Finding and plotting evenly-spaced points along a vector

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I've plotted a centerline along an ellipse in my image by using ginput to select 2 points and then drawing the line connecting them. Next, I would like to figure out the coordinates of 10 evenly spaced points along this line and plot them on top of the current image, creating a spine of 12 points (10 + the 2 original) along the ellipse. How would I implement this? The ultimate goal is to create 11 even-length vectors, one between every 2 points along the spine. My current code is below:
I = data(:,:,i);
imshow(I, []);
hold on
[x, y] = ginput(2);
plot(x, y, '*')
pause(1);
plot(x, y, 'r')
pause(1)
hold off
pause(5);
close all

Accepted Answer

Federico Becattini
Federico Becattini on 5 Nov 2015
If I understood correctly this is what you are looking for:
num_points = 10;
for i=1:num_points
points_x(i)=(x(1)*i+x(2)*(num_points-i+1))/(num_points+1);
points_y(i)=(y(1)*i+y(2)*(num_points-i+1))/(num_points+1);
end
plot(points_x, points_y, '*c')
By changing num_points you can choose the number of points to plot along the line.

More Answers (1)

dpb
dpb on 5 Nov 2015
Alternate way given the two end points [x,y]--
xy=[linspace(x(1),x(2),12).' linspace(y(1),y(2),12).'];
returns the points in two columns.

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