void test()
{
  TFile *f = new TFile("hist.root");
  TH1D *h = f->Get("gSpecOut");

  printPeakPositions(h);

  return;
}
void printPeakPositions(TH1 *h)
{
  //make TSpectrum with max 40 peaks
  //NOTE: the second parameter is unused but it's supposed to represent the
  //peak resolution (for separating adjacent peaks, or something)
  TSpectrum *ts = new TSpectrum(40,1);

  //search for the peaks
  Int_t n = ts->Search(h,2,"",.004);
  cout << n << " peaks found. " << endl;
  cout << endl;

  //print the x positions
  Double_t *peakx = ts->GetPositionX();
  for(int i=0;i<n;i++)
    cout << "Peak " << i+1 << ": " << peakx[i] << endl;

  return;
}