Data extract from graph.

I have a plot I created in matlab using excel data. I would like my code to provide a Y value for the X value that I provide. Is this possible? Please note that i cannot look for the Y value, the code should automatically assign the Y value from the graph for provided X value.

Thanks for the Help.

Answer 1

[Walter Roberson]

Providing that x is monotonic:

h = findobj(gca, '-property', 'XData');
hx = h.XData;
hy = h.YData;
[shx, idx] = sort(hx);
shy = hy(hx);

corresponding_y = interp1(shx, shy, given_x);