FFT problem

Dear all,
I have a problem using the FFT, if I do:

TH1 *hm =0;
hm = hresult->FFT(hm, “MAG”);

I get the hm (hresult is defined previously)

but it is not clear to me is I have hm and I need to do the inverse FFT which flag to put



If you want to do the inverse you need both the real and the imaginary part since you are doing by default a real to complex transformation. You can do this using the option “C2R” with the TVirtualFFT class.
See root.cern.ch/root/htmldoc/TVirtualFFT.html