Extrapolating a loop to a threshold

Hi, I have a problem in estimating some data up to a threshold. Basically, what I would like to do is pass a data value to an equation and then loop the calculation until it reaches a threshold. Can anyone please help?

Answer 1

[Thorsten]

y = 2;
threshold = 10; % sample threshold
while y < threshold
   y = y^2 % sample calculation, put your function here
end

[Andrew Wileman]

That's great, thank you very much Thorsten.