How to deal with the string in GUI for multiple .m files ?

Hello, I'd like to display the 'i' circulating in 'for' loop.

The main structure is like this :

After click the run button on GUI(in Main_GUI), 'STEP1.m' and 'STEP2.m' are implemented.

(I used the 'evalin' function to execute the .m file, for example, evalin('base', 'STEP1_COPY_LE_RESULT_mod'); )

'STEP1.m' is to make the excels, and 'STEP2' is to do simulation. 'STEP2.m' has for loop.

% 'STEP2.m' file 
for i = 1 : case_num
    Input_num = i;
    sim(slx, Input_num)

      % I'd like to display the 'i' number in GUI.
      % set(handles.gui_string, 'String', num2str(i));
  end

but I don't know how can I do this. I used guidata, getappdata, setappdata, and so on...

Please help me. I need your help. Thanks in advance.

Answer 1

[Walter Roberson]

       set(handles.gui_string, 'String', num2str(i));
       drawnow();

[octopus_love]

oh, I click the 'accept answer' button. It's my mistake. but it doesn't work.

command window tells that "'handles.gui_string' is not define".

I don't know..

[Walter Roberson]

Before this section, use

handles = guidata(gcf);