#include <TLegend.h>
#include "TAxis.h"
#include <TF1.h>
#include <TCanvas.h>
#include <TFile.h>
#include <TH1.h>
#include <TGraph.h>
#include <TMath.h>
#include <TF1Convolution.h>
#include <TVirtualFFT.h>
#include "TROOT.h"

void analytical_fit() {
	Double_t D_t_cm=237.*1e-4;//cm/sqrt(cm)
	Double_t L_drift = 30.;//cm
	Double_t v_drift=7.9*1e3;//cm/ns

	Double_t D_l_cm = 290.*1e-4;//cm/sqrt(cm)
	
	Double_t D_l=D_l_cm*D_l_cm*v_drift/2;//cm2/ns

	Double_t sigma_in=TMath::Sqrt(L_drift*L_drift/D_l);//;D_l*D_l*L_drift
	
	double tmax = 511*80;

	
	TF1* tf1_A = new TF1("tf1_A", "[2]*(x>[0])*TMath::Exp(-1*(x>[0])*(x-[0])*3/[1])*TMath::Power((x>[0])*(x-[0])/[1],3)*TMath::Sin((x>[0])*(x-[0])/[1])", 0, tmax);
	tf1_A->SetParameter(0, 9000.);
	tf1_A->SetParameter(1, 600.);
	tf1_A->SetParameter(2,1);

	TF1* tf1_L = new TF1("tf1_L", "gaus(0)", 0, tmax);
	tf1_L->SetParameter(0, 1);
	tf1_L->SetParameter(1, 9000);
	tf1_L->SetParameter(2, sigma_in);

	TF1Convolution* tf1conv_AL = new TF1Convolution("tf1_L", "tf1_A", -1*tmax, tmax, true);
	tf1conv_AL->SetNofPointsFFT(10000);
	TF1   *f = new TF1("f",*tf1conv_AL, 0.01, tmax, tf1conv_AL->GetNpar());
	f->SetParameters(9000, 600, 1, 1, 0, sigma_in);

	TCanvas* c_tf = new TCanvas();
    //tf1_A->Draw();
    //tf1_L->Draw("same");
	f->Draw();
}