or clounterclockwise By: junsix on Mon, 08 June 2015 13:32
		Re: sort points clockwise or clounterclockwise By: Craig Markwardt on Tue, 09 June 2015 09:19
		Re: sort points clockwise or clounterclockwise By: junsix on Tue, 09 June 2015 13:11

Previous Topic:	buggy dictionary
Next Topic:	Experience with ENVIRasterSeries?

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Wed Oct 08 11:49:55 PDT 2025

Total time taken to generate the page: 0.00198 seconds