App Designer Edit Numeric how to express test

I need to create a graph in App Designer, but the graph is too large and I need to shorten it, I try to do this using Edit Numeric, but an error occurs Index exceeds the number of array elements (0)

function depthButtonMenuSelected(app, event)
            title(app.UIAxes, 'Obj3010')
            xlabel(app.UIAxes, 'zone')
            ylabel(app.UIAxes, 'Ob')
            app.Obj=app.Obj(app.a:app.b); % Index exceeds the number of array elements (0).
            plot(app.UIAxes,app.d,'LineWidth',5);
end
%
function aEditFieldValueChanged(app, event)
        app.a = app.aEditField.Value;          
end
function bEditFieldValueChanged(app, event)
        app.b = app.bEditField.Value;          
end

Answer 1

[Mehmed Saad]

it is because app.Obj is empty. it has no value.

First check what is app.Obj? maybe what you are trying to do is

app.d=app.d(app.a:app.b);

[Lev Mihailov]

You were right, and I have one question, is it possible, when you click the button, the values ​​themselves were edited in Edit Numeric?

function MinAPushed(app, event)
        app.a=1;
end
%
function MaxAPushed(app, event)
        app.b=max(app.d);
end

[Mehmed Saad]

see the attached app button callback

app.EditField_name.Value = app.a;

Also it is not necessary that max(app.d) is less than app.d length or is interger

For example

app.d = [1 2 6 4];

Now

app.b=max(app.d); % app.b is max value of app.d and not max value index

so app.b is 6 and now your code

app.d(app.a:app.b)

wil try to access app.d from 1st index to 6th index which doesnot exist

to get max value index see help of max