An increasing length vector error to find the last component (made through a loop)

Hello all,

I have created a vector "X" with an initial value for "X1", through a loop, I am adding some other components to this vector. So, at the end of loop: for q=1:n

I should have a vector of length (n+1) for sure. However, for example for n=20, for some runs I have it correct and the vector is made OK. But, some another times that I push the run button (for the same code), I get the following error:

Attempted to access x1(6); index out of bounds because numel(x1)=5. or Attempted to access x1(10); index out of bounds because numel(x1)=9. or....

Do any of you know why? I mean why the result of this code is not consistent?

Regards, Mahdi

[the cyclist]

Can you post the code? It is very difficult for us to guess the problem with out seeing it.