Plotting onto specified axes in Matlab GUIDE - matlab

Question

I have the following code for a pushbutton using Matlab GUIDE.It is supposed to plot a rotating arrow which rotates to the angles specified by theta 1 and theta 2.
function start_pushbutton_callback_Callback(hObject, eventdata, handles)
% hObject handle to start_pushbutton_callback (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
handles = guidata(hObject);
theta1 = handles.xy_angle;
theta2 = handles.yz_angle;
delay = handles.speed;
axes(handles.axes_turntable_xy);
R= 1; %Radius of the turntable
E=[0;0;0];
C=[-2;0;0];% points on the X axis
D=[2;0;0]; % points on the X axis
G=[0;2;0]; % points on the Y axis
H=[0;-2;0];% points on the Y axis
for th =1:1:theta1
clf;
Radius =1;
[x,y,z] = cylinder(Radius,200);
plot(x(1,:),y(1,:))
axis equal
L1= [R*cosd(th);R*sind(th);0];
drawvector(E,L1); % call the drawvector function, as previously
line([C(1),D(1)],[C(2),D(2)]);
line([G(1),H(1)],[G(2),H(2)]);
axis([-2 2 -2 2]);
grid on;
pause(delay);
end;
axes(handles.axes_turntable_yz) ;
R= 1; %Radius of the turntable
E=[0;0;0];
C=[-2;0;0];% points on the X axis
D=[2;0;0]; % points on the X axis
G=[0;2;0]; % points on the Y axis
H=[0;-2;0];% points on the Y axis
for th =1:1:theta2;
clf;
Radius = 1;
[x,y,z] = cylinder(Radius,200);
plot(x(1,:),y(1,:))
axis equal
L1= [R*cosd(th);R*sind(th);0];
drawvector(E,L1); % call the drawvector function
line([C(1),D(1)],[C(2),D(2)]);
line([G(1),H(1)],[G(2),H(2)]);
axis([-2 2 -2 2]);
grid on;
pause(delay);
end
However, I am facing two problems with this code:
1) It simply plots onto a new matlab figure instead of plotting it on axes_turntable_xy-
2) It displays the following error afer executing till the line axes(handles.axes_turntable_yz). The error is as follows:
Error using axes
Invalid object handle
Error in turntable_interface_model>start_pushbutton_callback_Callback (line 235)
axes(handles.axes_turntable_yz) ;
Error in gui_mainfcn (line 96)
feval(varargin{:});
Error in turntable_interface_model (line 42)
gui_mainfcn(gui_State, varargin{:});
Error in
#(hObject,eventdata)turntable_interface_model('start_pushbutton_callback_Callback',hObject,eventdata,guidata(hObject))
Error while evaluating uicontrol Callback
Can anyone help with this?

Answer 1

Okay, I debugged the code and this was the problematic line in the above code:
for th =1:1:theta1
clf;
Radius =1;
[x,y,z] = cylinder(Radius,200);
The working code is:
for th1 =1:1:theta1
cla(handles.axes_turntable_xy); %clears the figure handles.axes_turntable_xy
Radius =1;
[x,y,z] = cylinder(Radius,200);
This clears the figure I am plotting in in Matlab, not some unspecified figure! Although it's still hard to understand why Matlab was plotting these commands in a new figure inspite of making axes.turntable_xy the current axes.