ROOT+Geant4

Roofit and RooStats
1

so I have this code which outputs a macro file for geant4
I want it to generate different particles where 90% are pions and the rest(10 %) are kaons

#include <iostream> 
#include "TMath.h"
#include <fstream> 
#include <cmath>
#include <sstream>
#include <stdio.h>
#include "TRandom3.h"
#include "TF2.h"


using namespace std;

void main(int argc, char** argv) 
{ 
	
	//Written to give out new TORCH macros with correct event and run ID. 

	//Assume only one runID. 

	int N_particles = 1000; 

	//relevant settings

	ostringstream output_file_name;
	output_file_name << "modular_x=0_y=-575.in";
	freopen (output_file_name.str().c_str(),"w",stdout);

	double pos_start_x = 0.;
	double pos_start_y = -575.; 
	double theta_t = 5./(180/TMath::Pi()); 

	//end of settings

	double direction_x = 0.; 
	double direction_y = sin(theta_t);
	double direction_z = cos(theta_t); 

	cout << "/control/verbose 0" << endl; 
	cout << "/tracking/verbose 0" << endl; 
	cout << "/event/verbose 0" << endl; 
	cout << "/run/verbose 0 " << endl; 

	cout << "/gun/particle proton" << endl; 
	cout << "/gun/energy 180 GeV" << endl; 
	cout << "/mysetrun/SetRunID 1" << endl; 

	cout << "/gun/direction " << direction_x << " " << direction_y << " " << direction_z << endl; 
	cout << "/gun/position " << pos_start_x << " " << pos_start_y << " -0.00001 mm" << endl; 

	//#5 deg tilt
	//double xt0[3] = {0., 0., 0.}; 
	//double vt0[3] = {0., 0.0871557, 0.99619647};

	//#7.5 deg tilt
	//double xt0[3] = {-30., -13.8, 0.};
	//double vt0[3] = {0., 0.130526, 0.991445};

	
	for(int w=0; w<N_particles; w++)
	{
		cout << "/mysetevent/SetEventID " << w << endl;
		cout << "/run/beamOn 1" << endl; 
		cout << endl; 
	}


	//system("pause"); 

}

so what I did is change the loop to be like this:

[code]
for (int w=0; w<900; w++)

{ cout << "/mysetevent/SetEventID " << w << endl;
cout << “/gun/particle pi+” << endl;
cout << “/run/beamOn 1” << endl;
cout << endl;
}
for (int x=0; x<100; x++)
{
cout << "/mysetevent/SetEventID " << w << endl;
cout << “/gun/particle pi+” << endl;
cout << “/run/beamOn 1” << endl;
cout << endl;
}
[/code]

is that a correct way of doing it ?
and another thing, if I want it to generate random particles, how can I do that?
any comment is appreciated . Thank you.

2

Hi,

this looks like a question for the G4 hypernews.