How can I use TFFTReal?

Roofit and RooStats
1

Hi everyone,

I’m currently trying to use TFFTReal for data processing. My data in held in Double_t *input samples and I included “TFFTReal.h” in my file.
I tried several declarations, or ways of creating a TFFTReal instance but I always get errors when compiling.

Here are 2 examples :

  1. If I try this :
  TFFTReal fft;
  fft.TFFTReal(n,kFALSE);
  fft.Init("EX",+1,kind);
  fft.SetPoints(input);
  fft.Transform();
  fft.GetPoints(output);

I get : error: invalid use of ‘class TFFTReal’ for the first line.

  1. If I try this :
  TFFTReal fft = new TFFTReal(n,kFALSE);
  fft.Init("EX",+1,kind);
  fft.SetPoints(input);
  fft.Transform();
  fft.GetPoints(output);

I get :
error: invalid conversion from ‘TFFTReal*’ to 'Int_t’
error: initializing argument 1 of 'TFFTReal::TFFTReal(Int_t, Bool_t)'
also for the first line…

Could anyone give me a hint on what I’m missing (I guess I missed something stupid but I can’t find it…) ?

Best regards,
Sylvain Vayre.

2

Either … TFFTReal fft(n, kFALSE); fft.Init("EX", +1, kind); fft.SetPoints(input); fft.Transform(); fft.GetPoints(output); … or … TFFTReal *fft = new TFFTReal(n, kFALSE); fft->Init("EX", +1, kind); fft->SetPoints(input); fft->Transform(); fft->GetPoints(output); delete fft;

3

Ok.

So with the first solution, I still get errors :

qdc.c:(.text+0x752): undefined reference to `TFFTReal::TFFTReal(int, bool)'
qdc.c:(.text+0x769): undefined reference to `TFFTReal::Init(char const*, int, int const*)'
qdc.c:(.text+0x776): undefined reference to `TFFTReal::SetPoints(double const*)'
qdc.c:(.text+0x77f): undefined reference to `TFFTReal::Transform()'
qdc.c:(.text+0x791): undefined reference to `TFFTReal::GetPoints(double*, bool) const'
qdc.c:(.text+0x79a): undefined reference to `TFFTReal::~TFFTReal()'
qdc.c:(.text+0x7b3): undefined reference to `TFFTReal::~TFFTReal()'
collect2: ld returned 1 exit status

And with the second solution, I get one error :

qdc.c:(.text+0x75d): undefined reference to `TFFTReal::TFFTReal(int, bool)'
collect2: ld returned 1 exit status

I guess, there’s something missing here…
Thanks anyway !
Sylvain.

4

Looks like the linker is missing the libFFTW. To your linking command, try to add something like: `root-config --glibs` -lFFTW

5

That was it ! Thank you very much !

Sylvain.