How do I refresh data in an axes in Matlab GUI?

I am trying to update a graph every time the value of variable "sectors_all" changes or the button "select" is pressed.

How do I change the data on the graph without creating a new UI every time?

userInterface = figure('Name','Solution selector window');
flightDataPlotPosition = [.1 .5 .375 .4];
ax = axes('Parent',userInterface,'Position',flightDataPlotPosition);
hold on

subplot(ceil(sqrt(size(sectors_all,1))),ceil(sqrt(size(sectors_all,1))),1, 'Position',flightDataPlotPosition);
hold on;

topPanel = uipanel(userInterface,...
           'Position',[0 .95 1 .05]);

% Code for select button in the top panel        
selectButton = uicontrol('Parent',topPanel,'Style','pushbutton','String',"Select",...
              'Units','normalized',...
              'Position',[.325 .25 .05 .5],...
              'Callback', @selectSolution);

% callback function for select button in the top panel
function selectSolution(source,event)
    display('select button pressed')
end

[Adam]

You don't seem to be actually plotting any data in that code, just creating a subplot axes.