Hello, i keep getting error of: "Brace indexing is not supported for variables of this type." thanks for the help

function varargout = smooth(varargin)
% SMOOTH MATLAB code for smooth.fig
%      SMOOTH, by itself, creates a new SMOOTH or raises the existing
%      singleton*.
%
%      H = SMOOTH returns the handle to a new SMOOTH or the handle to
%      the existing singleton*.
%
%      SMOOTH('CALLBACK',hObject,eventData,handles,...) calls the local
%      function named CALLBACK in SMOOTH.M with the given input arguments.
%
%      SMOOTH('Property','Value',...) creates a new SMOOTH or raises the
%      existing singleton*.  Starting from the left, property value pairs are
%      applied to the GUI before smooth_OpeningFcn gets called.  An
%      unrecognized property name or invalid value makes property application
%      stop.  All inputs are passed to smooth_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 smooth

% Last Modified by GUIDE v2.5 21-Apr-2020 09:53:57

% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @smooth_OpeningFcn, ...
                   'gui_OutputFcn',  @smooth_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 smooth is made visible.
function smooth_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 smooth (see VARARGIN)

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

% add our own data fields
handles.minFreq = 1;
handles.maxFreq = 10;
handles.amp = 8;
handles.freq = 2.5;
handles.t = 0:0.001:1;
handles.x = handles.amp * sin(2*pi*handles.freq*handles.t);
handles.noise = randn(1,length(handles.t));
handles.radiobutton3 = sin(2*pi*60*handles.t);
handles.window = NaN;
handles.windowIndex = 6;
handles.addRandom = true;
handles.addInterference = false;
handles.plotOriginal = false;
handles.plotNoisy = true;
handles.plotSmoothed = true;

set(handles.amplEdit,'String',num2str(handles.amp));
fs = (handles.freq - handles.minFreq) / (handles.maxFreq - handles.minFreq);
set(handles.freqSlider,'Value',fs);
set(handles.originalBox,'value',handles.plotOriginal);
set(handles.noisyBox,'value',handles.plotNoisy);
set(handles.smoothedBox,'value',handles.plotSmoothed);
set(handles.windowMenu,'Value',handles.windowIndex);
str = get(handles.windowMenu, 'String');
handles.window = str2double(str{handles.windowIndex});
set(handles.radiobutton2,'Value',1);
plotit(handles);

% Update handles structure
guidata(hObject, handles);

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


% --- Outputs from this function are returned to the command line.
function varargout = smooth_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 slider movement.
function freqSlider_Callback(hObject, eventdata, handles)
% hObject    handle to freqSlider (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,'Value') returns position of slider
%        get(hObject,'Min') and get(hObject,'Max') to determine range of slider
fs = get(handles.freqSlider,'Value');
handles.freq = handles.minFreq + fs * (handles.maxFreq - handles.minFreq);
handles.x = handles.amp * sin(2*pi*handles.freq*handles.t);
plot(handles.axes,handles.t,handles.x);
set(handles.axes,'XMinorTick','on');
grid on

% Update handles structure
guidata(hObject, handles);


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

% Hint: slider controls usually have a light gray background.
if isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor',[.9 .9 .9]);
end


function amplEdit_Callback(hObject, eventdata, handles)
% hObject    handle to amplEdit (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 amplEdit as text
%        str2double(get(hObject,'String')) returns contents of amplEdit as a double
amp = str2double(get(hObject,'String'));
if isnan(amp) || ~isreal(amp)
    % isdouble returns NaN for non-numbers and f1 cannot be complex
    % Disable the Plot button and change its string to say why
    set(hObject,'String',num2str(handles.amp));
else
    if abs(amp) > 100
        amp = 100;
        set(hObject,'String',num2str(amp));
    end
    handles.amp = amp;
    handles.x = handles.amp * sin(2*pi*handles.freq*handles.t);
    plot(handles.axes,handles.t,handles.x);
    set(handles.axes,'XMinorTick','on');
    grid on
    guidata(hObject, handles);
end


