Neat enclosed area for a group of points on a plane

8 次查看（过去 30 天）

显示更早的评论

Andrew Sol 2023-1-20

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1897610-neat-enclosed-area-for-a-group-of-points-on-a-plane

评论： Andrew Sol 2023-1-24

采纳的回答： Matt J

Data.mat

在 MATLAB Online 中打开

Hello!

I will be happy and grateful for help. I need to find the entire enclosed area in a dataset. For example, as you see in the picture (data attached)

I need to find some way to search for the closed area. I tried using the polygen command but it results in wrong areas.

pgonAll = polyshape(P(:,1),P(:,2),'Simplify',false);
pgonAll = simplify(pgonAll);
pgonEach = regions(pgonAll);
figure
plot(P(:,1),P(:,2))
hold on
plot(pgonEach(2))
legend({'P','pgonEach(2)'},'FontSize',12)

Do you have any Idea how can i handle it?

采纳的回答

Matt J 2023-1-20

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1897610-neat-enclosed-area-for-a-group-of-points-on-a-plane#answer_1152705

编辑：Matt J 2023-1-20

在 MATLAB Online 中打开

Data.mat

Your attached Data.mat looks like it contains different Data from your posted figure illustrations.

load Data

shp=alphaShape(Data,0.2);

Warning: Duplicate data points have been detected and removed.

[bf,V] = boundaryFacets(shp);

pgon=polyshape(V);

Warning: Polyshape has duplicate vertices, intersections, or other inconsistencies that may produce inaccurate or unexpected results. Input data has been modified to create a well-defined polyshape.

plot(Data(:,1),Data(:,2),'o');hold on

plot(pgon,'FaceColor','none'); hold off

axis([0.4,0.6,0.4,0.6])

9 个评论
显示 7更早的评论隐藏 7更早的评论

Andrew Sol 2023-1-24

Thanks for the recommendation! This command seems to work. It's not perfect, but it's a significant improvement nonetheless. I also found the "bwboundaries" command. What do you think of her?

Matt J 2023-1-24

编辑：Matt J 2023-1-24

You're welcome, but please Accept-click the answer if you decide that it is the one you will go with.

bwboundaries is for image data, which you do not have. There are ways, I'm sure, that you could construct an image from the points you've shown, but you would still face the same problem as with the methods discussed so far. Namely, you would need some way to seal the gaps between points before bwboundaries could give you what you want, and that would require judgements (as any method would) about which gaps need to be sealed and which ones are legitimate boundaries of the shape.

请先登录，再进行评论。