MATLAB: GCA CurrentPoint with the DateTime Ticks on the X Axis

current pointdateticksdatetime

I am making a plot where the data is plotted vs Time (HH:MM:SS, for example). I want to be able to click on the plot and display the value of Y. I don't want to use the Data Cursor. I have in the past used the CurrentPoint property of the axes.
This usually returns the actual X and Y values from a mouse click but with the datetime ticks it does not return the actual X. I have tried searching the documentation but I am failing to find what it is outputting. I would like current point to output the value of X in datetime format.
Any ideas?
Thanks
Abhay

Best Answer

Because the CurrentPoint property stores x, y, and z all together in a single matrix, the CurrentPoint cannot reflect the mixed datetime, duration, and numeric data that may be present in the plot. Therefore, CurrentPoint always stores the numeric equivalent.

As Sebastian pointed out, you need to convert from numeric to datetime, but there is actually an easier (and documented) way to do this conversion: num2ruler (and the corresponding ruler2num).

ax(1) = subplot(121); 
DT = datetime(2001:2010, 1:10,1);
plot(DT, rand(length(DT),1)); grid on

ax(2) = subplot(122); grid on
DT = datetime(2018,2,3,4,5,12:.2:15);
plot(DT, rand(length(DT),1)); grid on

set(ax(1),'ButtonDownFcn',@(hax,e) disp(num2ruler(hax.CurrentPoint(1),hax.XAxis)))
set(ax(2),'ButtonDownFcn',@(hax,e) disp(num2ruler(hax.CurrentPoint(1),hax.XAxis)))
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