% --- Executes during object creation, after setting all properties.
function amplEdit_CreateFcn(hObject, eventdata, handles)
% hObject    handle to amplEdit (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 selection change in windowMenu.
function windowMenu_Callback(hObject, eventdata, handles)
% hObject    handle to windowMenu (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hints: contents = cellstr(get(hObject,'String')) returns windowMenu contents as cell array
%        contents{get(hObject,'Value')} returns selected item from windowMenu
% Menu
sel = get(hObject,'String');
handles.window = str2double(sel{get(hObject,'Value')});
plotit(handles);
guidata(hObject, handles);


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

% Hint: listbox 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


function signalControl_SelectionChangeFcn(hObject,eventdata,handles)
switch get(eventdata.NewValue,'Tag') 
    % Get Tag of selected object.
    case 'radiobutton1'
        handles.addRandom = false;
        handles.addInterference = false;
    case 'radiobutton2'
        handles.addRandom = true;
        handles.addInterference = false;
    case 'radiobutton3'
        handles.addRandom = false;
        handles.addInterference = true;
    case 'radiobutton4'
        handles.addRandom = true;
        handles.addInterference = true;
end
plotit(handles);
guidata(hObject, handles);


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

% Hint: get(hObject,'Value') returns toggle state of originalBox
handles.plotOriginal = get(hObject,'value');
plotit(handles);
guidata(hObject, handles);


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

% Hint: get(hObject,'Value') returns toggle state of noisyBox
handles.plotOriginal = get(hObject,'value');
plotit(handles);
guidata(hObject, handles);


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

% Hint: get(hObject,'Value') returns toggle state of smoothedBox
handles.plotOriginal = get(hObject,'value');
plotit(handles);
guidata(hObject, handles);

[Rik]

I don't see at a glance where the error would occur. Could you show the complete error message and remove all the irrelevant callbacks from the code you show?

Can you confirm the error doesn't occur in the plotit function?

[arthur doroshev]

function plotit(handles)
noisy = handles.x;
if handles.addRandom
    noisy = noisy + handles.noise;
end
if handles.addInterference
    noisy = noisy + handles.interference;
end
smoothed = smoothit(noisy,handles.window);
if ~(handles.plotOriginal || handles.plotNoisy || handles.plotSmoothed)
    cla(handles.axes,'reset');
else
    if handles.plotOriginal
        plot(handles.axes,handles.t,handles.x,'k');
        hold(handles.axes,'on');
    end
    if handles.plotNoisy
        plot(handles.axes,handles.t, noisy,'r');
        hold(handles.axes,'on');
    end
    if handles.plotSmoothed
        plot(handles.axes,handles.t,smoothed,'b');
    end
    set(handles.axes,'XMinorTick','on');
    grid on
    hold(handles.axes,'off');
end

[arthur doroshev]

and the error is:

Brace indexing is not supported for variables of this type.

Error in smooth>smooth_OpeningFcn (line 83)

handles.window = str2double(str{handles.windowIndex});

Error in gui_mainfcn (line 220)

feval(gui_State.gui_OpeningFcn, gui_hFigure, [], guidata(gui_hFigure), varargin{:});

Error in smooth (line 42)

gui_mainfcn(gui_State, varargin{:});

[arthur doroshev]

the inside function are ok it is just row # 83

[Image Analyst]

Remove the semicolon and add whos to your oepning function:

str = handles.windowMenu.String
whos str

Set a breakpoint right after that whos and tell me what you see in the command window. Also, what values did you load into the windowMenu control's string property in GUIDE?

[arthur doroshev]

str =

'1'

Name Size Bytes Class Attributes

str 1x1 2 char

Answer 1

[Image Analyst]

So there is only one string in there and hence it's not a cell array but a simple character array. You'll need to put str into a cell first

str = {handles.windowMenu.String};

and then you'll need to make sure that handles.windowIndex is not more than 1 or the current length of str

if handles.windowIndex > length(str)
    warningMessage = sprintf('Error: you are trying to access string #%d in str, but str has only %s strings in it!',...
        handles.windowIndex, length(str));
    uiwait(errordlg(warningMessage));
    handles.window = str{1};
    handles.windowIndex = length(str); % Optional - if you want to fix the value or not.
else
    handles.window = str2double(str{handles.windowIndex});
end