How to display all the while loop at static text? (matlab GUI)

How to display the while loop output at static text on GUI?

I want this output below

i=5

i=4

i=3

i=2

i=1

i=0

code

i = 5;

while i > 0 

      txt=fprintf('i = %d\n', i);

      i = i - 1;

      set(handles.ans, 'String',txt);

end

This code not working

Answer 1

[Jos]

Hi Abraham,

try this (assuming you added a push button to start the program and 'ans' is your static text box). Since txt will be a growing variable the size of each line has to be the same length, so if you want to start at i=10 change num2str(i,'%d') to num2str(i,'%02d') although this will result in output

i=10

i=09

i=08

etc

% --- Executes on button press in pushbutton1.
function pushbutton1_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
i = 5;
txt = [];
while i > 0 
      txt=[txt;'i = ' num2str(i,'%d')];
      i = i - 1;
      set(handles.ans, 'String',txt);
end

Answer 2

[Geoff Hayes]

Abraham - if you step through this code (which is presumably in some sort of callback for one of your GUI controls) you would observe that the output from fprintf, txt, is a double and not a string (the carriage return/line break in the string is also problematic for single line text fields). Instead of the above, try the following with sprintf

 for k=5:-1:1 
      txt=sprintf('k = %d', k);
      set(handles.edit1, 'String',txt);
      pause(1.0);
 end

Note the use of the for loop and how we can decrement the counter. The pause for one second allows us to actually see the change to the edit control at each iteration of the loop.