clc
clear all
close all
%%% Thin Lens Focal Plane
f=[1 2 5 3];
%%% Distance betwin Object and Thin Lens
t=[2 1 2 3];

%%% Hieght of Object
ynock(1)=3;
yras(1)=0;
%%% Angle of incidence Ray (Radian)
u(1)=0.5;

[m,n]=size(f);

for i=2:n+1
    yras(i)=yras(i-1)+u(i-1).*t(i-1);
    phi(i-1)=1./f(i-1);
    u(i)=u(i-1)-(yras(i)*phi(i-1));

end;
image=abs(yras(i)/u(i));


for i=2:n+1
    ynock(i)=ynock(i-1)+u(i-1).*t(i-1);
    phi(i-1)=1./f(i-1);
    u(i)=u(i-1)-(ynock(i)*phi(i-1));
end;
hieght=abs(ynock(i)+u(i)*image);
hold on
grid on
y=-ynock(1):0.01:ynock(1);
ylim([-max(abs(ynock)) max(abs(ynock))]);

plot(0,y,'--bs',0,-y,'--bs');
for j=1:n
    y=-abs(ynock(j)):0.01:abs(ynock(j));
    plot(sum(t(1:j)),y,'--rs',sum(t(1:j)),-y,'--rs');
end;
y=-hieght:0.01:hieght;
plot(image+sum(t),y,'--gs');