MATLAB: ‘Undefined function or variable ‘ error but variable is defined in function working in GUI

functionguiMATLABorundefinedvariable

So I have another problem with GUI. Like I said, I've perfectly working code but when I tried to get it into GUI I get this error:

Undefined function or variable 'h'.
Error in untitled>FILT_IMG_Callback (line 105)
    f=(h-1)/2;    % padding value for window: f=1; f=2; f=3; f=4; f=5;


Error in gui_mainfcn (line 95)
        feval(varargin{:});
Error in untitled (line 42)
    gui_mainfcn(gui_State, varargin{:});

I don't understand why I'm getting this error because variable is already defined. Here's code:

function FILT_IMG_Callback(hObject, eventdata, handles)
% hObject    handle to FILT_IMG (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
X = getappdata(0,'X');
A = rgb2gray (X);
X = A;
%setappdata(0,'filename',X);
%axes(handles.axes1);
%imshow(X);
if nargin < 2
    h=3;    % local search window size: h=3; h=5; h=7; h=9; h=11;
    f=1;    % padding value for window: f=1; f=2; f=3; f=4; f=5;
else
    f=(h-1)/2;    % padding value for window: f=1; f=2; f=3; f=4; f=5;
end
F = zeros(h*h,1);
Y  = zeros(size(X));
X = double(padarray(X,[f f],'symmetric'));
[m n ~] = size(X); 
%etc

Any ideas?

Best Answer

if nargin < 2
    h=3;    % local search window size: h=3; h=5; h=7; h=9; h=11;
    f=1;    % padding value for window: f=1; f=2; f=3; f=4; f=5;

else
    f=(h-1)/2;    % padding value for window: f=1; f=2; f=3; f=4; f=5;
end

if nargin>=2, then h is not defined.

Related Solutions

MATLAB: Adding stop button to stop the data streaming from comport to GUI builder

OK, where to start.

Buttons... You create buttons from code with the uicontrol function. A pushbutton could be made like this:

buttonHandle = uicontrol(f,'Style','Pushbutton','Position',[x,y,w,h],'Callback',{@ButtonCBF,var1});

This will create a button as a child object in figure f at the designated position in f with a callback function "ButtonCBF". Any time the button is pushed, it will call ButtonCBF as follows:

ButtonCBF(hObject,event,var1)

Where hObject is the button handle, event is empty, and your specified variable var1 is passed as the next parameter. In the callback, you can specify what you want the button to do in terms of code.

Updating the GUI:

I would strongly suggest not using a while loop. Use timers or a listening function to check the COM for data and update the GUI window. First thing, the pause function is blocking meaning you can't do anything else while paused. Second, pause is highly inaccurate at small time values and can't really time anything less than 0.01 seconds. Even at 0.01, I often get close to 0.02 seconds as the time actually elapsed during the pause.

Serial communication:

I would make a listener function for your serial connection that automatically receives and stores the data sent by the device. In fact, you should probably have the listener function update your GUI for you as well. You'll either need a global variable for it to check whether or not its supposed to update the GUI or instead of a Start and Stop pushbutton use a checkbox and check its value in the listener function.

You could use something like this:

cb = uicontrol(f,'Style','Checkbox','Position',[x,y,w,h],'Tag','MyCB');
function myListener(hObject,~)
input = [];
while hObject.BytesAvailable > 0
    temp = fscanf(hObject);
    input = [input,temp];
end
if get(findall(0,'Tag','MyCB'),'Value') == 1
    % Update the GUI
end

Of course, you'll need to make a closing function for your figure so that it deletes the com object when you close the window or you'll have to do it manually.

When programming GUIs, you should design them so that most of the functionality is handled by listeners and callbacks. The function that creates the GUI should return once the figure is created and all uicontrols are setup.

MATLAB: This what is error coming to me… Undefined variable “retfinalll” or class “retfinalll.m”. Error in gui1>pushbutton3_Callback (line 94) run(retfinalll.m); Error in gui_mainfcn (line 95) feval(varargin{:}); Error in gui1 (line 42) gui_

The RUN function accepts a char vector containing the name of the script to execute. You're not passing it a char vector containing a name.
Your script file includes at least two problematic commands that I recommend you remove.

CLEAR, which will clear the variables in the workspace of the callback function in which it's executed, including the GUI's handles structure, which would break execution of that callback function. This would be a bigger problem but for the third command you execute.
CLOSE ALL, which will close all open figures, including your GUI.

So unless you indicated to the user that pushbutton3 will close the GUI, they may be confused by its behavior. I would eliminate those two commands as well as the CLC command (your code doesn't need to clear the Command Window, so why do it?)

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