I had installed fftw3 but I don't find it in features

If I try

root-config --features

I got these:

cxx11 asimage builtin_afterimage builtin_clang builtin_llvm builtin_lz4 builtin_lzma builtin_openssl builtin_pcre builtin_tbb builtin_vdt builtin_xrootd builtin_xxhash builtin_zstd clad dataframe exceptions gdml http imt mlp pyroot roofit runtime_cxxmodules shared ssl tmva tmva-pymva spectrum vdt x11 xrootd

and with “no” if “root-config --has-fftw3”
it’s obvious that I don’t have fftw3.
But if I try:

sudo apt-get install libfftw3-dev

It showed me:

libfftw3-dev is already the newest version (3.3.8-2ubuntu1).

I don’t konw why, how can I add fftw3 to my features?
_ROOT Version:6.22/00
Compiler: C++


Thanks for the post.
You indeed do have libfftw3 on your system, however ROOT seems to have been configured without it. Unfortunately, it is not enough to add it on the system to have all the necessary components in ROOT.
The solution would be to reconfigure and rebuild ROOT, perhaps profiting from a more recent version (6.32.02 is already out, will be announced today).


OK, I will try to rebulid ROOT, another question is that I also need minuit2, but I could’t find it in Dependencies for Ubuntu. Should I use “sudo apt-get install minuit2-dev” or something else?


This is an excellent question - thanks. I add some resources for future reference.
Minuit2 is the default in the 6.32 series (since the 6.30 series): this is also clarified in the build options and Release Notes.
Of course it’s normal not to know everything, hopefully this post will help other users!

In summary, no, nothing to do on your side.



Sorry for my late reply becasue of my cousin’s wedding.
At first time I guess maybe fftw3 and minuuit2 are not default in 6.22. But after I read build options carefully,I found just minuit2 is “OFF”. Whatever, this time I add this:

cmake -Dfftw3=ON -Dminuit2=ON ../root

After reconfigure and rebuild, I indeed got fftw3 and minuit2.
Thanks again!


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