Lee,

You can increase performance of the algorithm you show by using a rolling buffer concept instead of moving all of the data each sample period. I discussed how this is done conceptually here in this discussion about averaging.

Later in that same thread Hans showed some code which I believe implements the concept in assembler. See it here.

Just look at the above with the eye to seeing how to handle a rolling buffer of recent samples without having to move all the data. The filters we were discussing there were simple averaging filters.

Michael Karas