Large amount of coordinates transformation in 3D

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Hello,
I am trying to perform transformation of large amount of coordinates, but firstly I am doing it on this small example:
I would like to rotate by 10 degrees about y axis x y z coordinates ( size is 8 x 3). How to perform such rotation? I have found rotation matrices but they are 3x3 and if I want to mupliply matrices [3x3] * [8x3] it is not possible.
Therefore I would like to ask you for help.
theta = 10;
A = [0 0 0; 1 1 1; 0 0 1; 1 1 0; 1 0 1; 0 1 0; 0 1 1; 1 0 0];
x = A(:,1); y = A(:,2); z = A(:,3);
RY = [
cosd(theta) 0 sind(theta)
0 1 0;
-sind(theta) 0 cosd(theta)];
ARY = RY*A;
Best regards
Michal

Accepted Answer

Chunru
Chunru on 13 Jul 2022
Transpose A:
theta = 10;
A = [0 0 0; 1 1 1; 0 0 1; 1 1 0; 1 0 1; 0 1 0; 0 1 1; 1 0 0]';
x = A(:,1); y = A(:,2); z = A(:,3);
RY = [
cosd(theta) 0 sind(theta)
0 1 0;
-sind(theta) 0 cosd(theta)];
ARY = RY*A
ARY = 3×8
0 1.1585 0.1736 0.9848 1.1585 0 0.1736 0.9848 0 1.0000 0 1.0000 0 1.0000 1.0000 0 0 0.8112 0.9848 -0.1736 0.8112 0 0.9848 -0.1736
A
A = 3×8
0 1 0 1 1 0 0 1 0 1 0 1 0 1 1 0 0 1 1 0 1 0 1 0

More Answers (1)

Walter Roberson
Walter Roberson on 13 Jul 2022
theta = 10;
M = makehgtform('yrotate', deg2rad(theta))
M = 4×4
0.9848 0 0.1736 0 0 1.0000 0 0 -0.1736 0 0.9848 0 0 0 0 1.0000
A = [0 0 0; 1 1 1; 0 0 1; 1 1 0; 1 0 1; 0 1 0; 0 1 1; 1 0 0];
x = A(:,1); y = A(:,2); z = A(:,3);
c = zeros(size(x));
xyzc = [x, y, z, c];
newxyz = xyzc * M
ans = 8×4
0 0 0 0 0.8112 1.0000 1.1585 0 -0.1736 0 0.9848 0 0.9848 1.0000 0.1736 0 0.8112 0 1.1585 0 0 1.0000 0 0 -0.1736 1.0000 0.9848 0 0.9848 0 0.1736 0
newx = newxyz(:,1); newy = newxyz(:,2); newz = newxyz(:,3);

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