how can I rotate the ellipses based on the orientation angle of (x_i,y_i)?

4 views (last 30 days)
Noob
Noob on 16 Jun 2017
Answered: Giulio Antufermo on 14 Jan 2020
I would like to rotate the ellipses to show the orientation, theta, of the centered data points.

Accepted Answer

KSSV
KSSV on 16 Jun 2017
a=5; % horizontal radius
b=10; % vertical radius
x0=0; % x0,y0 ellipse centre coordinates
y0=0;
t=-pi:0.01:pi;
x=x0+a*cos(t);
y=y0+b*sin(t);
plot(x,y)
hold on
%%Rotate the ellipse by 90 degrees
th = pi/2 ;
R = [cos(th) -sin(th) ; sin(th) cos(th)] ;
% Rotate all the points
P = zeros(2,length(x)) ;
for i =1:length(x)
P(:,i) = R*[x(i) ;y(i)] ;
end
xr = P(1,:) ; yr = P(2,:) ;
plot(xr,yr,'r')
  3 Comments
KSSV
KSSV on 16 Jun 2017
YOu have to run it in a loop....
for i = 1:length(x_i) ;
P(:,i) = R * [x_i(i) ; y_i(i)];
end

Sign in to comment.

More Answers (1)

Giulio Antufermo
Giulio Antufermo on 14 Jan 2020
It didn't really work for me

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!