[R] Computing fundamental harmonics from a periodogram

[hadley wickham]

Dear all,

I'm trying to finding the fundamental harmonics (ie. peaks in a
periodogram) from a time series (extracted from an mp3).  For example,
if I look at

spectrum(fdeaths, spans = c(3,3))

I'd say the fundamental harmonics are about 1, 2, 3.5 and 4.5 - but
how can I extract these automatically?  (preferably with some
heuristic for choosing the smoothing spans too)

I'm aware of heuristic methods for finding peaks for general sequences
(as found by searching for peaks on R-help) but I have a feeling
there's something with some theoretical justification for the case of
periodograms.  Could anyone point me in the right direction in terms
of theory or an R package that implements an approach?

Thanks,

Hadley