How can I view the formatted date string(DATESTR) while using Date Cursor for a plot containing date strings on MATLAB 8.1(R2013a)?

When I plot a date with some data, it seems I have to pass in DATENUM instead of DATESTR to the plot function. Thus, when I click on the data point, I see a DATENUM value, not a straight forward DATESTR that I can understand. Is there a way in which I can display the readable DATESTR format?

Answer 1

[MathWorks Support Team]

A simple way to achieve this is to change the display format in the UpdateFcn of the Data Cursor.

Consider the following command which plots the date value on the x-axis:

plot(datenum(dateVal), yValue);

Create a Data Cursor object as follows:

dcm_obj = datacursormode(gcf);

You need to assign a callback function to UpdateFcn. Let's call this MYFUNCTION. MYFUNCTION specifies how the data cursor tooltip should display the coordinate values.

set(dcm_obj, 'UpdateFcn',@myfunction);

In MYFUNCTION specifu the display format as DATESTR for the appropriate coordinate(in this case, x-coordinate.)

function output_txt = myfunction(obj,event_obj)
% Display the position of the data cursor
% obj          Currently not used (empty)
% event_obj    Handle to event object
% output_txt   Data cursor text string (string or cell array of strings).

pos = get(event_obj,'Position');
output_txt = {['X: ', datestr(pos(1))],...                            % Notice the X coordinate value has been changed to DATESTR
    ['Y: ',num2str(pos(2),4)]};

% If there is a Z-coordinate in the position, display it as well
if length(pos) > 2
    output_txt{end+1} = ['Z: ',num2str(pos(3),4)];
end