/** University College London Dept of Physics Course in OO 3C59 
| all rights reserved 2000
|
| Main class to run the Compton experiment Monte-Carlo program
|
|
| Author: P.Clarke 
*/

import java.io.* ;
import java.util.*;

public class ComptonMonteCarlo
{

   // Main method where program starts

   public static void main( String[] args)
   {


    // .................................................
    // Set some fixed numbers

    double distance = 50.0 ;        // distance of pmts from rod
    double incidentEnergy = 662.0 ; // Energy of source photons on rod
    double resolution     = 80.0  ; // Detector resolution in keV

    int numberOfEvents = 10000 ;     // Number of photons to generate

    // Ask for some input


    double electronMass ;
    double windowWidth ;

    DataInputStream keyboard = new DataInputStream( System.in );

    System.out.println( " Please input the electron mass in keV ") ;
    try{
        electronMass = Double.valueOf( keyboard.readLine() ).doubleValue();
 //     inputVal = keyboard.readDouble() ;
    }
	catch( IOException e )
	{
      System.out.println( " IOExeption caught for electron mass ") ;
	  electronMass = 0.;
	}


    System.out.println( " Please input the width of the pmt window in cm  ");
	try{
      windowWidth = Double.valueOf( keyboard.readLine() ).doubleValue();
//      windowWidth = keyboard.readDouble() ;
	}
	catch( IOException e )
	{
      System.out.println( " IOExeption caught for window width ") ;
	  windowWidth = 0.;
	}

    System.out.println( " You input "+electronMass+"  and  "+windowWidth ) ;

    //electronMass = 500. ;
	//windowWidth = 5. ;

    // Create a Rod
    Rod myRod = new Rod( incidentEnergy, electronMass ) ;

    // Create a vector of 18 photomultipliers at 10 degree difference from 0-180
    Collection detectors = new Vector();
    for( double ang=0.; ang < 190.; ang+=10. ) 
    {
       detectors.add( new PhotoMultiplier( ang, distance, windowWidth, resolution ) );
    }

    // .............................................
    // Now run the experiment for many photons

    for( int ind=0; ind < numberOfEvents ; ++ind ) 
    {
      // Create a new random photon
      Photon p = myRod.generatePhoton() ;

      // Offer it to each photomultiplier in turn
      Iterator pmt = detectors.iterator() ;

      while( pmt.hasNext() )
      {
        ((PhotoMultiplier) pmt.next()).tryit( p ) ;
      }

	  //System.out.print( " New Photon created with angle "+p.angle()+"\n" ) ;

    }

    // ...........................................
    // Finally output the results by asking each pmt in turn for its average energy

    //std::ofstream outfile( "mcCompton.dat" ) ;

    // Output
    Iterator pmt = detectors.iterator() ;

    while( pmt.hasNext() )
    {
	  PhotoMultiplier p = (PhotoMultiplier) pmt.next() ;

      System.out.println( 
          p.angle()+" "+p.averageEnergy()+" "+resolution+" \n" );
    }

   
    //outfile << detectors[pmt].angle() << "  " 
       //     << detectors[pmt].averageEnergy() << "  "
         //   << resolution
           // << std::endl ;



    // Thats it 

  }

}