MATLAB: Set the Variable ‘Global’ in GUI

guivariables

I'm working with MATLAB GUI.

When I'm trying to access the variable which was defined with the push button, it is not defined in the pop up menu. The variables; it should be set 'global', so it is defined in the whole program. And I can use it in any callback.

Do you guys have any idea of how to make the variables 'global'?

Your help will be much appreciated.

Thank you.

Best Answer

If you want to use it in any callback use guidata

handles.yourvar=yourvar
guidata(hObject,handles)

To use the variable yourvar

yourvar=handles.yourvar

Related Solutions

MATLAB: SelectionChangeFcn not receiving handles

set(handles.uipanel1,'SelectionChangeFcn',...{@uipanel1_SelectionChangeFcn,handles});

MATLAB: ‘Global’ Variables in a guide GUI

Using global variables is a bad idea in general. They impede the debugging and the increase the level of complexity. You find many corresponding discussions here in the forum, but this problem concens other programming languages also. Ask an internet search engine for details.

But of course it is possible:

Define the global variables in each function, which needs to access them:

function y = myComputations(x)
global gParameter
y = gParameter * x;
end

This is done inside the callbacks also:

function Button1_Callback(hObject, EventData, handles)
global gParameter
gParameter = 1;
end
function Button2_Callback(hObject, EventData, handles)
global gParameter
gParameter = 2;
end

If you need the variable in so base workspace, define them as global here also.

If you need the variable in the base workspace only, e.g. as input for a Simulink method, do not define it as global but using:

function Button1_Callback(hObject, EventData, handles)
assignin('base', 'gParameter' 1);
end

This is not as evil as global variables, but you cannot trace the source of the current value of these variables reliably also.

If 'global' means, that the variable needs to be shared between callbacks of a figure only, use either set/getappdata, guidata or the 'UserData' of the corrsponding GUI element. This allows e.g. to run two instances of the same GUI without conflicts. Please ask, if you need further explanations for this.

Best Answer

Related Solutions

MATLAB: SelectionChangeFcn not receiving handles

MATLAB: ‘Global’ Variables in a guide GUI

Related Question