%%cpp -d
#include "TCanvas.h"
#include "TMath.h"
#include "TH1.h"
#include "TF1.h"
#include "TRandom.h"
#include "TSpectrum.h"
#include "TVirtualFitter.h"


Int_t npeaks = 30;

%%cpp -d
Double_t fpeaks(Double_t *x, Double_t *par) {
   Double_t result = par[0] + par[1]*x[0];
   for (Int_t p=0;p<npeaks;p++) {
      Double_t norm  = par[3*p+2];  "height" or "area"
      Double_t mean  = par[3*p+3];
      Double_t sigma = par[3*p+4];
#if defined(__PEAKS_C_FIT_AREAS__)
      norm /= sigma * (TMath::Sqrt(TMath::TwoPi()));  "area"
#endif /* defined(__PEAKS_C_FIT_AREAS__) */
      result += norm*TMath::Gaus(x[0],mean,sigma);
   }
   return result;
}

Int_t np=10;

npeaks = TMath::Abs(np);
TH1F *h = new TH1F("h","test",500,0,1000);

Double_t par[3000];
par[0] = 0.8;
par[1] = -0.6/1000;
Int_t p;
for (p=0;p<npeaks;p++) {
   par[3*p+2] = 1; // "height"
   par[3*p+3] = 10+gRandom->Rndm()*980; // "mean"
   par[3*p+4] = 3+2*gRandom->Rndm(); // "sigma"
#if defined(__PEAKS_C_FIT_AREAS__)
   par[3*p+2] *= par[3*p+4] * (TMath::Sqrt(TMath::TwoPi())); // "area"
#endif /* defined(__PEAKS_C_FIT_AREAS__) */
}
TF1 *f = new TF1("f",fpeaks,0,1000,2+3*npeaks);
f->SetNpx(1000);
f->SetParameters(par);
TCanvas *c1 = new TCanvas("c1","c1",10,10,1000,900);
c1->Divide(1,2);
c1->cd(1);
h->FillRandom("f",200000);
h->Draw();
TH1F *h2 = (TH1F*)h->Clone("h2");

TSpectrum *s = new TSpectrum(2*npeaks);
Int_t nfound = s->Search(h,2,"",0.10);
printf("Found %d candidate peaks to fit\n",nfound);

TH1 *hb = s->Background(h,20,"same");
if (hb) c1->Update();
if (np <0) return;

c1->cd(2);
TF1 *fline = new TF1("fline","pol1",0,1000);
h->Fit("fline","qn");

par[0] = fline->GetParameter(0);
par[1] = fline->GetParameter(1);
npeaks = 0;
Double_t *xpeaks;
xpeaks = s->GetPositionX();
for (p=0;p<nfound;p++) {
   Double_t xp = xpeaks[p];
   Int_t bin = h->GetXaxis()->FindBin(xp);
   Double_t yp = h->GetBinContent(bin);
   if (yp-TMath::Sqrt(yp) < fline->Eval(xp)) continue;
   par[3*npeaks+2] = yp; // "height"
   par[3*npeaks+3] = xp; // "mean"
   par[3*npeaks+4] = 3; // "sigma"
#if defined(__PEAKS_C_FIT_AREAS__)
   par[3*npeaks+2] *= par[3*npeaks+4] * (TMath::Sqrt(TMath::TwoPi())); // "area"
#endif /* defined(__PEAKS_C_FIT_AREAS__) */
   npeaks++;
}
printf("Found %d useful peaks to fit\n",npeaks);
printf("Now fitting: Be patient\n");
TF1 *fit = new TF1("fit",fpeaks,0,1000,2+3*npeaks);

TVirtualFitter::Fitter(h2,10+3*npeaks);
fit->SetParameters(par);
fit->SetNpx(1000);
h2->Fit("fit");

gROOT->GetListOfCanvases()->Draw()