It's actually fairly simple. The curation score that I'm assigning on any post is a multiple of the ratio - [VESTS received] divided by [rshares voted]. Then, that number is averaged over the entire day for each voter. (I multiply VESTS times 1 billion, to get "nanovests" just to reduce the decimal places in the final fraction).

This is a simple average, since it's not weighted by rshares voted. That's on the "to-do list".