I need to Fourier-analyse some distribution. Is there a way to perform a FFT in root?
I saw some discussion about that dated 1999/2000. Is there any news since that time?

thanks in advance,


Dear Marco

The statistical software “R” contains the functions fft and density, see:
stat.ethz.ch/R-manual/R-patched/ … l/fft.html
stat.ethz.ch/R-manual/R-patched/ … nsity.html

Since I needed the function density in my own root application , I have
converted the corresponding code to C++ in my own class TStat.

The enclosed macro “macroDensity.C” contains the necessary methods
FFT, IFFT and Density. You can do:

.L macroDensity.C

I hope the methods FFT and IFFT are useful for you.
(I have compared my method Density with the R function density, they
give exact the same values.)

BTW, if the root developers are interested to put these methods in class
TMath, they are welcome.

Best regards
macroDensity.C (19.7 KB)