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# Miscalculation of new function "pcsegdist" in Matlab R2018b

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ha ha on 2 Mar 2019
Commented: ha ha on 9 Jul 2020
I try to test the new function "pcsegdist" in Matlab R2018b. However, the result is wrong for Segment point cloud into clusters based on Euclidean distance
Example: I test with 3D data points- 1797 points (please see attached test.txt file). It is noted that the smallest distance between 2 neighbor points is 0.3736
tic
clear;clc;filename = 'test.txt'; load('test.txt');P = test(:,1:3);%get data=coordinate(x,y,z) from set of data "column" at (all row & column 1,2,3)
ptCloud = pointCloud(P);
minDistance = 0.71;%this value should less than the smallest 3D distance between 2 clusters
[labels,numClusters] = pcsegdist(ptCloud,minDistance);%numClusters: the number of Cluster
%labels: is the kx1 matrix. This is index of each voxel in each cluster
toc
%% Generate the cell_cluster
cell_cluster={};x=P(:,1);y=P(:,2);z=P(:,3);
for i=1:numClusters
cluster_i=[x(labels==i),y(labels==i),z(labels==i)];%call x,y,z coord of all points which is belong the same cluster
cell_cluster{end+1} = cluster_i;%this is (1xk)cell. where k=number of cluster
end
figure;Plot_cell(cell_cluster);view(3);% plot result cluster(using function to plot) But when I verify by using manually method (ground truth data), the result should as below figure:  Thus, I wonder about the result of new function "pcsegdist" in Matlab R2018b, Or I misunderstand or I wrong somewhere ?
##### 3 CommentsShowHide 2 older comments
ha ha on 9 Jul 2020
As I described in my question: "the smallest 3D distance between 2 neighbor points is 0.3736". Thus, with parameter setting "minDistance = 0.71", this should be 1 cluster (not 2 clusters as the result of new function "pcsegdist" in Matlab R2018b)

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