How can I swith between plots in the same plot window?

Just as a note for future reference (in response to your email): I am receiving notifications, although I did choose to disable email notifications. That way I can keep track of the questions that get updates, but only when I have time to actually reply.

The code below is the adapted version. If you make sure h is a matrix where each row should be displayed simultaneously, this will do that for you. Don't forget to explicitly code a range for the axes (like I did with axis([1 4 0 1]) below). This will prevent the axes to jump around when you hide plots.

f=figure(1);clf(1)
y1=rand(4,2);
y2=rand(4,2);
y3=rand(4,2);
x=1:4;
h=plot(x,y1,'y',x,y2,'k',x,y3,'r');

h=reshape(h,2,3);

axis([1 4 0 1])
handles=struct('f',f,'h',h);
handles.visible_index=1;%keep track of which plot is selected
set(h,'Visible','off');
set(h(handles.visible_index,:),'Visible','on');
guidata(f,handles)
set(f,'KeyPressFcn',@SetVisibility)
function SetVisibility(hObject,eventdata)
switch eventdata.Key
    case {'uparrow','up'}
        direction=1;
    case {'downarrow','down'}
        direction=-1;
    otherwise
        return
end
handles=guidata(hObject);
%set the old plot to invisible
set(handles.h(handles.visible_index,:),'Visible','off');
%find the new index to be set
handles.visible_index=mod(handles.visible_index+direction,size(handles.h,1));
if handles.visible_index==0,handles.visible_index=size(handles.h,1);end
%set the new plot to visible
set(handles.h(handles.visible_index,:),'Visible','on');
%optional: set the title to the index value
title(sprintf('selected plot: %d',handles.visible_index))
guidata(hObject,handles)
end