Add single cluster event selection to the calibration of HMS

calorimeter.

CALIBRATION/hms_cal_calib/THcShowerCalib.h

@@ -106,6 +106,8 @@ class THcShowerCalib {
   Double_t        H_cer_npe[2];
   Double_t        H_tr_beta;
 
+  Double_t        H_cal_nclust;
+
   TBranch* b_H_cal_1pr_aneg_p;
   TBranch* b_H_cal_1pr_apos_p;
 
@@ -130,6 +132,8 @@ class THcShowerCalib {
   TBranch* b_H_cer_npe;
   TBranch* b_H_tr_beta;
 
+  TBranch* b_H_cal_nclust;
+
   // Quantities for calculations of the calibration constants.
 
   Double_t fe0;
@@ -240,6 +244,8 @@ fTree->SetBranchAddress("H.tr.tg_dp", &H_tr_tg_dp,&b_H_tr_tg_dp);
 fTree->SetBranchAddress("H.cer.npe", H_cer_npe,&b_H_cer_npe);
 fTree->SetBranchAddress("H.tr.beta", &H_tr_beta,&b_H_tr_beta);
 
+fTree->SetBranchAddress("H.cal.nclust", &H_cal_nclust,&b_H_cal_nclust);
+
   // Histogram declarations.
 
   hEunc = new TH1F("hEunc", "Edep/P uncalibrated", 500, 0., 5.);
@@ -413,6 +419,8 @@ TBranch ("H.tr.beta", &H_tr_beta);
 
   if (H_tr_n != 1) return 0;
 
+  if (H_cal_nclust != 1) return 0;
+
   bool good_trk =   H_tr_tg_dp > DELTA_MIN &&
 		    H_tr_tg_dp < DELTA_MAX &&
 		    H_tr_x + H_tr_xp*D_CALO_FP > XMIN &&