Plot only the outermost nodes

Hello! I would like to fix my code in such a way that I get only the outermost nodes. How can I do this? Shown is an example of what I have achieved and what I want to achieve. Thanks in advance for any answers!

<-- result obtained

<-- expected result

X = readmatrix('test_9.txt');
% X = readmatrix('test_222.txt');
%% Run DBSCAN Clustering Algorithm
epsilon = 5;
MinPts = 2;
IDX=DBSCAN(X,epsilon,MinPts);
%% Plot Results
out = PlotClusterinResult_mod(X, IDX);
title(['DBSCAN Clustering (\epsilon = ' num2str(epsilon) ', MinPts = ' num2str(MinPts) ')']);
% double check 'out' data (boundary points) are now in the workspace
figure
plot(X(:,1),X(:,2),'d');
hold on
plot(out(:,1),out(:,2),'*k');
hold off

Answer 1

[Mathieu NOE]

hello again

I think I already answered this in your other post

here again attached the new code

[Alberto Acri]

Thank you for the response @Mathieu NOE. I had seen it in the other post as well! Can I ask you for one last help? In the case of "particular" curves in attachment, the code with shrink_factor variation always leads to some small loss. Can you always get a good result as with other curves? Thank you very much!

[Mathieu NOE]

hello Alberto

see my answer in your other post

maybe you should close this one , as it keeps things a bit simpler to follow ?