Issue with 'Conversion to cell from double is not possible' error.

Using a GUI to upload data from a user defined location and analyze it. I've come across an issue with the data acquisition. Is there some sort of data type or format conversion that I need to do?

Code:

% --- Executes on button press in readdir.
function readdir_Callback(hObject, eventdata, handles)
% hObject    handle to readdir (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Use user defined directory
directory=get(handles.textbox1,'String');
files=dir(directory);
% Build vector of file names in directory
    % Files is a struct, 14 different values in field 'name'
    % Last 11 values (4-14) are actual data files
    % 'files(1).name = '.'
    % 'files(2).name = '..'
    % 'files(3).name = DetectionCodes.xlsx 
        % Is used later on and isn't needed for this pushbutton  
names = [files(4).name;files(5).name;files(6).name;files(7).name;files(8).name;files(9).name;files(10).name;files(11).name;files(12).name;files(13).name;files(14).name;]

% Loop for uploading data
for i=1:length(names);
    s=names(i,:);
    s=strcat('\',s);
    L=strcat(directory, s)
    [num, txt, all] = xlsread(L); 
        % Excel file must not have first line titles
    [m,n]=size(txt);
for j=1:n;
    % Deletes space in the string
    txt{j}=regexprep(txt{j},'','NaN');
    % Assign columns of data to name in column label
    txt(j)=num(:,j);
    % Create a global variable for all of the data
    handles.data(i).txt(j)=num(:,j);
guidata(hObject,handles);

end
guidata(hObject,handles)

end
display('Data reading is complete.')
display(handles);

Error:

??? Conversion to cell from double is not
possible.

Error in ==> GUI_Patchline>readdir_Callback
at 127
    txt(j)=num(:,j);

Error in ==> gui_mainfcn at 96
        feval(varargin{:});

Error in ==> GUI_Patchline at 41
    gui_mainfcn(gui_State, varargin{:});

Error in ==>
@(hObject,eventdata)GUI_Patchline('readdir_Callback',hObject,eventdata,guidata(hObject))

??? Error while evaluating uicontrol Callback

Answer 1

[Jan]

It looks strange that you assign the content of the cell txt{j} at first and in the next line the cell txt(j) (round parentheses) is assigned. But the error message means, that txt(j) is a cell and you try to assigne the numerical vector num(:,j). So perhaps you want curly braces in this line also.

By the way: This is nicer:

names = {files(4:14).name};

Prefer fullfile to concatenate folder and file names, because the hard coded appending of backslashes is platform dependent and prone to bugs.

Updating the handles struct in each iteration is a waste of time. Better call guidata once after the loops.

[Zeke Merchant]

You were a huge help, thank you!

Answer 2

[Areej Al-Saffar]

Hi When i run the LTEDownlinkExample using MATLAB2013 this error appear to me (in LTEDownlinkExample/Spectrum/Spectrum Analyzer.....Conversion to cell from double is not possible.)please help me, thanx

[Image Analyst]

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