Cell contents reference from a non-cell array object error

I have a code for selecting regions of interest on an image, create a mask and then apply this mask to the matrices in a cell array. The problem that is occurring is that Matlab says the cell contents reference a non-cell array object.

Cell contents reference from a non-cell array object.

Error in hopefully_the_last_window>pushbutton3_Callback (line 191)
    Y = X{i}.*mask;

Error in gui_mainfcn (line 96)
        feval(varargin{:});

Error in hopefully_the_last_window (line 42)
    gui_mainfcn(gui_State, varargin{:});

Error in
@(hObject,eventdata)hopefully_the_last_window('pushbutton3_Callback',hObject,eventdata,guidata(hObject))

Error while evaluating uicontrol Callback

I read on another answer on Mathworks that changing the {} brackets in my code to standard brackets () would fix this error ( changing Y = X{i}.*mask to Y = X(i).*mask). When I did this Matlab simply froze and stopped responding. Is this fix a decent solution to the error with some tweaks to stop matlab freezing or is there another possible cause of the error than the bracket?

Answer 1

[Jan]

Look at the code:

X = handles.finishCell;
mask = labeledImage;
for i = 1 : numel(X)
    Y = X{i}.*mask;
end

We cannot know, what the contents of "handles.finishCell" is. The error message tells clearly, that it is not a cell array. Then simply using round parenthesis is pure guessing. You have to find out, what the contents of this variable is. Do not apply a solution, which was posted for perhaps a completely different problem.

Note that Y is overwritten in each iteration. Perhaps you want Y{i} also. Then some lines later:

handles.X = Y{i};

Are you sure, that you want the last element of Y only?