# I'm Trying to run iterations until convergence.

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Cole Zajack on 23 Sep 2020
Commented: Dana on 23 Sep 2020
Hello,
So baically I have a problem where I am guessing an initial weight (Wi). and then I have to plug in (Wi) into an Equation that looks like this. W6=Wi*(0.95)*(0.97)*...
Then I want to take the answer for W6 and use it in this equation (Y=W6/Wi). Then take the answer for Y plug it into another equation F=(1-Y)*1.06.
Lastly from there, take all these answers I just found and plug into Wtogw=(25000)/(1-F-0.457).
Now. Whatever answer I get for Wtogw, I want to use that as my new Wi and redo the process unti the answer I get for Wtogw is equal to Wi.
I have posted what I have so far. The whole first part of code is just setting variables which have known values. Please tell me what I am doing wrong/missing for the "while" loop.

Dana on 23 Sep 2020
Edited: Dana on 23 Sep 2020
Well, you haven't actually told us what the problem you're encountering is, but right away I can see several problems. First, your while loop condition is i<=maxIter, but you haven't defined i anywhere. As a result, MATLAB is using the built-in i, i.e., sqrt(-1). In this case, when checking whether i<=maxIter, MATLAB only considers the real part of i, which is 0, and therefore (i<=maxIter) evaluates to true.
Furthermore, since i isn't changing inside the loop, it will always be the case that i<=maxIter, and therefore your loop will never end.
If you want to do this loop a set number of times, you should use a for loop, not a while:
for i = 1:maxIter
<stuff>
end

Dana on 23 Sep 2020
Where you had it before, or really anywhere before the start of the loop.
Cole Zajack on 23 Sep 2020
Do you know why I am still getting an error for maxIter?
Dana on 23 Sep 2020
MATLAB interprets the statement i<=maxIter as, "Check whether i is less than or equal to maxIter; return true if it is, return false if it's not."
That's not what you want to do here. Rather, you simply want to define maxIter, just as you did originally:
maxIter = 100;

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