Error using axes. Invalid object handle.

I created a matlab GUI with togglebutton1 and axes1. I would like to push the button and view the -signal plotted in axes1. Here is my code. I tried to make it as small as I could in order to expose the problem.

function varargout = untitled3(varargin)

% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @untitled3_OpeningFcn, ...
                   'gui_OutputFcn',  @untitled3_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

function untitled3_OpeningFcn(hObject, eventdata, handles, varargin)
handles.output = hObject;
guidata(hObject, handles);

global buttonState
buttonState=1;

global Fs
global T
global recObj
global i
global sig
global r

Fs = 8000;                    %# sampling frequency in Hz
T = 0.03;                        %# length of one interval signal in sec

%# prepare audio recording
recObj = audiorecorder(Fs,8,1);
i=1;
while (buttonState)
    recordblocking(recObj, T);
    sig = getaudiodata(recObj);
    r=xcorr(sig,'coeff'); 
    axes(handles.axes1);
    subplot(3,1,3); 
    plot(r); 
    legend('Autocorrelation'); 
    xlabel('Delay (s)'); 
    ylabel('Correlation coeff.'); 
    drawnow                   %# force MATLAB to flush any queued displays
    i=i+1;

end

function varargout = untitled3_OutputFcn(hObject, eventdata, handles) 
varargout{1} = handles.output;

function togglebutton1_Callback(hObject, eventdata, handles)
isPushed=get(hObject,'Value');
if isPushed
    i=1;
    buttonState=0;
    set (hObject, 'String', 'Stop');
else
    buttonState=1;
    set (hObject, 'String', 'Start');
end

It almost does that, but when I press exit, I get the error on line 46.

[Jan]

Please do not let us guess, which of the lines is the line 46. And post a copy of the complete error message.

Answer 1

[Jan]

Using the debugger is the standard for solving such problems. Type in the command window:

dbstop if error

Then run the code again until the error appears. Now you can inspect the locally used variables, I guess the handles struct is the problem and handles.axes1 does not contain a valid axes -handle.

[Bachtiar Muhammad Lubis]

@Jan : How could a handles.axes doesn't contain a valid axes handle sir ? i am facing this error now