MATLAB: Free hand drawing in Matlab with output is XY coordinate of trajectory.

freehand draw

How i can free draw any trajcetory with the output is the XY coordinate of trajectory like in the picture. I just try to find in the answer in form but did no find any answers satisfiing the requirement. Tks you for any answer. 2.png

Best Answer

This might be what you're looking for. ginput() allows you to click on a graph as many times as you'd like and it returns a 2-column matrix of x,y coordnates where you clicked.
Demo 1
Run this, click around the axes, press Enter to see where you clicked. xy will be the coordinate of your clicks. 
figure
xy = ginput(); % now click as many coordinates as you'd like then press Enter when finished. 
plot(xy(:,1), xy(:,2), 'bo', 'MarkerSize', 8, 'MarkerFaceColor', 'b');
Demo 2
This version plots as you click instead of plotting at the end. Press Enter to stop. xy will be the coordinate of your most recent click. 
figure
axh = axes;
hold(axh, 'on')
xy = [0,0];
while ~isempty(xy)
    xy = ginput(1);
    if ~isempty(xy)
        plot(axh, xy(1), xy(2), 'bo', 'MarkerSize', 8, 'MarkerFaceColor', 'b');
    end
end
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