Terje Mathisen <terje.mathi...@tmsw.no> writes: >One of the good points about Google's smear is the fact that they use a >half cosine to distribute the offset, which means that they have a time >function which is both continuous and monotonic, as well as having an >infinite number of defined derivatives, i.e. it is maximally smooth.
Doesn't it only have two smooth deritives at the end points or [-w:w]? The usual function is constant 1 with all derivatves zero, and so this is what the derivative should be at the endpoints. They use (1.0 - cos(pi * t / w)) / 2.0, which is 1 at both end point, has first derative zero, but the second deritive is -pi*pi/w/w. (It should be possible to stitch together something that is infinitely smooth, probably using exp(-1/(x*x)), but it would requite a bit more work.) David. _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions