How to find local peaks in a 3D plane

Question

Suzan Wulms 2021-6-30

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/868893-how-to-find-local-peaks-in-a-3d-plane

回答： Akira Agata 2021-7-2

positionsplane.mat

Hello all,

I have a problem in automatically detection of 4 quite obviously present peaks. I transformed my data to a almost flat plane with four peaks in z-direction. I want to automatically detect the locations and corresponding datapoints of the 4 peaks. Does someone know how to solve this problem? I've added my data.

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

dpb 2021-6-30

You could help by supplying the code to do what you've done so far and by telling us what, specifically is the data in the .mat file -- original, transformed by whatever it is you described, ...???

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Akira Agata 2021-7-2

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/868893-how-to-find-local-peaks-in-a-3d-plane#answer_738333

在 MATLAB Online 中打开

How about the following?

% Load data
load('positionsplane.mat');
% Arrange it as a table variable
tData = array2table(positionsplanenew,'VariableNames',{'x','y','z'});
% Extract z > 15
idx = tData.z > 15;
tData2 = tData(idx,:);
% Apply k-means clustering
rng('default');
g = kmeans(tData2{:,:},4);
tData2.group = g;
% Find maximam points for each cluster
peaks = splitapply(@max, tData2.z, tData2.group);
idx = ismember(tData2.z, peaks);
% Visualize the result
figure
scatter3(tData.x, tData.y, tData.z, '.')
hold on
scatter3(tData2.x(idx), tData2.y(idx), tData2.z(idx),'r','filled')