- Google Blog: Handling Leap Seconds
lie(t) = (1.0 - cos(pi * t / w)) / 2.0
- news.ycombinator.com: Why use cosine to interpolate v.s. a linear smear?
- The cosine is pretty much the perfect interpolation function when you want the derivatives to be zero at the boundaries. It's by definition frequency-bound (to itself, of course). It's derivatives are defined and continuous to any degree you want. And it's easy to express and understand. You pick other functions only when it's too expensive.