MATLAB: How can I rotate the ellipses based on the orientation angle of (x_i,y_i)

dataplotting

I would like to rotate the ellipses to show the orientation, theta, of the centered data points.

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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')

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MATLAB: I need help to plot circle around the points and these points are in a circle. please response

n=10; % number of points that you want
    center = [2 ,2]; % center coordinates of the circle [x0,y0] 

    radius = 10; % radius of the circle

      angle = 2*pi*rand(n,1);
      r = radius*sqrt(rand(n,1));
     X = r.*cos(angle)+ center(1);
     Y = r.*sin(angle)+ center(2);
     plot(X,Y,'.r')
     hold on
     %%Draw circle 
     R = 1. ;  % radius 
     th = linspace(0,2*pi) ;
     for i = 1:length(X)
         x = R*cos(th)+X(i) ;
         y = R*sin(th)+Y(i) ;
         plot(x,y,'b')
     end
     hold on
     center = [2 ,2]; % center coordinates of the circle [x0,y0] 
    radius = 10; % radius of the circle
    angle = 0:.01:2*pi;
    r = radius;
       X = r.*cos(angle)+ center(1);
       Y = r.*sin(angle)+ center(2);
     plot(X,Y,'.b')

MATLAB: Rotation of the circle (points)

Just add an increment to the th

th = linspace(0,2*pi,10) + rotation_angle ;

Best Answer

Related Solutions

MATLAB: I need help to plot circle around the points and these points are in a circle. please response

MATLAB: Rotation of the circle (points)

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