how can i check if the axes handles exist or not ?

I have GUI which has several pushbuttons. The pushbutton create handles to axes. I want to check if the specific handle or set of handles exist and then write necessary code whether to delete the handle or not ? how can I do it?

Answer 1

[Jan]

See https://www.mathworks.com/help/matlab/graphics_transition/graphics-handles-are-now-objects-not-doubles.html#budq3t3

if isgraphics(handles.axes1)

In Matlab versions older than R2014b:

if ishghandle(handles.axes1)

I'd prefer ishghandle, because isgraphics accepts integer handles also, which is less reliable in my opinion.

[VBBV]

ok, I used the following code to check handle f1 and to delete it

if ishandle(handle,'f1') 
    delete(handles.f1)
    ...
    ...
    % new plot
    plot something
end

but it doesn't seem to work. although it doesnt show any error, it does not plot new one ... why does it happen

[Image Analyst]

Where did you expect to plot it? Not in f1 since you deleted that axes. So it would plot in whatever now became the current axes. If there was no other axes left, it would have created one.

You can pass the axes handle into plot() you know.

[Jan]

It is not clear, what you expect ishandle(handle,'f1') to do. What is "handle"? Why do you expect ishandle to accept a second input argument called 'f1'? See: doc ishandle to see, that you do not use this command correctly. If it does not show an error, maybe you do not run the code at all?

Did you read my answer?

if isgraphics(handles.f1)

seems to be better.

[VBBV]

@Jan, yeah, ishandle() function has only ONE input argument and also isgraphics() works better than ishandle() ... it works fine now. thanks for the solution.