main function of GUI with a sub function, I want to get the output of sub function as input

In my gui function there is a sub function (fcn1) that I want to get its output (y) for a push button callback (fcn2) in the main function, but I cannot get the output of sub function: I appreciate if anyone can help;

function [V]=Problem

sz=get(0,'ScreenSize');
figure('numbertitle','off','menubar','none','position',[sz(3)/3 sz(4)/4 sz(3)/2.8 sz(4)/1.5]);

uicontrol('style','text','string','Select equation','position',
[20 450 180 35],'fontsize',12,'backgroundcolor','g','horizontalalignment','left');
V.al=uicontrol('style','popup','string',{'choice A','Choice B'},...
'position',[220 450 150 35],'fontsize',12,'backgroundcolor','w','horizontalalignment','left');
     set(V.al,'callback',{@fcn1,V}); 

      function [V]=fcn1(varargin)
          V=varargin{3};
          if get(V.al,'value')==1
              helpdlg('3/x+2*x^2+1','Ref. Eqaution');
          else
              y=inputdlg('Vs=','User Equation',[1,33],{'sind(x)*x^2+1'});
          end
      end

uicontrol('style','pushbutton','string','ok','backgroundcolor','y','position',[200 20 30 30],'callback','[r]=fcn2(y);close');

end

Answer 1

[Walter Roberson]

function [V] = Problem

    sz = get(0, 'ScreenSize');
    fig = figure('numbertitle', 'off', 'menubar', 'none', 'position', [sz(3)/3 sz(4)/4 sz(3)/2.8 sz(4)/1.5], 'tag', 'Problem_fig');

    uicontrol('Parent', fig, 'style', 'text', 'string', 'Select equation', 'position', 
    [20 450 180 35], 'fontsize', 12, 'backgroundcolor', 'g', 'horizontalalignment', 'left');

    V.al = uicontrol('Parent', fig, 'style', 'popup', 'string', {'choice A','Choice B'}, ...
    'position', [220 450 150 35], 'fontsize', 12, 'backgroundcolor', 'w', 'horizontalalignment', 'left', ...
    'tag', 'V_a1');
    set(V.al, 'callback', {@fcn1, V}, 'UserData', '');

    uic3 = uicontrol('Parent', fig, 'style', 'pushbutton', 'string', 'ok', 'backgroundcolor', 'y', 'position', [200 20 30 30], 'callback', 'V_a1 = findobj(0, 'tag', ''V_a1''); y = get(V_a1, ''UserData''); [r] = fcn2(y); close(ancestor(V_a1, ''figure''))', 'enable', 'off');

    function fcn1(varargin)
      V = varargin{3};
      if get(V.al, 'value') ==1
        helpdlg('3/x+2*x^2+1','Ref. Equation');
      else
        y = inputdlg('Vs =', 'User Equation', [1,33], {'sind(x)*x^2+1'});
        set(V.a1, 'UserData', y);
        set(uic3, 'enable', 'on')
      end
    end

end

[omid]

Dear MR Roberson

I don't know how to thank you. It was great solution.

God help you

[Walter Roberson]

It would be better to make the code of the uic3 callback into a separate function, though. Programming callbacks as strings is ugly and error prone.

[omid]

Sure I will do it. Again thanks for the great help

Answer 2

[Image Analyst]

fcn needs to return the variable, y. Otherwise, y is just a local variable used internal to the function and vanishes once the function has finished running.

function [y, V] = fcn1(varargin)

If you need y in functions other than the function that called fcn1(), then see the FAQ: http://matlab.wikia.com/wiki/FAQ#How_can_I_share_data_between_callback_functions_in_my_GUI.28s.29.3F

[Walter Roberson]

Note that you have

set(V.al,'callback',{@fcn1,V});

When you set something as a callback, it is evaluated at the base workspace, in an environment that expects no outputs, like

feval(varargin{1}, hObject, event, varargin{2:end});

Therefore it cannot usefully return any value. Returning y will not help here. You have to push the y value out to a place that the other function knows to look.

[omid]

Thanks to IA I have done it already but it doesn't give me output y