findobj to refresh lines in a graph

Question

fjnb86 2011-10-18

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/18574-findobj-to-refresh-lines-in-a-graph

Hello, I am working in a GUI and I want to add a new plot in a figure (axis) represented before.

The problem is that can not find the way to delete last function plotted for repeat the action but dont "hold on" the plots

Code for the button:

   function pushbutton10_Callback(hObject, eventdata, handles)
axes(handles.axes2) %active the figure
pos=getappdata(0,'cursorposition');  %this works!
%plot lines
line1 = hline(pos(1)); this works too! 
line2 = vline(pos(2));
guidata(hObject, handles);

If I click again I need to use findobj to localize line1 and line2 and delete it if they exist. Ive tried using findobj('type','line') but I couldnt find.

this psuedo code it has to be before plot:

if line1 or line2 exist then
delete(line1)
delete(line2)
end

maybe it is easier if I create a handle for this ?

thanks!

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Daniel Shub 2011-10-19

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/18574-findobj-to-refresh-lines-in-a-graph#answer_25043

在 MATLAB Online 中打开

Yes, it is easier if you create a handle ...

if isfield(handles, 'line1') && ishandle(handles.line1)
   delete(handles.line1)
end
if isfield(handles, 'line2') && ishandle(handles.line2)
  delete(handles.line2)
end
handles.line1 = hline(pos(1)); this works too! 
handles.line2 = vline(pos(2));

3 个评论
显示 1更早的评论隐藏 1更早的评论

Daniel Shub 2011-10-19

I don't quite understand your problem. I am guessing somehow the gui is being saved so handles has the field line1, but that line1 does nto exist. I have edited the answer to include ishandle(handles.line1). This should hopefully fix it.

fjnb86 2011-10-20

exactly, now it works!

;)

请先登录，再进行评论。

Answer 2

Olaf 2011-10-19

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/18574-findobj-to-refresh-lines-in-a-graph#answer_25042

Hi A possible solution might be to use Matlab graphic handles property called 'Tag'. By default it is empty and upon creation of your lines you can assign each of your lines a unique tag, e.g. set(line1, 'Tag', 'myUniqueHLineTag'); Then, when you want to test the existence of any of these lines, you can search through the handles obtained by findobj for this tag.

Olaf