Matlab: Plot points and make them clickable to display informations about it

Question

I have some points like this:

matrix = rand(6, 4)
0.8147    0.2785    0.9572    0.7922
0.9058    0.5469    0.4854    0.9595
0.1270    0.9575    0.8003    0.6557
0.9134    0.9649    0.1419    0.0357
0.6324    0.1576    0.4218    0.8491
0.0975    0.9706    0.9157    0.9340

the first two columns are x and y values which get plotted as points via

plot(matrix(:, 1), matrix(:, 2), '*r'

Now what I want to work out is the following: Whenever I click on a certain point in the plot, I want the information out of column 3 and 4 being displayed as text just right of the point in a box, e.g. with some text, e.g. information 1: VALUE_COL3, information 2: VALUE_COL4. How to achieve that? I thought of the ButtonDownFcn attribute and than check out the clicked point and match it. But is there any easier way to do it?

Thanks!

Answer 1

While Sam's method is probably the correct solution here, I'd like to offer another one (although it is more of a 'hack' than a proper solution).

You can attach context menus to handle graphics objects. These menus can display multiple selections and even let your script respond to user selections. Take a look at the following example:

x = [1:10];
y = x.^2;

plot(x,y); hold on;
h = plot(x(5), y(5),'ro'); %% save the handle to the point we want to annotate

hcmenu = uicontextmenu;
item1 = uimenu(hcmenu, 'Label', 'info 1');
item2 = uimenu(hcmenu, 'Label', 'info 2');
item3 = uimenu(hcmenu, 'Label', 'info 2');

set(h, 'uicontextmenu', hcmenu);

When you right click on the 'o' point, you get the context menu:

More information can be found at the Mathwork's site.