MATLAB: Function to find points in pointcloud

find function

Hi all

My issue is that i have a big pointbloud in XYZ coord. Ive got 2 XYZ points, where i need to find all the points in the cloud, which is between this two given points. Does anyone know which kind of funktion i need to use for this? i have tried the find-function, but couldent get it to work.

thanks in advance.

Best Answer

So you have a scattering of points in 3D space, specified by an N by 3 array of [x,y,z] coordinates, right? Now, exactly what does it mean if a point is "between" two arbitrary points somewhere in 3D space? Do you want to connect those two points with a vector, then consider two planes (one at each point) that is normal to the vector, and then any points that are between the two planes are "in between" the points? Or do you have another definition?

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MATLAB: Create multiple spheres at given coordinates using a for loop or function and function call

You can use this code:

xyz = [-8.67212090030965	-7.78294481282592	4.19809966191787
4.30363429770975	-6.33796132936349	2.30412196271579
11.4626419696253	3.31049523749869	2.84193335035400
1.28757516363600	6.20802478748340	11.1358580308193]
x1 = xyz(:, 1);
y1 = xyz(:, 2);
z1 = xyz(:, 3); 
SizeXYZ = size(xyz,1);
for i = 1:SizeXYZ
  [x,y,z] = createspheres(x1(i),y1(i),z1(i));
  surf(x,y,z);
  hold on
end
%
function [X,Y,Z] =createspheres(spherex, spherey, spherez)
[x, y, z] = sphere(20);
X= x+ spherex;
Y = y+ spherey;
Z = z+spherez;
%newroot
end

MATLAB: How to find two points in a defined distance

Try pdist2() with this (untested) code:

% Put x and y column vectors together into a single array.
xy = [x, y];
% Find distance of every point to every other point.
d = pdist2(xy, xy); 
% Find distance closest to "r".
minDistance = min(abs(r - d));
% Find indexes of which pair is the closest.
[rows, columns] = find(d == minDistance);

Best Answer

Related Solutions

MATLAB: Create multiple spheres at given coordinates using a for loop or function and function call

MATLAB: How to find two points in a defined distance

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