hi guys, i want to plot in GUI, i've tried this code.

function calcbutton_Callback(hObject, eventdata, handles)
      dis = sqrt((handles.mydata.b)^2 -4*(handles.mydata.a)*(handles.mydata.c));
      ans1 = (-(handles.mydata.b) + dis) /(2*(handles.mydata.a));
      ans2 = (-(handles.mydata.b) - dis) /(2*(handles.mydata.a))
      set(handles.ans1, 'String', ans2);
      set(handles.ans2, 'String', ans1);

function plotbutton_Callback(hObject, eventdata, handles)
      x=0:10;
      plot(x,handles.ans1, handles.axes1);
      hold on;
      plot(x,handles.ans2, handles.axes2);

But it displays:

Error using plot
Data must be a single matrix Y or a list of pairs X,Y.

Answer 1

[Image Analyst]

Get rid of the calls to set and just do this:

handles.ans1 = (-(handles.mydata.b) + dis) /(2*(handles.mydata.a));
handles.ans2 = (-(handles.mydata.b) - dis) /(2*(handles.mydata.a))

In the second callback do this instead:

x=0:(length(handles.ans1) - 1);
plot(x,handles.ans1, handles.axes1);
grid on;
hold on;
x=0:(length(handles.ans2) - 1);
plot(x,handles.ans2, handles.axes2);

If it still doesn't work, then find a call to guidata() somewhere in your code and copy it to the last line of the callback that assigns handles.ans1 and handles.ans2.

[Walter Roberson]

guidata(hObject, handles)

[Image Analyst]

Put this inside calcbutton_Callback(), not inside plotbutton_Callback(), though it doesn't hurt to have it there in case you ever change or add to handles inside that functions.

[Image Analyst]

There's something you're not showing us. Attach the .m file and the .fig file, and any data files it reads in.

[Anisio Gomes]

I attached the m,fig,jpg files

Answer 2

[Anisio Gomes]

Thanks Image Analyst... I've tried

function calcbutton_Callback(hObject, eventdata, handles)
   dis = sqrt((handles.mydata.b)^2 -4*(handles.mydata.a)*(handles.mydata.c));

     handles.ans1 = (-(handles.mydata.b) + dis) /(2*(handles.mydata.a));

     handles.ans2 = (-(handles.mydata.b) - dis) /(2*(handles.mydata.a))

function plotbutton_Callback(hObject, eventdata, handles)

x=0:(length(handles.ans1) - 1);
plot(x,handles.ans1, handles.axes1);
grid on;
hold on;
x=0:(length(handles.ans2) - 1);
plot(x,handles.ans2, handles.axes2);
guidata(hObject, handles)
However, the error keep showing up..... :(

[Walter Roberson]

After the assignment to handles.ans2 you need to add

guidata(hObject, handles);

... like we said earlier.

[Image Analyst]

Let us know if it's fixed now.

[Anisio Gomes]

I've tried it and the problem remain here is the files