Why the counter does not work in this while loop?

Question

In this code, the loop is still working to compute the ratio r according to the given condition of the absolute error until getting r=1.6180 at i=16, but here it gives the result at i=3 (initial i) which means the counter does not work. what is wrong here?

clc
clear
//funcprot(0)
function f=fib(n)
    f(1)=1
    f(2)=1
    for i=3:n
        f(i)=f(i-1)+f(i-2)
    end
endfunction
//n=5
//disp(fib(n))

//compute golden ration
//compute golden ration

r0=0
r1=1       //ratio y2/y1
 //err=r1-r0
 i=3
while abs(r1-r0)>10^(-5)
r1=r0
r=fib(i)/fib(i-1)
 i=i+1
end
//f(16)/
disp(r)

---

Thanks S. Gougeon. Also after clearing r1=r0 from the loop, I am getting the wrong result (r is the golden ratio of fibonacci sequence=(1+sqrt(5))/2).

clc
clear
//funcprot(0)
function f=fib(n)
    f(1)=1
    f(2)=1
    for i=3:n
        f(i)=f(i-1)+f(i-2)
    end
endfunction
//n=5
//disp(fib(n))

//compute golden ration
//compute golden ration

r0=0
r1=1       //ratio y2/y1
 //err=r1-r0
 err=1
 i=3
while abs(err)>10^(-5)
   //r1=r0
r=fib(i)/fib(i-1)
err=r-r0
 i=i+1
end
//f(16)/
disp(r)

Answer 1

In the while loop, setting r1=r0 yields r0-r0=0 for the next while condition (since r0 never changes), and so escapes the while condition and loop.