[Frost] root Trees

[Brian Morrison]

Hey All,

Just wondering if anyone has any experience working with ROOT Trees.  I'm
currently trying to make a branch for the GPID bank and fill it with
arrays of each of the bank values for each event (as shown below):

typedef struct{
  int   gpidN;
  int   pid[MAX_PARTICLES];
  float x[MAX_PARTICLES];
  float y[MAX_PARTICLES];
  float z[MAX_PARTICLES];
.
.
.
  int   Ngrf[MAX_PARTICLES];
} Ngpid_t;

	static Ngpid_t Ngpid;
	TTree *gpid_tree = new TTree("T","test");
gpid_tree->Branch("Ngpid",&Ngpid,"gpidN/i:pid/i:x/F:y/F:...Ngrf/i");


(in the event loop now)
	Ngpid.gpidN = GPID_NH;
	for(int n=0;n<GPID_NH;n++){
		Ngpid.pid[n] = GPID[n].pid;
		Ngpid.x[n] =GPID[n].x;
.
.
.
		Ngpid.Ngrf[n] = GPID[n].ngrf;
	}

	gpid_tree->Fill();