root example

cpp

#include "TRandom3.h"
#include "TH1F.h"							//INCLUDE ROOT HEADER FILES
#include "TLorentzVector.h"					// WE WILL USE
#include "TCanvas.h"

double v1px, v1e;           				//DECLARE VECTOR COMPONENTS
double  v2pz, v2e;

void TLV()
{
	TCanvas* c1 = new TCanvas("table", "TLVs", 800,800 );
	TH1F* histoM = new TH1F("masses","Lorentz Vectors' Masses",600,0,20.);
	TH1F* histoPt = new TH1F("pts","Lorentz PTs", 600,-0.5 , 7.);
	TRandom3* uret = new TRandom3();        // - RANDOM GENERATOR
	uret->SetSeed(855);                    	//   SEED
	TLorentzVector v1;					   	// - DECLARING LORENTZ
    TLorentzVector v2;					  	//   VECTORS
    TPad *pad1 = new TPad("pad1", "pad1", 0, 0.5, 1, 1.0);
    TPad *pad2 = new TPad("pad2", "pad2", 0, 0.05, 1, 0.5);
	for (int j=0;j<100;j++){
			        			//MAKING RANDOM VECTORS VARIABLES
				v1px =abs(uret->Gaus(2,1));			
				v1e =abs(uret->Gaus(6,1));					
								//MAKING RANDOM ANOTHER VECTORS VARIABLES
				v2pz =abs(uret->Gaus(2,1));
				v2e =abs(uret->Gaus(6,1));					 
		v1.SetPxPyPzE(v1px,1,1,v1e);  	//SET THE COMPONENTS VECTOR1
		v2.SetPxPyPzE(1,1,v2pz,v2e);	//SET THE COMPONENTS VECTOR2
		TLorentzVector v3 = v1 + v2;	//SUMMATION TWO LORENTZ VECTORS
		double tb2 = v3.Pt();			//SET THE PT VALUE OF NEW VECTOR
		double tb1 = v3.M();			//SET THE MASS OF NEW VECTOR
		
		histoPt->Fill(tb2);				//INSERT VALUES TO HISTOGRAMS
		histoM->Fill(tb1);
	};
	pad1->Draw();
	pad1->cd();
	histoPt->Draw();				//DRAWING TWO HISTOGRAM IN 
	c1->cd();						//ONE CANVAR HELPS WITH PAD
	pad2->Draw();
	pad2->cd();
	histoM->Draw();
	c1->SaveAs("cikti.pdf");		//SAVE THE CANVAS AS PDF FILE
}
/*------------------------- END OF FUNCTION ----------------------------*/

int main() { TLV(); }				//MAIN FUNCTION OF SCRIPT

/*------------------------- END OF SCRIPT ------------------------------*/