gui error

this programme is for flatfire trajectory of projectile,i solved it using odesolver(ode45)with event location;i made its gui by dirrectly drag and drop buttons from options and linked this programme in to the gui programme with pushbutton. i define function which odesolver will call just above the pushbutton and put the solver programmme inside the push button. i am taking some input from user which is being used in the programme .so that after pressing button it can execute the programme.but i found an error.if i simply(not from gui) run this programme from .m file it doesn't give error.this is the error which command window is showing;

??? Reference to a cleared variable handles.

Error in ==> guiflatfiredragwind>pushbutton1_Callback at 257 v0 = str2num(get(handles.edit1,'String'));

this is the programme which i have defined, function [value,isterminal,dircn] = fnflatfiredragwind(t,c,flag,w1,w2,w3,k) g = 9.8; % c(1) = x; c(2) = dx/dt = vx ; c(3) = y ; c(4) = dy/dt = vy ; c(5) = w % c(6) = dc/dt = vc

if nargin<7 isempty(flag)

    value = [c(2); -k*(c(2)-w1)^2; c(4); (-k*(c(2)-w1)*(c(4)-w2))-g; c(6); -k*(c(2)-w1)*(c(6)-w3)];
else
    switch flag
        case 'events'
            value = c(3);
            isterminal = 1; 
            dircn = 0;
        otherwise
            error('function not programmed for this event');
    end
end

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

disp('programme for simple trajectory using ode solver') % here tspan is the approximation time for the event occur i-e y = 0; tspan = [0 10]; % for the graph should be smooth time approximation must be near flight % time

v0 = str2num(get(handles.edit1,'String'));

theta = str2num(get(handles.edit2,'String'));

w1 = str2num(get(handles.edit3,'String'));

w2 = str2num(get(handles.edit4,'String'));

w3 = str2num(get(handles.edit5,'String'));

k = str2num(get(handles.edit6,'String'));

c0 = [0; v0*cos(theta); 1; v0*sin(theta); 0; 0];

options = odeset('events','on');

[t,c,te,ze,ie] = ode45('fnflatfiredragwind',tspan,c0,options,w1,w2,w3,k);

how will i solve this problem; reply soon, thanks pawan kumar

[Jan]

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Answer 1

[Jan]

The error message seems to be descriptive:

 ??? Reference to a cleared variable handles.
 Error in ==> guiflatfiredragwind>pushbutton1_Callback at 257
 v0 = str2num(get(handles.edit1,'String'));

Obviously the variable handles is out of date. The description "if i simply (not from gui) run this programme from .m file" is not precise enough to find the cause of this problem. I suggest to use the debugger:

dbstop if error

Then Matlab stops, if the problem occurs and you can inspect the current variables.