you can use hold on to keep adding to these plots
x = 1:10 %time
for i =1:3
y(i,:)=1*x+i;
z(i,:)=2*x.^2+100+i;
end
[ax h1 h2]=plotyy(x,y(1,:),x,z(1,:));
ylabel(ax(2),'Hits');
ylabel(ax(1),'Displacement (in)');
xlabel(ax(2),'Time (sec)')
hold(ax(1),'on');
hold(ax(2),'on');
plot(ax(1),x,y(2,:))
plot(ax(2),x,z(2,:))
plot(ax(1),x,y(3,:))
plot(ax(2),x,z(3,:))
not the cleanest example but it shows how to add to existing and when run that everything stacks appropriately.
