Iterating over an Array Using a “for” Loop.

This is a very basic question and I would appreciate any help. I've written code to calculate the Fibonacci sequence using a “for” loop. I want to display the elements of the sequence whose indices are specified in the array “N”. The problem is that all displayed values are the same as the value associated with the first element of “N”.

N=[10 100 1000];
first=1;
second=1;
for i=1:(N-2)   %The index has to have two terms removed because it starts with 1 and 1 already
        next=first+second;  %The current term in the series is a summation of the previous two terms
        first=second;   %Each term must by iterated upwards by an index of one
        second=next;    %The term that previously was second is now referred to as next
end
for i=1:length(N)
    disp([N(i) next])
end

Thanks

[Donald Hersam]

Thanks for the quick response, but what this loop seems to do is tell me the entirety of the series. I was only looking for a response that returns the value at the 10, 100 and 1000th place mark on the series.

[Maryam Omar Maabreh]

for i=start : step : last+1
    % ...
end

Where step is the increment to i.

In your case, your looking for

for i=1 : 10 : 10001
    i = i*10;
    % ...
end 

Answer 1

[Image Analyst]

Donald, regarding your new "Answer", you can do it like this:

N=[10 100 1000];
for n = 1 : length(N)
  first=1;
  second=1;
  for k = 3 : N(n)   %The index has to have two terms removed because it starts with 1 and 1 already
    next = first+second;  %The current term in the series is a summation of the previous two terms
    first = second;   %Each term must by iterated upwards by an index of one
    second = next;    %The term that previously was second is now referred to as next
  end
  % Print to command window
  next
end

Answer 2

[MathWorks Support Team]

Use a “for” loop to calculate the elements of the Fibonacci sequence for the maximum value in “N”. Then, use another “for” loop to display the values by indexing into the calculated sequence.

N = [10 100 1000]; 
f(1) = 1; 
f(2) = 1; 

for i = 3:max(N) 
   f(i) = f(i-1) + f(i-2); 
end 

for i = 1:numel(N) 
    disp(f(N(i))) 
end