Equation is working but the output is not displaying

I have created a program to automatically convert letters into morse code, but for some reason the output is not being saved, can someone please help me on this? thanks

function varargout = FOPfinal(varargin)
% FOPFINAL MATLAB code for FOPfinal.fig
%      FOPFINAL, by itself, creates a new FOPFINAL or raises the existing
%      singleton*.
%
%      H = FOPFINAL returns the handle to a new FOPFINAL or the handle to
%      the existing singleton*.
%
%      FOPFINAL('CALLBACK',hObject,eventData,handles,...) calls the local
%      function named CALLBACK in FOPFINAL.M with the given input arguments.
%
%      FOPFINAL('Property','Value',...) creates a new FOPFINAL or raises the
%      existing singleton*.  Starting from the left, property value pairs are
%      applied to the GUI before FOPfinal_OpeningFcn gets called.  An
%      unrecognized property name or invalid value makes property application
%      stop.  All inputs are passed to FOPfinal_OpeningFcn via varargin.
%
%      *See GUI Options on GUIDE's Tools menu.  Choose "GUI allows only one
%      instance to run (singleton)".
%
% See also: GUIDE, GUIDATA, GUIHANDLES

% Edit the above text to modify the response to help FOPfinal

% Last Modified by GUIDE v2.5 11-Apr-2022 19:19:26

% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @FOPfinal_OpeningFcn, ...
                   'gui_OutputFcn',  @FOPfinal_OutputFcn, ...
                   'gui_LayoutFcn',  [] , ...
                   'gui_Callback',   []);
if nargin && ischar(varargin{1})
    gui_State.gui_Callback = str2func(varargin{1});
end

if nargout
    [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});
else
    gui_mainfcn(gui_State, varargin{:});
end
% End initialization code - DO NOT EDIT


% --- Executes just before FOPfinal is made visible.
function FOPfinal_OpeningFcn(hObject, eventdata, handles, varargin)
% This function has no output args, see OutputFcn.
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
% varargin   command line arguments to FOPfinal (see VARARGIN)

% Choose default command line output for FOPfinal
handles.output = hObject;

% Update handles structure
guidata(hObject, handles);

% UIWAIT makes FOPfinal wait for user response (see UIRESUME)
% uiwait(handles.figure1);


% --- Outputs from this function are returned to the command line.
function varargout = FOPfinal_OutputFcn(hObject, eventdata, handles) 
% varargout  cell array for returning output args (see VARARGOUT);
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Get default command line output from handles structure
varargout{1} = handles.output;


% --- Executes on button press in pushbutton1.
function pushbutton1_Callback(hObject, eventdata, handles)

errordlg ('Covert any text into morse code with this app! To decode morse code back into text, press the SWITCH button','Help me')
% 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)



function text_input_Callback(hObject, eventdata, handles)
% hObject    handle to text_input (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of text_input as text
%        str2double(get(hObject,'String')) returns contents of text_input as a double
text_input=get(hObject,'string');

handles.text_input=text_input;
guidata(hObject,handles);

% --- Executes during object creation, after setting all properties.
function text_input_CreateFcn(hObject, eventdata, handles)
% hObject    handle to text_input (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.
%       See ISPC and COMPUTER.
if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor','white');
end


% --- Executes on button press in pushbutton2.
function pushbutton2_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton2 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
userinput = handles.text_input;
output_string = '';
userinput = upper(userinput);
userinput = strjoin(strsplit(userinput));
morsecode={'.----','..---','...--','....-','.....','-....','--...','---..','----.','-----','.-','-...','-.-.','-..','.','..-.','--.','....','..','.---','-.-','.-..','--','-.','---','.--.','--.-','.-.','...','-','..-','...-','.--','-..-','-.--','--..','/'};
NumberOrLetter={'1','2','3','4','5','6','7','8','9','0','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z',' '};
for i=1:length(userinput);
    [~, index] = ismember(userinput(i), NumberOrLetter);
    if index > 0
        output_string = [output_string ' ' morsecode(index)];
    end     
end
fprintf('\n');
set(handles.morse, 'String' , output_string);


% --- Executes on button press in pushbutton3.
function pushbutton3_Callback(hObject, eventdata, handles)

% hObject    handle to pushbutton3 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

[Voss]

@Nicholas Mun If you have an object stored in your handles structure called "text_input", e.g., an edit box where the user enters the string to be encoded, then you don't want to be doing this:

function text_input_Callback(hObject, eventdata, handles)
text_input=get(hObject,'string');
handles.text_input=text_input;
guidata(hObject,handles);

because these two lines:

handles.text_input=text_input;
guidata(hObject,handles);

overwite the value of handles.text_input, and set it to be the 'String' of the uicontrol that was previously known as handles.text_input.

