Performance Enhancing Bug

Yeah, the first hypothesis was only applicable to greater-than-1 weight for most kinds of smoothing, which I had thought to be likely.

The second hypothesis still isn't ruled out by that however. "Any GF other than the visited GF would get rounded down to 0" is in fact the most extreme version of what I describe in the second hypothesis.

Now that I know you are using a weight of 1 however... and thinkning about your decay... I'm now quite certain that the real cause is not anything about the smoothing, but the decay. Specifically, applying the operation "foo *= 0.995" where "foo" is an integer in the range 1 to 199, is equilivant to a decrement-by-one operation. When your weight is 1 and your array is an integer one... this means that your decay might as well be "foo *= 0.0" because you're immediately completely erasing the last data point when the next arrives.