void analysis(){

    TFile *f =new TFile("pedestal2_2022022.root","READ");
    TTree *tr = (TTree*)f->Get("tree");

    TCanvas *c1 = new TCanvas("c1");
    TCanvas *c2 = new TCanvas("c2");
    TCanvas *c3 = new TCanvas("c3");
    TCanvas *c4 = new TCanvas("c4");

    vector<double> mean ;
    vector<double> std ;
    int entries = tr->GetEntries(); //10000 //row
    cout<<entries<<endl;
    int signal[128];
    //int signal[10000][128];
    tr->SetBranchAddress("signal",signal);
    TF1 * fit = new TF1("fit","gaus",500,600);

    int inv_array[128][10000];

    for (int i=0 ; i<entries; i++){
        tr->GetEntry(i);
        for (int j =0 ;j<128;j++){
            inv_array[j][i] = signal[j];
        }

    }
   TH1F * hist10 = new TH1F("hist10","ADC of Channel 10",20, 490 ,560);
    for (int i =0 ;i< 128; i++){
        TH1F * hist = new TH1F("hist","ADC of Channel 10",100, 480 ,600);
        
        for (int j =0 ; j<10000; j++){
            if (i==9){
                hist10->Fill(inv_array[9][j]);
            }

            hist->Fill(inv_array[i][j]);
        }
        hist->Fit("fit","Q");
        delete hist;
        double pedestal = fit ->GetParameter(1);
        double noise = fit -> GetParameter(2);
        mean.push_back(pedestal);
        std.push_back(noise);
    }
    c1->cd();
    hist10->Draw();
     

    TH1F * hpedestal = new TH1F("hpedestal","Pedestal of 128 channels",128,0, 128);
    TH1F * hnoise = new TH1F("hnoise","Noise of 128 channels",128,0, 128);

    for (int j = 0;  j<128; j++){
        hpedestal->SetBinContent(j, mean[j]);
        hnoise->SetBinContent(j,std[j]);
    }
    c2->cd();
    hpedestal->GetYaxis()->SetRangeUser(400,600);
    hpedestal->SetFillColorAlpha(kBlue, 0.20);
    hpedestal->Draw("B");

    c3->cd();
    hnoise->GetYaxis()->SetRangeUser(5,7);
    hnoise->SetFillColorAlpha(kBlue, 0.20);
    hnoise->Draw("B");

    double common_mode[128];
    common_mode[0] = 0;
    for (int cm = 1; cm <=127; cm++){
        TH1F * tmp = new TH1F("tmp","tmp",25,-25, 25);
        TF1 *fit2 = new TF1("fit2","gaus",-25,25);
        for (int event =0 ; event <10000; event++){
            double cm_noise = (inv_array[cm][event] - mean[cm] ) - (inv_array[cm-1][event] - mean[cm-1] );
            tmp->Fill(cm_noise);
        }
        
        tmp->Fit("fit2","Q");
        delete tmp;
        common_mode[cm] = (fit2->GetParameter(2))/sqrt(2);   
        delete fit2;
    }
   
    TH1F* dNoise = new TH1F("dNoise","dNoise of 128 channels",129,0,129);
    dNoise->SetBinContent(1,common_mode[0]);
    for(int n= 2; n<129; n++){
        dNoise->SetBinContent(n,common_mode[n-1]);
        
    }
    c4->cd();
    dNoise->Draw();
}