void gainuni(Char_t *chamberi = "1958"){

   gROOT->Reset();

   int chamber = 1955;
   int logy = 0;

   // sql connection
   const char *dba = "oracle://orarac.gsi.de:1521/db-alice-test";
   TSQLServer *db=TSQLServer::Connect(dba,"alis_app","dbalice");
   
   if(chamberi[0]=='0'||chamberi[0]=='1'||chamberi[0]=='2'||chamberi[0]=='3'||chamberi[0]=='4'||chamberi[0]=='5'||chamberi[0]=='6'||chamberi[0]=='7'||chamberi[0]=='8'||chamberi[0]=='9'){
      chamber = atoi(chamberi);
   }
   else{
      const char *ff3 = "DETECTOR_CODE, COMPONENT_ID, TYPE_CODE, LOCAL_ID";
      Char_t sql3[200] = "";
      sprintf(sql3, "SELECT component_id FROM components WHERE detector_code='TRD' AND type_code='ROC' AND local_id='%s'", chamberi);
   
      TSQLResult *res3 = db->Query(Form(sql3, ff3));
      int result = res3->GetRowCount();
      TSQLRow * row3 = 0;
      row3 = res3->Next();
      if(result > 0){
         chamber = atoi(row3->GetField(0));
      }
      else{
         chamber = 0;
         cout << "Can't find " << chamberi << " in database" << endl;
         break;
      }
      delete row3;
      delete res3;
   }
   gStyle->SetPadGridY(1);
   gStyle->SetPadGridX(1);
   gStyle->SetPalette(1);
   int Ab = GetNCol(db, "GAINUNI");
   Char_t sqlb[200] = "";
   sprintf(sqlb, "SELECT * FROM process_values WHERE component_id=%d AND  process_code='%s'", chamber, "GAINUNI");
   TSQLResult *resb = db->Query(sqlb);
   int Nb = resb->GetFieldCount();
   int Rb = resb->GetRowCount()/Ab;
   TSQLRow * rowb = 0;
   
   double *xb = new double[Rb];
   double *yb = new double[Rb];
   double *xc = new double[Rb];
   double *yc = new double[Rb];
   double *zc = new double[Rb];

   double average = 0;
   double max = 0;
   double min = 10000;

   int counter = 0;
   int counter1 = 0;
   int counter2 = 0;
   int counter3 = 0;
   int counter4 = 0;

   while((rowb = resb->Next())) {
      double rb = atof(rowb->GetField(6)); //konvertiert einen String in ein int
      int cb = atoi(rowb->GetField(5));
      double vb = atof(rowb->GetField(7));
      if(cb == 1){
         if(vb != 0){
            xc[counter1] = vb;
            counter1++;
         }
      }
      if(cb == 2){
         if(vb != 0){
            yc[counter2] = vb;
            counter2++;
         }
      }
      if(cb == 3){
         if(vb != 0){
            zc[counter3] = vb;
            average = average + zc[counter3];
            if(zc[counter3] > max){
               max = zc[counter3];
            }
            if(zc[counter3] < min){
               min = zc[counter3];
            }
            counter3++;
         }
         if(vb == 0){
            counter4++;
         }
      }

      if (cb == 5){
         xb[counter] = rb;
         yb[counter] = vb;
         counter++;
      }
   }
   delete resb;
   delete rowb;

   average = average/counter3;

   /*************** Berechnung der Stansardabweichung *********************************/

   double sigma = 0;
   counter3 = 0;

   for(counter3 = 0; counter3 < 100; counter3++){
      sigma = sigma + pow((zc[counter3] - average),2);
   }

   sigma = sigma/(counter3-1);

   // Ausgabe
   cout<<"average: "<<average<<"mA"<< endl;
   cout<<"standard deviation: "<<sigma<<"mA"<< endl;
   
   /*************** Berechnung der maximalen Abweichung *******************************/

   double maxpro;

   if(max - average < average - min){
      max = average - min;
   }
   else{
      max = max - average;
   }
   maxpro = max*100/average;
   cout<<"max. deviation: "<<max<<"mA"<< endl;
   cout<<"relative: "<<maxpro<<"%"<< endl;

