Fibonacci Series using while loop .

This is the code I have written for the generation of Fibonnaci series for n < 200 using while loop .

%% Fibonacci series using while loop %%

n=200 ;

fibo = [1,1] ;

i = 3 ;

while i < n

fibo(i) = fibo(i-1)+fibo(i-2);

i=i+1 ;

end

But it gives me 0 for all values and gives garbage values for last few elements . What could be possible reason for this ?

[Torsten]

But it gives me 0 for all values and gives garbage values for last few elements . What could be possible reason for this ?

The reason is that n is too large.

[Siddhesh]

Thank you for the help sir .

Answer 1

[Aditya Singh]

Hi,

I understand you are getting garbage values. The issue in your code is that you have not initialized the fibo array with enough elements to store the Fibonacci series up to n. As a result, when you try to access elements beyond the initial two elements, you encounter garbage values. The following code works fine.

n = 200;
fibo = zeros(1, n); % Initialize the fibo array with zeros

fibo(1) = 1;
fibo(2) = 1;

i = 3;
while i <= n
    fibo(i) = fibo(i-1) + fibo(i-2);
    i = i + 1;
end

% Display the Fibonacci series
disp(fibo);

   1.0e+41 *

  Columns 1 through 19

    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000

  Columns 20 through 38

    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000

  Columns 39 through 57

    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000

  Columns 58 through 76

    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000

  Columns 77 through 95

    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000

  Columns 96 through 114

    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000

  Columns 115 through 133

    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000

  Columns 134 through 152

    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000

  Columns 153 through 171

    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000

  Columns 172 through 190

    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0001    0.0001    0.0002    0.0003    0.0005    0.0008    0.0013    0.0021    0.0033    0.0054    0.0087    0.0141    0.0228

  Columns 191 through 200

    0.0369    0.0597    0.0966    0.1564    0.2530    0.4093    0.6623    1.0717    1.7340    2.8057

Also, just an additional information, keep in mind the range of integer or data type you are using. After a certain time, they would overflow and give you garbage values.

Hope it helps!

Answer 2

[Mahesh Chilla]

Hi Siddhesh!

To generate Fibonacci series for n < 200 using while loop, your code is correct, you might have missed noticing the mulitplying factor in the output that is 1.0e+41.

%% Fibonacci series using while loop %% 
n=200 ; 
fibo = [1,1] ; 
i = 3 ;
 while i < n 
     fibo(i) = fibo(i-1)+fibo(i-2);
     i=i+1 ;
 end 
 disp(fibo);

   1.0e+41 *

  Columns 1 through 19

    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000

  Columns 20 through 38

    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000

  Columns 39 through 57

    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000

  Columns 58 through 76

    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000

  Columns 77 through 95

    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000

  Columns 96 through 114

    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000

  Columns 115 through 133

    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000

  Columns 134 through 152

    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000

  Columns 153 through 171

    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000

  Columns 172 through 190

    0.0000    0.0000    0.0000    0.0000    0.0000    0.0000    0.0001    0.0001    0.0002    0.0003    0.0005    0.0008    0.0013    0.0021    0.0033    0.0054    0.0087    0.0141    0.0228

  Columns 191 through 199

    0.0369    0.0597    0.0966    0.1564    0.2530    0.4093    0.6623    1.0717    1.7340

You can also use the other method suggested by Aditya, which gives the same output as your method.

The following code verifies both methods

n = 200;
fib = [1, 1];
i = 3;
while i < n
    fib(i) = fib(i-1) + fib(i-2);
    i = i + 1;
end
% The resulting Fibonacci sequence is stored in the 'fib' array
n = 199; %changing n to 199, because the 'fib' array is of size 199
fibo = zeros(1, 199);  % Initialize the 'fibo' array with zeros
fibo(1) = 1; 
fibo(2) = 1;  
i = 3;
while i <= n
    fibo(i) = fibo(i-1) + fibo(i-2);
    i = i + 1;
end
% The resulting Fibonacci sequence is stored in the 'fibo' array
% To check if 'fib' and 'fibo' are the same.
isequal(fib,fibo)

ans = logical
   1

Hope this helps,

Thank you!!

Answer 3

[Yash]

I made this code by myself only and found it correct for every possible value :

N = 200;
a = zeros(1,N);
a(1) = 1;
a(2) = 2;
count = 3;
while (count<=N)
    a(count) = a(count-1)+a(count-2);
    count = count + 1;
end
disp(a(N));

   4.5397e+41

I hope this code is helpful for everyone.