find lines in an image in matlab

main.m
% Read the image
I = imread('myimage.jpg');

% Convert to grayscale
Igray = rgb2gray(I);

% Detect edges
edges = edge(Igray);

% Apply the Hough transform to detect lines
[H,theta,rho] = hough(edges);
peaks = houghpeaks(H, 10);
lines = houghlines(edges,theta,rho,peaks);

% Visualize the lines
figure, imshow(I), hold on
max_len = 0;
for k = 1:length(lines)
   xy = [lines(k).point1; lines(k).point2];
   plot(xy(:,1),xy(:,2),'LineWidth',2,'Color','green');

   % Plot beginnings and ends of lines
   plot(xy(1,1),xy(1,2),'x','LineWidth',2,'Color','yellow');
   plot(xy(2,1),xy(2,2),'x','LineWidth',2,'Color','red');

   % Determine the endpoints of the longest line segment
   len = norm(lines(k).point1 - lines(k).point2);
   if ( len > max_len)
      max_len = len;
      xy_long = xy;
   end
end
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