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Cebaf's Meson Spectrometer for HallD

MCFast consists of a set of modularized Monte Carlo library routines.  The 
package is designed to perform parameterized tracking by assembling a 
covariance matrix that represents all of the materials and measurement planes 
traversed by a generated particle.  A reconstructed track is produced by 
smearing the generated track parameters according to the track's covariance 
matrix.

The HallD version of MCFast requires the following fermi lab products(these 
are precompiled libraries. Future plans include placing the source files in 
the halld CVS repository. Currently there is no support for a MCFast version 
for Linux) A distributions of these products can be obtained via ftp from 
ftp.fnal.gov (username:ftp).  The site is restricted  to registered users. A 
registration form can be obtained in the top level directory at the  site.

Caution! Some of these packages are currently in development, so using another
 version of any product where a specific version is listed may break mcfast.

        stdhep v3_04
        qq v9_2
	mcfast v2_6_2

The above packages support only the following platforms: 
	OSF1, HP-UX,IRIX, IRIX64, SunOS, Ultrix, Aix, Linux(except for mcfast)

****************************************
*	FIVE EASY STEPS TO USE MCFAST  *
****************************************

[1]	Get the Packages: stdhepv3_04, qqv9_2, mcfastv2_6_2
	from fermi lab; and HDMS_mcfast & stdhep_translators
	from the HallD CVS repository.


	Update the env's for your local system by
	modifying and adding these lines to your .cshrc file
	and source it. 

	# The first 2 packages can be obtained from the Halld CVS repository
	setenv HDMS_MCFAST_DIR /dsk19/halld/source/HDMS_mcfast
	setenv STDHEP_TRANS_DIR /dsk19/halld/source/stdhep_translators

	# below are fermi lab products (See above about fermi lab products)
	setenv MCFAST_DIR /dsk19/halld/source/mcfast
	setenv STDHEP_DIR /dsk19/halld/source/stdhep
	setenv QQ_DIR /dsk19/halld/source/qq
	source $HDMS_MCFAST_DIR/setup
	source $STDHEP_DIR/ups/setup.csh
	source $QQ_DIR/ups/setup.csh

[2]
	Add a symbolic link.
		ln -s  $MCFAST_DIR/mcfast/db  $HDMS_MCFAST_DIR/db
		# This is NEEDED to run mcfast everytime!
[3]
	Make the StdHep translators.
		cd  $STDHEP_TRANS_DIR
		make all
[4]
	Make MCFast
		cd $HDMS_MCFAST_DIR
		make mcfast

[5]	Running MCFast
	
	Generate some MC data using genr8( or any program that 
	writes esr itape output --GROUP=802 or genr8 ascii format)
	
	Translate MC files to StdHep format using either itape2stdhep 
	or ascii2stdhep ( itape2stdhep -i<input.itape> -o<output.evt> 
	-N<#events> -n<#of particles> )

	Run mcfast.
		mcfast [-f HDMS.cmd] [-l lpt_file] [-hb Hbook_file]

	where  	HDMS.cmd is the ascii command file that drives mcfast 
       		lpt_file     = name of ASCII output run time log file
       		Hbook_file   = name of output Hbook file

	o The StdHep output file can be converted back to itape or ascii
	using either stdhep2itape or stdhep2ascii
	
	o The hbook file will contain 4 histograms which  represents
	the differences of the four-momentum components between the 
	generated and smeared tracks.

	o In summary, 4 files are needed to run mcfast:
		(1) "dd" a link to $MCFAST_DIR/mcfast/dd
		(2) "HDMS_v_1.0.db" the detector geo file
		(3)  "HDMS.cmd" the ascii command file
		(4) the evt (stdhep) file named in HDMS.cmd
	
		HDMS_v_1.0.db and HDMS.db are located in 
		the $HDMS_MCFAST_DIR