The stop button doesn't terminate the process when pressed.

Hello all, below is my code of GUI. It was working fine but as soon as I added a slider to colloect the value of rate of data acquisition the orocess doesn;t terminate when stop button is pressed. The code is below: (Note the dataGen2 just returns a random number);

function varargout = testgui2(varargin)
% TESTGUI2 MATLAB code for testgui2.fig
%      TESTGUI2, by itself, creates a new TESTGUI2 or raises the existing
%      singleton*.
%
%      H = TESTGUI2 returns the handle to a new TESTGUI2 or the handle to
%      the existing singleton*.
%
%      TESTGUI2('CALLBACK',hObject,eventData,handles,...) calls the local
%      function named CALLBACK in TESTGUI2.M with the given input arguments.
%
%      TESTGUI2('Property','Value',...) creates a new TESTGUI2 or raises the
%      existing singleton*.  Starting from the left, property value pairs are
%      applied to the GUI before testgui2_OpeningFcn gets called.  An
%      unrecognized property name or invalid value makes property application
%      stop.  All inputs are passed to testgui2_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 testgui2

% Last Modified by GUIDE v2.5 11-Apr-2023 09:41:56

% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
    'gui_Singleton',  gui_Singleton, ...
    'gui_OpeningFcn', @testgui2_OpeningFcn, ...
    'gui_OutputFcn',  @testgui2_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 testgui2 is made visible.
function testgui2_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 testgui2 (see VARARGIN)

% Choose default command line output for testgui2
handles.output = hObject;



handles.tdata = [];
handles.rate = get(handles.RateSlider,'value');
handles.stopval=0;
% Update handles structure
guidata(hObject, handles);

% UIWAIT makes testgui2 wait for user response (see UIRESUME)
% uiwait(handles.figure1);


% --- Outputs from this function are returned to the command line.
function varargout = testgui2_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 start.
function start_Callback(hObject, eventdata, handles)
% hObject    handle to start (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

i=1;
status1 = get(handles.start,'value');
status2 = get(handles.stop,'value');
while(status1 && ~status2)
    rate3 = handles.rate;
    value(i) = dataGen2;
    time(i) = (i-1)/rate3;
    handles.tdata = [time;value];
    pause(1/rate3);
    stem(handles.axes1,handles.tdata(1,:),handles.tdata(2,:));
    i=i+1;
    status2 = handles.stopval;
    
    guidata(hObject,handles);
    
    
end





% --- Executes on button press in stop.
function stop_Callback(hObject, eventdata, handles)
% hObject    handle to stop (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
handles.stopval=1;
guidata(hObject,handles);


% --- Executes on button press in save.
function save_Callback(hObject, eventdata, handles)
% hObject    handle to save (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
data = handles.tdata';
headers = {'time', 'value'};

output = [headers; num2cell(data)];
writetable(cell2table(output), 'data.txt', 'Delimiter', 'tab', 'WriteVariableNames', false);




function rate_Callback(hObject, eventdata, handles)
% hObject    handle to rate (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 rate as text
%        str2double(get(hObject,'String')) returns contents of rate as a double


% --- Executes during object creation, after setting all properties.
function rate_CreateFcn(hObject, eventdata, handles)
% hObject    handle to rate (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 slider movement.
function RateSlider_Callback(hObject, eventdata, handles)
% hObject    handle to RateSlider (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
sliderMin = get(hObject, 'Min');
sliderMax = get(hObject, 'Max');
% Get the current value of the slider
sliderValue = get(hObject, 'Value');
% Scale the slider value to the appropriate range
rate2 = sliderMin + (sliderValue*(sliderMax - sliderMin));
handles.rate = rate2;
guidata(hObject,handles);

% Update the rate display



% --- Executes during object creation, after setting all properties.
function RateSlider_CreateFcn(hObject, eventdata, handles)
% hObject    handle to RateSlider (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

Answer 1

[Adam Danz]

Looks like

 status2 = handles.stopval

should be

 status2 = handles.stopval.Value;

[Rik]

Just to be clear: this is true both in the while loop, and in the callback.

You should make sure to set the stop button back when you start the function, otherwise you can only use the stop once.