set of points form a polygon?
5 views (last 30 days)
Show older comments
Hello,
Is there a way to tell if a set of vertices can form a closed polygon or not in genear or in matlab ?
Example:
[1,1], [3,1],[2,2] form a triangle when connected.
How do you conclude that these points can form a polygon.
Is there any algorithm to follow ?.
Thank you.
2 Comments
KSSV
on 24 Aug 2020
Always more than two non-collinear points can form a polygon. If they are on striaght line/ collinear they cannot and this can be obtained by using area; you can use polyarea to get the area. If area is zero then they are collinear. If you have a value they can form polygon.
Accepted Answer
Bruno Luong
on 24 Aug 2020
Edited: Bruno Luong
on 24 Aug 2020
If your list of points are ordered of the boundary of the polygonal, you can detect if the list of points self intersect thus NOT represent a valid polygonal by using polyshape, catch the warning or get the number of regions, if it's larger than 1 it's not valid:
EDIT: you can also use ISSIMPLIFIED function
>> x=rand(1,5)
x =
0.1419 0.4218 0.9157 0.7922 0.9595
>> y=rand(1,5)
y =
0.6557 0.0357 0.8491 0.9340 0.6787
>> issimplified(polyshape(x,y,'Simplify',false))
ans =
logical
0 % <= NOT VALID
More Answers (0)
See Also
Categories
Find more on Elementary Polygons in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!