Rotating X and Y coordinates with a certain angle.

Hello,

I have a 7162176x2 array of cells that represent Cartesian coordinates. Column 1 is X, Column 2 is Y. I am trying to rotate these coordinates by 10 degrees clockwise.

I have read through matrix rotation, vector rotation and point rotation and from what I gather I need to create a rotation matrix and then multiply all my sets of points with it. This is what I have concluded to work with (I am including the before and after steps to make it easier to understand):

clear all
% SORT EXPORT IN THE SAME MANNER AS A .PRM FILE
m=csvread('file.csv',1,0); %REMOVE HEADER

%---------------------------------
%ORDER COLUMNS
n=m(1:end,[7 8 9 1]); %PICK DESIRED CELLS TO USE FOR OUTPUT
coordT=n(1:end,[1 2]); %GET X AND Y TO ROTATE

%ROTATION
theta=-10; %TO ROTATE CLOCKWISE BY X DEGREES
R=[cosd(theta) -sind(theta); sind(theta) cosd(theta)]; %CREATE THE MATRIX
rotcoord=R*coordT; %MULTIPLY VECTORS BY THE ROT MATRIX

%REPLACE X and Y columns on n with rotcoord X and Y

However it seems that the dimensions don't match. Am I approaching this the right way?

Apologies if this is something very simple that I am missing,

Thank you,

Pavlos

Answer 1

[Bruno Luong]

rotcoord=coordT*R'

[Pavlos Farangitakis]

Thank you very much! It seems to be working just fine with this!