Undefined function 'stop' for input arguments of type 'double'.

% function frameshow_Callback(hObject, eventdata, handles)
global t  
global t1
t1=timer('TimerFcn',{@timerCallback1,handles},'ExecutionMode', 'fixedDelay','Period', 0.1);
guidata(hObject,handles);
stop(t);
start(t1);
function timerCallback1(hObject, eventdata, handles)
global vid
global t1
global frame
%
if (vid==-1)
    msgbox('first show！');
    stop(t1);
    return;
end
axes(handles.axesshow);
frame=getsnapshot(vid);
imshow(frame);

i use this function to start camera but show the error:

Undefined function 'stop' for input arguments of type 'double'.

Error in colordetect>frameshow_Callback (line 55)
stop(t);

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

Error in colordetect (line 17)
    gui_mainfcn(gui_State, varargin{:});

Error in
matlab.graphics.internal.figfile.FigFile/read>@(hObject,eventdata)colordetect('frameshow_Callback',hObject,eventdata,guidata(hObject)) 
Error while evaluating UIControl Callback.

[per isakson]

My guess is that t in

stop(t);

isn't a timer object

[KSSV]

stop takes object as an input....not a double.....read the documentation of stop

help stop

[KAI XUN CAI]

 t=timer('TimerFcn',{@timerCallback,handles},'ExecutionMode', 'fixedDelay','Period', 0.1);
my t is settings below the program then use global t to use it 
so my t is a object

[KSSV]

what is it's class?

[KAI XUN CAI]

i don't know what did you mean

[Stephen23]

@KAI XUN CAI: using global variables is only going to cause you problems. Relying on global variables is not a good way to write GUI code.

Please show us the complete output of this command:

class(t)