MATLAB: How can i check if the axes handles exist or not

axescallbackfind handlesguihandlespushbutton

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?

Best Answer

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.

Related Solutions

MATLAB: How to check if handle is to a deleted axes

A couple of choices.

h = plot(1:10);
delete(h)
isvalid(h)
isgraphics(h)

Either of those will return false for a deleted handle. They differ on what they return true for. The first will return true for any valid handle. The second one will return true only for graphics objects. It also supports an argument to ask if it is a particular type of graphics object.

MATLAB: Check if handle to axes exists at all [R2017b]

The code is not meaningful. You can always know, if the axes has been created before or not. Therefore it is not clear, what you are exactly asking for. Maybe this helps:

f = gobjects(0);
h = gobjects(0);
% Then a magic section, which does not let you know if the axes is
% existing or not:
if rand > 0.5
  f = figure;
  h = axes;  % 

end
...
if ~isgraphics(h)   % Better than ishandle
  f = figure;
  h = axes;  % 
end
line(x, 1:10, rand(1, 10))

So define the variable holding the handle as an empty graphics object at first. The empty matrix would work also. Then you can check if the variable contains a valid graphics object.

Best Answer

Related Solutions

MATLAB: How to check if handle is to a deleted axes

MATLAB: Check if handle to axes exists at all [R2017b]

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