Hi, Yasir-

Sorry for the delay in reply to this. Since I really know nothing about these quantities, I was trying to read a bit more about them. You example is nice, too, thanks.

One thing to note is that there are apparently 2 different ways of defining LZC: the LZ-76 and LZ-78 (I think the numbers denote papers form 1976 and 1978, respectively). They produce different dictionaries of terms and different complexity values-- this was something that was not explained so clearly everywhere online (what? the web isn't always clear and precise??!), but this article:
[www.mitpressjournals.org]
in particular helped clarify the distinction a bit. For example, I *think* that what you describe with your example is more along the lines of LZC-76.

This is probably something that could be added to AFNI, but I have a bit of a backlog of things to do at this moment...

The fSD that you describe sounds to me like basically fALFF---see for example the Appendix here:
[www.ncbi.nlm.nih.gov]
(though it was derived in other papers). This is basically a quantity that describes the relative contribution of a frequency band to the overall sum of amplitudes--- something akin to (but not the same as) the relative power in a band. AFNI's 3dRSFC will also calculate fRSFA, because RSFA is analogous to ALFF (just the L2 norm of frequencies instead of the L1 norm).

--pt