http://www.grmtools.org/products/stbundle/stbundle.html The original fsig framework and the earlier PVS opcodes (pvsanal, pvsfread, pvsinfo, pvsynth, pvsadsyn, pvsmaska, pvscross, pvsftw and pvsftr) were created by Richard Dobson and released in Csound 4.13. Victor Lazzarini has since added numerous PVS opcodes in Csound 5 (particularly those discussed here). John Ffitch has also contributed with his pvscent opcodes, although this opcode is not discussed here (for details see http://www.csounds.com/manual/html/SpectralRealTime.html).
 Davis Pyon - http://www.davixology.com/csound~.html
 My thanks to Richard Dobson who suggested this method of dealing with the frequency data on the Csound mailing list.