Sum over entries in Branch and indices of entries satisfying a given condition

[bdela]

Hello,

I am trying to write a concise if condition in ROOT, the analogue of the python line

if sum(muon)>=2 and sum(charge[np.where(muon==1)])==0: #at least one muon track and sum of charges of muon tracks = 0

i.e. I would like to select all the events with at leat two muon tracks and the sum of the muon charges to be zero. I know that the Scan method is useful for this, but I it not quite what I need for my if condition.

Can anyone suggest how to do this, and in general how manipulate indices as above in python arrays?

Thanks,

-B

[ganis]

Hello,

See replay to the other post.
Can you specify what are the types of ‘muon’ and ‘charge’ and how they appear in your tree (branch name, …)?

G Ganis

[bdela]

Hello,

Thank you for your advice. I attach below a snippet of the mymacro.h I obtained via the method of MakeClass, following the tutorial.

// Header file for the classes stored in the TTree if any.

class mymacro {
public :
   TTree          *fChain;   //!pointer to the analyzed TTree or TChain
   Int_t           fCurrent; //!current Tree number in a TChain

// Fixed size dimensions of array or collections stored in the TTree if any.

   // Declaration of leaf types
   Int_t           run;
   Int_t           evt;
   Int_t           bunchid;
   Int_t           bunchtype;
   Int_t           trighlt1;
   Int_t           trigmu;
   Int_t           l0dim;
   Int_t           l0m;
   Int_t           stripphi;
   Int_t           nlong;
   Int_t           nvelo;
   Int_t           down;
   Int_t           ntk;
   Int_t           nspd;
   Int_t           ntotphot;
   Int_t           nout;
   Int_t           nphotons;
   Float_t         etprev1;
   Float_t         etprev2;
   Int_t           tt[10];   //[nout]
   Float_t         tx[10];   //[nout]
   Float_t         ty[10];   //[nout]
   Float_t         tz[10];   //[nout]
   Float_t         px[10];   //[nout]
   Float_t         py[10];   //[nout]
   Float_t         pz[10];   //[nout]
   Float_t         pt[10];   //[nout]
   Int_t           charge[10];   //[nout]
   Int_t           muon[10];   //[nout]
   Int_t           muacc[10];   //[nout]
   Float_t         pide[10];   //[nout]
   Float_t         pidk[10];   //[nout]
   Float_t         pidpi[10];   //[nout]
   Float_t         pidp[10];   //[nout]
   Float_t         pidm[10];   //[nout]
   Float_t         ecal[10];   //[nout]
   Float_t         hcal[10];   //[nout]
   Float_t         eoverp[10];   //[nout]
   Float_t         phx[6];   //[nphotons]
   Float_t         phy[6];   //[nphotons]
   Float_t         phz[6];   //[nphotons]
   Int_t           spd[6];   //[nphotons]
   Int_t           prs[6];   //[nphotons]
   Int_t           nl0;
   Float_t         l0et[3];   //[nl0]
   Float_t         l0phi[3];   //[nl0]
   Float_t         l0theta[3];   //[nl0]
   Int_t           nher;
   Int_t           herchan[30];   //[nher]
   Int_t           heradc[30];   //[nher]

   // List of branches
   TBranch        *b_run;   //!
   TBranch        *b_evt;   //!
   TBranch        *b_bunchid;   //!
   TBranch        *b_bunchtype;   //!
   TBranch        *b_trighlt1;   //!
   TBranch        *b_trigmu;   //!
   TBranch        *b_l0dim;   //!
   TBranch        *b_l0m;   //!
   TBranch        *b_stripphi;   //!
   TBranch        *b_nlong;   //!
   TBranch        *b_nvelo;   //!
   TBranch        *b_ndown;   //!
   TBranch        *b_ntk;   //!
   TBranch        *b_nspd;   //!
   TBranch        *b_ntotphot;   //!
   TBranch        *b_nout;   //!
   TBranch        *b_nphotons;   //!
   TBranch        *b_etprev1;   //!
   TBranch        *b_etprev2;   //!
   TBranch        *b_tt;   //!
   TBranch        *b_tx;   //!
   TBranch        *b_ty;   //!
   TBranch        *b_tz;   //!
   TBranch        *b_px;   //!
   TBranch        *b_py;   //!
   TBranch        *b_pz;   //!
   TBranch        *b_pt;   //!
   TBranch        *b_charge;   //!
   TBranch        *b_muon;   //!
   TBranch        *b_muacc;   //!
   TBranch        *b_pide;   //!
   TBranch        *b_pidk;   //!
   TBranch        *b_pidpi;   //!
   TBranch        *b_pidp;   //!
   TBranch        *b_pidm;   //!
   TBranch        *b_ecal;   //!
   TBranch        *b_hcal;   //!
   TBranch        *b_eoverp;   //!
   TBranch        *b_phx;   //!
   TBranch        *b_phy;   //!
   TBranch        *b_phz;   //!
   TBranch        *b_spd;   //!
   TBranch        *b_prs;   //!
   TBranch        *b_nl0;   //!
   TBranch        *b_l0et;   //!
   TBranch        *b_l0phi;   //!
   TBranch        *b_l0theta;   //!
   TBranch        *b_nher;   //!
   TBranch        *b_herchan;   //!
   TBranch        *b_heradc;   //!

In this case I am considering the branches muon and charge, such that

  Int_t           charge[10];   //[nout]
  Int_t           muon[10];   //[nout]

Thanks again,

B

[ganis]

Hello,

From your tree definition it looks that the number of muons is ‘nout’.
So this should plot the sum of charges or at least 2 muons:

tree->Draw("Sum$(charge)", "nout>=2")

and this select those with total charge null:

tree->Scan(..., "nout>=2 && Sum$(charge)==0")

G Ganis

[bdela]

Hello,

nout is the number of tracks per event, not necessarily the number of muon tracks. These are a subset of nout such that muon==1.

However, your advice is still quite helpful. Thank you.