Code for DFT

[Doug Welch <welch@physics.mcmaster.ca>]

One of the best references for analysing non-uniformally
spaced time-series is the work of Roberts, Lehar, and Dreher
1987, Astronomical Journal, 93, 968. 

http://adsabs.harvard.edu/cgi-bin/nph-bib_query?
bibcode=1987AJ.....93..968R&db_key=AST

Their original Fortran code, which includes a DFT program,
can be downloaded from:

http://physun.physics.mcmaster.ca/Fac_Welch/cleanprg.tar.gz

Clean allows you to remove, to some degree, the effects of
the spectral window - due to the arrangement of observation times -
on the power spectrum.

Cheers,
Doug