When showering. I thought of something being really strange. I recall that Matt said that ideally SDRs are ~4% dense somewhere in HTM School. But in practice I find that SDRs are mostly ~10% dense (Maybe caused by TMs predicting all possible future instead of one possible future). For example. In my Grid Cells experiment, the input SDR is 12.5% dense and the predicted SDR has a density of 17%. And in my NLP experiment, although the input SDR is ~3.5% dense. The generated SDR is 9~15% dense. And in my ECG experiment. 4% density is way too low to be usable, sending a SDR with ~10% density yields a better performance.
Have I remember anything wrong? Or maybe is 10% a better value?