Bob McGwier wrote: > > I suggest that the best algorithm for this would be the rank order > mean alternated with the max so long as you are going to insert > "heuristic grass". So it would be max, ROM, max, ROM, ..... > > > Let [B1, B2, B3, B4, ... BN] be powers of five adjacent bins. > > Put them in rank order > > [R1, R2, R3, R4, ... RN] > > If N is even, the rank order mean is (R_(N/2) + R_/(N/2 +1)*0.5. > If N is odd, the rank order mean is R_(N/2 +0.5) > > But I still see a problem: > > I suggest that in order to prevent "scalloping" of a swept tone across > this algorithm or any other like it, that some "bin" in the lossy > compression set of bins must ALWAYS be forced to take on the large of > the power spectrum otherwise your alternative min/max/min/max might > jump up and down as you sweep a tone through it. Or did I miss > something? > > Bob I love that phrase, Bob. "Heuristic grass".
I think that the real answer is to "play with it, and see what best suits the application". Ranking the bin might end up being expensive. I'd probably use qsort(), but I can't remember what its computational complexity is. Just looked it up. Worst case is O(N**2), and best-case is O(NlogN). For worst-case, that's rather brutal at 4M bins (and even worse at my maximum of 16M bins). This discussion has ended up being much more fascinating than I had predicted. Keep it up everybody! -- Marcus Leech Principal Investigator, Shirleys Bay Radio Astronomy Consortium http://www.sbrac.org _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
