How to randomize points using a GUI

I have created a GUI that has a push button that you can add points to the graph and a button to randomize the added point. I had to plot a singular point and then later created a function that adds points. when I click the randomize button it only randomizes the first point I created but I need it to randomize for all of the points that get added. I'm not sure how to do so but here is what I have created so far:

f= figure;
ax= axes('Parent',f,'Position',[0.05, 0.25, 0.9, 0.7]);
xlim = ([0,1]);
ylim = ([0,1]);
x = 0.25;
y = 0.55;
point_plot_handle = plot(x,y,'d','MarkerFaceColor','m','MarkerSize',75);
hold on;

my_button = uicontrol('style','pushbutton');
set(my_button, 'units', 'normalized', 'position', [0.05,0.05,0.3,0.15])
set(my_button, 'string','Add Point')
set(my_button, 'callback', @add_point)

my_second_button = uicontrol('style','pushbutton');
set(my_second_button, 'units', 'normalized', 'position', [0.35,0.05,0.3,0.15])
set(my_second_button, 'string', 'Clear')
set(my_second_button, 'callback', @clear)

my_third_button = uicontrol('style', 'pushbutton');
set(my_third_button, 'units', 'normalized','position', [0.65,0.05,0.3,0.15])
set(my_third_button, 'string', 'Randomize')
set(my_third_button, 'callback', {@randomize,point_plot_handle});

function randomize(sender, eventdata, h)
new_point = randn(2,1);
set(h,'XData', new_point(1), 'YData', new_point(2));
end 

function clear(sender, eventdata)
empty = cla;
end 

function add_point(~,~)
  l='od+.';
  plot(rand,rand,l(randi(4)),'MarkerFaceColor',rand(1,3),'MarkerSize',35);
end

Answer 1

[David Hill]

Please accept my previous answer if it was acceptable to you.

GUI

function GUI()
f= figure;
axes('Parent',f,'Position',[0.05, 0.25, 0.9, 0.7]);
x = 0.25;
y = 0.55;
h = plot(x,y,'d','MarkerFaceColor','m','MarkerSize',35);
ax=gca;
ax.XLim = [0,1];
ax.YLim = [0,1];
hold on;
my_button = uicontrol('style','pushbutton');
set(my_button, 'units', 'normalized', 'position', [0.05,0.05,0.3,0.15])
set(my_button, 'string','Add Point')
set(my_button, 'callback',@add_point)
my_second_button = uicontrol('style','pushbutton');
set(my_second_button, 'units', 'normalized', 'position', [0.35,0.05,0.3,0.15])
set(my_second_button, 'string', 'Clear')
set(my_second_button, 'callback', @clear)
my_third_button = uicontrol('style', 'pushbutton');
set(my_third_button, 'units', 'normalized','position', [0.65,0.05,0.3,0.15])
set(my_third_button, 'string', 'Randomize')
set(my_third_button, 'callback', @randomize);
function randomize(~,~)
  for k=1:length(h)
   h(k).XData=rand;
   h(k).YData=rand;
  end
end 
function clear(~,~)
  cla;
  h=[];
end 
function add_point(~,~)
  l='od+.';
  h=[h,plot(rand,rand,l(randi(4)),'MarkerFaceColor',rand(1,3),'MarkerSize',35)];
end
end

[Amanda]

it keeps telling me there is an error in line 26 'for k=1:length(h)'

[Amanda]

my professor talked about storing it in an array by storing all the handles of my plots in it then addind the new plot handle to the end of the existing one. his example was plot_handle_array= [plot_hanlde_array new_plot_handle]. I dont understand this or how to do it

[David Hill]

The above works. I am storing all the lines in variable h. Just run the function GUI.