Deleting plots within a GUI only if the plot exists?

How would I go about deleting specific plots within a GUI only if they exist? Thanks in advance. My code is below.

    function deleting_plots(source,eventdata)
        if exist('S.hDFplot1','plot')
        delete (S.hDFplot1);
        delete (S.hDFplot2);
        end

[Jan]

From where is this function called? It looks like a callback. What is "S"? What is the contents of "S.hDFplot1"?

[Adam]

If you have a finite number of plots that you are going to have at one time or another you can just declare a handle for each of them on your struct and initialise it to []

Then you don't need to care if it exists or not because calling delete on [] does not do any harm.

If you want to delete all plots then you could store all their handles in a single array of plot handles so you can delete them all in one go.

Answer 1

[Jan]

Perhaps S is your handles struct? Then:

function deleting_plots(source, eventdata)
S = guidata(source);
if ishghanlde(S.hDFplot1)
   delete (S.hDFplot1);
   delete (S.hDFplot2);
end
end

[Jeremy]

Thanks, but that doesn't seem to be working. I get the following two errors. I appreciate the help.

Not enough input arguments.

Error in DFtab/deleting_plots (line 113) S = guidata(source);

[Adam]

You need to give more information. As much relevant information as possible. How the function is called or where it is linked up to as a callback is clearly fundamental information. How are we supposed to guess what S is? In your original code clearly S does not exist in the function workspace.