FFT - Fast Fourier Transformation Problem


I have a problem concerning fft.h.
I used the code as shown in the tutorial fft.C and I always get an error:

"Error in TVirtualFFT::FFT handler not found"
Break segmentation violation…

I also could not start the tutorial-script:
When I type ‘root /…path…/root/tutorials/fft/FFT.C’ into the terminal,
I get the same error.

Can somebody help me??

Try “root-config --features” and see if the output contains “fftw3”, or try “root-config --has-fftw3” and see if you get “yes”. If you get “no”, you don’t have FFT support in your ROOT (requires the libfftw3 shared library and its include file when configuring ROOT).
See also http://root.cern.ch/root/html/MATH_FFTW_Index.html and http://root.cern.ch/root/html/TVirtualFFT.html

Thank you!
Then this will be the problem. Indeed, there is no FFT-support in my root. Could you (or someone else) please give a short description on how I can include this? (Sorry, I’am rather new to Root and not really experienced.)
Kind regards,

If you are using any decent Linux, you simply need to install appropriate “binary” and “development” packages which provide libfftw3.
Then, build your ROOT from scratch. After the “configure” step, make sure that the “config.log” file contains “Result: Enabled support for … fftw3, …” somewhere near its end.
Search also for “fftw” in: https://root.cern.ch/build-root-old-method