matlab GUI: How to store data from push button, to vector (not loosing old values when re-pressing button)

I am new to matlab and i need some help. I am trying to make some program, where you can by 2 clicks on picture get a lenght of something. Basicly it works well, but got a problem when trying to algorytmize it. I use ginput to get coordinates and then pythagorean theorem to work with them and make important variable z2. And those variables I want to store in vector so basicly: I pressed push_button1 click twice on a picture and get some z2,now when i do the procedure again i want to store the new one with the old one in the same vector [z2_old z2_new]. But basicly every time i tried to make something like this the old ones value is rewritten.

This is the code of my push button:

function pushbutton1_Callback(hObject, EventData, handles)

%counter - number of press (working right) 
counter = get(hObject, 'UserData') + 1;
set(hObject, 'UserData', counter);
set(handles.text1, 'String', sprintf('%d', counter));

% - ginput part (working right)

c2 = ginput(2);
   q3 = text(c2(1,1),c2(1,2),'X', ...
                'HorizontalAlignment','center', ...
                'Color', [1 1 0], ...
                'FontSize',10);
   q4 = text(c2(2,1),c2(2,2),'X', ...
                'HorizontalAlignment','center', ...
                'Color', [1 1 0], ...
                'FontSize',10);

%creating the z2 variable(working right)

x2=c2(1,1)-c2(2,1);
 y2=c2(1,2)-c2(2,2);
 z2=sqrt(x2*x2+y2*y2);

% - loop for getting a vector (not ok)

for i=1:counter

      z(i,1)=z2

end

So, basicly when I run the button first time and z2 got for example 130, second time 60, third time 210m I want to get z=[130 60 210], now I am still getting something like 1st press:z=[130], 2nd press: z=[60 60], 3rd press: z=[210 210 210], the old values are every time lost. I tried to fix it many ways but its still not working. Its only a small part of my work and i almost run out of time.

Can someone please tell me how should that loop look like? I tried z(end+1)=z2 , z=[z z2] , but the result is always the same.

Thanks for your help a lot. I really Appreciate it.

Answer 1

[Dishant Arora]

function gui_OpeningFcn(hObject, eventdata , handles)
handles.Z = 0;

 function pushbutton1_callback(hObject , eventdata, handles)
 % Your Code
 z2=sqrt(x2*x2+y2*y2);
 handles.Z = [handles.Z , z2] 
 guidata(hObject , handles);