appending to vector in a for loop

Hello I have this code so far, it wont run because the number of elements of winddivergencex is not the same number of elements as n because of the differentiation, how can I get this to work? I want to add a zero term to the end of vector such that the elements are the same length. Thanks

 for n = 1:30

     winddivergencex(n)= (diff(Ui(min(dataind{n}):(max(dataind{n})))))./(diff(longm(min(dataind{n}):(max(dataind{n}))))); 

 end

[Geoff Hayes]

Shrobhit - what are the dimensions of your vectors like dataind? Note that you say that the number of elements of winddivergencex is not the same number of elements as n. Which elements of winddivergencex (the row or column)? Note also that n is changing on each iteration of the loop...