So then any part of the code that expects handles.text_input to be an edit box (or whatever type of uicontrol) will have a problem because handles.text_input is now a character vector (or a string or a cell array - but not a uicontrol).

In your code, as it's shown here, that's not a problem because nowhere in the code refers to handles.text_input expecting it to be a uicontrol. However, there is the potential for the opposite problem: parts of the code expect handles.input_text to be a string (or whatever) when it is actually a uicontrol. Consider what happens if pushbutton2_Callback is executed before text_input_Callback is ever executed (i.e., the user clicks pushbutton2 without having entered text into text_input):

function pushbutton2_Callback(hObject, eventdata, handles)
% handles.text_input here is expected to be the string entered by the user,
% but if text_input_Callback has not been executed yet, then it is still the
% uicontrol handles.text_input ...
userinput = handles.text_input;
output_string = '';
userinput = upper(userinput);
% ... so you'll get an error here, trying to strsplit a uicontrol:
userinput = strjoin(strsplit(userinput));

In order to avoid this problem, you can still store the string the user entered, but don't use a name that's used by a uicontrol you might still need to access. For instance, you might call it text_input_by_user:

function text_input_Callback(hObject, eventdata, handles)
text_input=get(hObject,'string');
handles.text_input_by_user=text_input;
guidata(hObject,handles);

and then in pushbutton2_Callback obviously you would refer to that new name:

function pushbutton2_Callback(hObject, eventdata, handles)
userinput = handles.text_input_by_user;

However, you don't need to store it at all; you can always just get it from the uicontrol itself whenever you need it:

function pushbutton2_Callback(hObject, eventdata, handles)
userinput = get(handles.text_input,'String');

and the uicontrol handles.text_input doesn't need to have a Callback in that case.

[Nicholas Mun]

thanks! but when i try to use the third way you suggested (the get() function) i get an error saying that my tag is invalid, here is the exact error

Error using get
Invalid handle

Error in FOPfinal>pushbutton2_Callback (line 117)
userinput = get(handles.text_input);

Error in gui_mainfcn (line 95)
        feval(varargin{:});

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

Error in matlab.graphics.internal.figfile.FigFile/read>@(hObject,eventdata)FOPfinal('pushbutton2_Callback',hObject,eventdata,guidata(hObject))

But in my guide editor the tag text_input does exist for one of the edit boxes, and i dont know why the error occurs. Here is a picture of the inpector of that editbox

[Voss]

This is caused by the very problem I was explaining ... overwriting handles.text_input with something that's not a handle. I would restart the GUI and try it again, after making this change:

function pushbutton2_Callback(hObject, eventdata, handles)
userinput = get(handles.text_input,'String'); % don't forget the 'String'

Answer 1

[Geoff Hayes]

@Nicholas Mun - without knowing exactly what the input string looks like, I think that you need to replace

output_string = [output_string ' ' morsecode(index)];

with

output_string = [output_string ' ' morsecode{index}];

. Since morsecode is a cell array of strings, then we use the {} to index into the array to extract the string. Note that when you use (), a cell is returned instead (which means that the output_string would be cell array.

Note that you should probably remove the line

fprintf('\n');

as I don't think it serves any real purpose.

[Geoff Hayes]

Nicholas' answer moved here

Thanks, the code i have now works

userinput = handles.text_input;
moutput = '';
userinput = upper(userinput);
userinput = strjoin(strsplit(userinput));
morsecode={'.----','..---','...--','....-','.....','-....','--...','---..','----.','-----','.-','-...','-.-.','-..','.','..-.','--.','....','..','.---','-.-','.-..','--','-.','---','.--.','--.-','.-.','...','-','..-','...-','.--','-..-','-.--','--..','/'};
NumberOrLetter={'1','2','3','4','5','6','7','8','9','0','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z',' '};
for i=1:length(userinput);
    [~, index] = ismember(userinput(i), NumberOrLetter);
    if index > 0
        moutput = [moutput morsecode(index)];
    end     
end

set(handles.morse, 'String' , moutput);

but the output in my static text box in the GUI is vertical, all the morse code goes linearly down....may i know how to change that? Here is a picture of the output in the GUI

[Geoff Hayes]

@Nicholas Mun - if you use the MATLAB debugger you can step through the code and see that the array updated with

moutput = [moutput morsecode(index)];

is a cell array rather than a string. I think that you should revert the above to

moutput = [moutput ' ' morsecode{index}];

Note how we use the {} rather than () when indexing into morsecode.

[Nicholas Mun]

works perfectly now thanks!