   /***********************************************************************************/

   const char *ff6 = "DETECTOR_CODE, COMPONENT_ID, TYPE_CODE, LOCAL_ID";
   Char_t sql6[200] = "";
   sprintf(sql6, "SELECT local_id FROM components WHERE detector_code='TRD' AND type_code='ROC' AND component_id=%d", chamber);

   TSQLResult *res6 = db -> Query(Form(sql6, ff6));
   TSQLRow *row6 = 0;
   row6 = res6 -> Next();
   Char_t local1[100] = row6 -> GetField(0);
   delete row6;
   delete res6;

   /***********************************************************************************/

   TCanvas *c3 = new TCanvas("c3","Gain Uniformity 2D");

   // c3 -> Divide(2);
   // c3 -> cd(1);
   
   TGraph2D *gra = new TGraph2D(Rb-counter4, xc, yc, zc);
   
   c3 -> SetLogy(logy);
   c3 -> SetFillColor(0);        // weisser Hintergrund
   c3 -> SetFrameBorderMode(0);
   
   gra -> SetMarkerStyle(20);
   
   Char_t title5[100];
   sprintf(title5, "Gain Uniformity 2D, local_id='%s'", local1);
   gra -> SetTitle(title5);
   gra -> GetXaxis() -> SetTitle("z-Axis(cm)");
   gra -> GetYaxis() -> SetTitle("phi-Axis(cm)");
   gra -> GetZaxis() -> SetTitle("current(mA)");
   gra -> GetXaxis() -> SetTitleOffset(1.8);
   gra -> GetYaxis() -> SetTitleOffset(1.8);
   gra -> GetZaxis() -> SetTitleOffset(1.2);
   gra -> GetXaxis() -> CenterTitle();
   // TLegend *myLegend = new TLegend(0.17,0.68,0.32,0.8);
   // myLegend -> AddEntry(gra,"Graph 1","P");
   // myLegend -> AddEntry(gra,"Graph 2","P");
   // myLegend -> AddEntry(gra,"Graph 3","P");
   // myLegend -> Draw();
   gra -> Draw("surf1Z");
   
   /***********************************************************************************/

   TCanvas *c2 = new TCanvas("c2","Gain Uniformity 1D");
   // c3 -> cd(2);
   
   TGraph *grb = new TGraph(Rb, xb, yb);

   c2 -> SetLogy(logy);
   c2 -> SetFillColor(0);        // weisser Hintergrund
   c2 -> SetFrameBorderMode(0);

   grb -> SetMarkerStyle(20);

   Char_t title4[100];
   sprintf(title4, "Gain Uniformity 1D, local_id='%s'", local1);
   grb -> SetTitle(title4);
   grb -> GetXaxis() -> SetTitle("z-Axis(cm)");
   grb -> GetYaxis() -> SetTitle("current(mA)");

   grb -> Draw("ALP");

   delete[] xc;
   delete[] yc;
   delete[] zc;
   delete[] xb;
   delete[] yb;

   db->Close();
}

Char_t GetLocal(TSQLServer *db, int chamber){
  const char *ff4 = "DETECTOR_CODE, COMPONENT_ID, TYPE_CODE, LOCAL_ID";
  Char_t sql4[100];
  sprintf(sql4, "SELECT local_id FROM components WHERE detector_code='TRD' AND type_code='ROC' AND component_id=%d", chamber);

  TSQLResult *res4 = db->Query(Form(sql4, ff4));
  TSQLRow * row4 = 0;
  row4 = res4->Next();
  Char_t local[100] = row4->GetField(0);
  delete row4;
  delete res4;
  cout<<endl<<local<<endl;
  return local;
}

int GetNCol(TSQLServer *db, const char *process){
  const char *sql = "SELECT count(*) from DEFINITIONS_OF_VT_COLUMNS where process_code='%s'";

  TSQLResult *res = db->Query(Form(sql, process));
  TSQLRow *row = res->Next();
  int v = atoi(row->GetField(0));

  delete res;
  delete row;

  return v;
}