fftw is a library to do FFTs (fast Fourier transform). It's excellent, but probably not necessary unless you have lots of long series and you use FFT's repeatedly (say in an iterative fitting procedure). R's fft() is essentially instantaneous for most one-shot applications.
Reid Huntsinger -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Tuesday, September 20, 2005 10:32 AM To: R-help mailing list Subject: Re: [R] waveform filtering Quoting tom wright <[EMAIL PROTECTED]>: > On Mon, 2005-19-09 at 10:36 -0400, tom wright wrote: > > I'm not an engineer so I hope I'm using the correct terminology here. I > > have a recorded waveform that I want to apply low and high pass filters > > too, are tehre already R functions existing to do this or am I going to > > have to program my own? > > thanks for any pointers > > tom > > > Thanks for the answers to this, after a little reading I realised that > what sounded so simple wasnt quite. However chapters 15-18 of > http://www.dspguide.com has been very useful. Maybe you need a more specialized tool, such as FFTW? I found it by searching on "fourier" at www.freshmeat.net. Just an idea... -- Jean-Luc ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html