> Claudia Beleites <cbeleites <at> units.it> wrote: > > Searching for discrete fourier transform I found lots of information and > > functions - but I didn't see anything that just works > > with irregularly spaced > > signals: all functions I found take only the signal, not its x-axis. > > > > Where should I look? > > Or am I lacking some math that tells how to do without the frequency axis? > > > > Thanks a lot for your help,
Try http://finzi.psych.upenn.edu/R/library/nlts/html/spec.lomb.html or http://finzi.psych.upenn.edu/R/library/cts/html/spec.ls.html (do RSiteSearch("Lomb periodogram") -- the Lomb periodogram does a discrete (although not fast) Fourier transform of unevenly sampled (1D/time-series) data, accounting for the sampling distribution of points (which will the bias the results if you try to do a naive Fourier sum). cheers Ben Bolker ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
