MATLAB: Increase a variable proportionally to the squared number of loop repetitions

Question

I have a program that loops ITERATIONS times.

I need to set a variable X that grows proportionally to the number of iterations.

The proportion is:

everytime the variable ITERATIONS is equal to 2^n then set X = n

Example:
ITERATIONS = 2        X = 1
ITERATIONS = 2^2 = 4      X = 2
ITERATIONS = 2^3 = 8      X = 3
ITERATIONS = 2^4 = 16     X = 4

How do I do this in matlab?

I was thinking something like:

If (ITERATIONS = 2^n) X= n

Am I on the right path?

Answer 1

X = log2(ITERATIONS)