From: hadley wickham <h.wickham@...>
Date: 2006-08-07T23:47:26+09:00
Subject: Re: nextPowerOf2(n)

> Can someone tell me if there's a better way to do this? It takes a
> number and returns the next power of 2 up (or the original if it was
> already a power of 2) Specifically, are there features of Ruby that I
> should be using in this case?

Try this:

def log2(x)
  Math.log(x) / Math.log(2)
end

def nextPowerOf2(x)
  2 ** (log2(x).ceil)
end

Hadley