I want to hold legends from different callback on same plot.

I have GUI with two PUSHBUTTONs to import the seperate excel files and numbers of CHECKBOX to plot the respective graphs on * same figure* to compare the results. When i click one checkbox it plot the graph with its legend. When i click other checkbox it also plot the graph on same figure but previous legend vanishes and it overrides new legend. I want to keep old legend also to compare the graphs. Please suggest...

if true
 function AFR_Test_Callback(hObject, eventdata, handles)
% hObject    handle to AFR_Test (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
% Hint: get(hObject,'Value') returns toggle state of AFR_Test
handles = guidata(hObject);
a2 = handles.a; 
AFR2 = handles.AFR;
LGD2 = handles.LGD1
if get(handles.AFR_Test,'Value')
figure(1)
hold on
handles.h1 = plot(a2,AFR2,'*--')
handles.rt = legend(LGD2,'Location','southwest','FontSize',8,'FontWeight','bold')
title('AFR')
xlabel('Speed (RPM)','FontSize',8,'FontWeight','bold');
ylabel('AFR','FontSize',8,'FontWeight','bold');
grid on;
hold on;
guidata(hObject,handles);
else 
  if ~isempty(handles.h1)
               set(handles.h1,'Visible','off');
               delete (handles.rt);
  end
end
guidata(hObject,handles);
end 

function AFR_Sim_Callback(hObject, eventdata, handles)
% hObject    handle to AFR_Sim (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
% Hint: get(hObject,'Value') returns toggle state of AFR_Sim
handles = guidata(hObject);
a2 = handles.a; 
AFR_2 = handles.AFR_1;
TEST2 = handles.TEST1
if get(handles.AFR_Sim,'Value')
figure(1)
hold on
handles.h1 = plot(a2,AFR2,'*--')
handles.rt = legend(TEST2,'Location','southwest','FontSize',8,'FontWeight','bold')
title('AFR')
xlabel('Speed (RPM)','FontSize',8,'FontWeight','bold');
ylabel('AFR','FontSize',8,'FontWeight','bold');
grid on;
hold on;
guidata(hObject,handles);
else 
  if ~isempty(handles.h1)
               set(handles.h1,'Visible','off');
               delete (handles.rt);
  end
end

Answer 1

[Bjorn Gustavsson]

It seems that you might get what you want with the legendflex file exchange submission - it allows multiple legends to be added to an axis, seems like what you want to do. It might require some additional adaptations of your code but you'll figure it out.

[Sandy Baha]

Appreciate to your quick answer. I have used legendflex but it still overriding the legends.