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Topic: Quicker way to rotate a 3 dimensional array?
Replies: 2   Last Post: Jan 28, 2013 2:31 AM

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 Bruno Luong Posts: 9,811 Registered: 7/26/08
Re: Quicker way to rotate a 3 dimensional array?
Posted: Jan 28, 2013 2:31 AM

"Phil " <matlab@test.com> wrote in message <ke4thb\$s7j\$1@newscl01ah.mathworks.com>...
> I've got an array that is three dimensional where the first two dimensions are relatively large numbers and the third has length 3. This third one contains x,y,z co-ordinates that I would like to rotate about the x axis. I've managed to do this using:
>
> tmp3 = tmp;
> k = 0;
> for i=1:height
> for j=1:width
> k = k + 1;
> tmp3(i,j,:) = reshape(tmp(i,j,:),1,3)*[1,0,0;0,cos(theta),sin(theta);0,-sin(theta),cos(theta)];
> end
> end

R = [ 1,0,0; 0,cos(theta),sin(theta); 0,-sin(theta),cos(theta)]

[nx ny nz] = size(temp);
temp3 = reshape(reshape(temp,[],3)*R, [nx ny 3]);

% Bruno

Date Subject Author
1/27/13 Roger Stafford
1/28/13 Bruno Luong