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When I'm running this code, the variable "iter" updates in the outer while loop but it's not updating in the inner while loop. Iter in the outer while loop returns 1, 2, 3, 4, 5 after 5 iterations but the iter in the inner while loop returns 1, 1, 1, 1, 1 after 5 iterations. Is there a way to update iter in the inner while loop?

Here's while loops part of my code:

iter = 1; % Initial iteration

while iter<6 % Outer while loop

while n*dTm<W

n = n+1;

if n==16

break

end

while d>.05*dTm % Inner while loop

phi = atand((vi+vc)/(w*r*.2*iter));

alpha = theta - phi;

Cl = CL(find(ALPHA_CL > alpha, 1));

dTa = .5*rho*(w*r*.2*iter)^2*c*dr*Cl;

dTm = 4*pi*r*.2*iter*dr*rho*vi*(vi+vc);

d = abs(dTm-dTa);

vi = vi+1;

if vi==1000

break

end

end

vi;

dTm;

end

x(iter, 1) = iter;

x(iter, 2) = vi;

x(iter, 3) = dTa;

x(iter, 4) = dTm;

iter = iter+1;

end

Jon
on 16 Dec 2020

If you want iter to increment inside of the inner loop you have to move the statement

iter = iter+1;

inside of the inner loop.

However, although I don't know the details of what you are doing here, it seems like you may want iter to stay constant while the inner loop iterates. So maybe your code is already doing what you want.

Also, if you know you want a loop to execute a known number of times, 6, in your case, you should use a for loop instead of a while loop, e.g. for k = 1:6 .... end

Walter Roberson
on 16 Dec 2020

while n*dTm<W

n = n+1;

if n==16

break

end

After the end of the inner loop, you are not changing n, dTm, or W, so if you left the inner loop because n*dTm<W was false, it will still be false.

If you left the inner loop because n == 16 was true, then n will be incremented to 17 because the n=n+1 is before the test, so you will not break because of that. You will, though, then execute the inner loop with n = 17, leaving it when n*dTm<W becomes false, and then the outer iteration after that, you are back to the problem I described in the first paragraph.

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