NAME:
	stat_cl_wfc
 PURPOSE:
       Creates a ps or gif file containing a plot of stat vs core mag,
		objects separated by class:
	Outputs to screen or ps file or gif (or both)
 CALLING SEQUENCE:
	stat_cl_wfc,wfcdb,wfccat[,ps=ps,gif=gif,col=col,field=field]
 INPUTS:
	wfcdb: The wfc database to be used
 	wfcat: catalogue file on which wfcdb is based 
		eg: 'wfc/izrgulockman_*.mer'
 OPTIONAL INPUT KEYWORDS:
	col: STRING! the colour to be used (i,z,r,g,u) default is 'i'
  OPTIONAL OUTPUT PARAMETERS:
	ps: file name of output ps file
	gif:file name of output gif file. Only active if ps is not set
		If neither set the output is sent to an IDL graphics window
	field:name of field (if directory in named after field)
 EXAMPLE:
	stat_cl_wfc,'wfcdb','wfccat',ps='stat.ps',col='i',field='field']
 CALLED PROCEDURES:
	astrolib procedures,select_classes,avoid_offplot,select_cond
	ogif,cgif,ops,cps
 MODIFICATION HISTORY:
	17-Nov-2000  Original by Suzanne Aigrain

(See /home/xmmssc/soft/idl/pro/wfcqc/stat_cl_wfc.pro)