Error in <TVirtualFFT::FFT>: plugin not found. (for pyRoot)

[Ufuk_Tok]

ROOT Version: v6.24/08
Platform: lxplus7
Compiler: python 2.7.5

Dear Root experts,

I am trying to use the FFT functions to check the magnitude of the noise from the signal cables using a simple python code.

I have checked the previous reports on the forum with similar issues and checked a couple of things that might help you to find the issue.

Firstly, I checked if I have the fftw3 by this command-line;

root-config --has-fftw3

and gives ‘yes’.

Then I checked the features,

root-config --features

which showed the fftw3 on the prompt.

Then I checked my /usr/include/ folder and confirmed that I have the fftw3.h and other related files in there.

I tried to include the libraries and header file like this in my code:

import ROOT
import cppyy

# Include the fftw3.h header file
cppy.include("fftw3.h")
# Load the FFTW library
ROOT.gSystem.Load("libfftw3")
.
.
.

I still got the error:

Error in TVirtualFFT::FFT: plugin not found

Is there a way to use the FFT in pyRoot?

Thanks in advance!

[Danilo]

Hi,

I am sorry you experience this issue.

How are you using these functions in PyROOT? Could you share a reproducer?

Cheers,
Danilo

[Ufuk_Tok]

Hi Danilo,

Thanks for your prompt answer.

I put the ‘reduced’ code file here.
CSVtoROOT_PLUS_cableNoise.py (2.0 KB)

Thanks in advance,
Ufuk

[Danilo]

Dear Ufuk,

Thanks for the code. I think some input file is needed: can the behaviour be reproduced without it?

Best,
D

[Ufuk_Tok]

Dear Danilo,

Yes, to be able to run the code you will need a csv file.

You can copy and save the random data below in csv format and can repeat the error:

second,Volt
-10.00000E-06,+30.12552392E-03
-9.99000E-06,+32.80334827E-03
-9.98000E-06,+35.19426286E-03
-9.97000E-06,+36.62881162E-03
-9.96000E-06,+37.01135796E-03
-9.95000E-06,+38.73281647E-03
-9.94000E-06,+39.59354572E-03
-9.93000E-06,+41.50627740E-03
-9.92000E-06,+41.50627740E-03
-9.91000E-06,+43.32337249E-03
-9.90000E-06,+41.50627740E-03
-9.89000E-06,+43.03646274E-03
-9.88000E-06,+43.41900907E-03
-9.87000E-06,+43.70591883E-03
-9.86000E-06,+44.18410175E-03
-9.85000E-06,+43.70591883E-03
-9.84000E-06,+44.18410175E-03
-9.83000E-06,+43.70591883E-03
-9.82000E-06,+44.66228466E-03
-9.81000E-06,+44.85355783E-03
-9.80000E-06,+45.23610417E-03

Bests,
Ufuk

[Danilo]

Dear Ufuk,

I can see fftw correctly loaded both on lxplus9 and lxplus7.

#lxplus7
>>> import ROOT
>>> ROOT.gSystem.Load("libfftw3")
>>> ROOT.gSystem.GetLibraries("/usr/lib64/libfftw*")
'/usr/lib64/libfftw3.so.3.3.2'

Cheers,
D

[Ufuk_Tok]

Dear Danilo,

Thank you. I checked that I also have the same libraries on lxplus7. Then what else might be the cause of the error?

Bests,
Ufuk

[Danilo]

Hi,

I am not sure. I would start removing slice by slice pieces of the example until something is found.

Cheers,
D