C
C
C-----------------------------------------------------------------------------
C
C	SUBROUTINE:	G E M I N D
C
C	AUTHOR:		Han Lasance
C
C	DATE:		15-FEB-82
C
C	VERSION:	1.0
C
C	MODIFIED BY:	
C
C	PURPOSE:	To fill array GEM with interpolated indices in the 
C			order of descending corresponding values in array 
C			IKL.
C
C	DESCRIPTION:	
C			Example:
C			In the figure below GEM(1) will be a value 
C			between 5 and 6, GEM(2) a value between 1 and 2
C
C	 	                      l
C       IKL(I)	        l             l
C		        l             l      l
C		 l      l             l      l		     l
C		 l      l      l      l      l  . . . . .    l      l
C		 -----------------------------  . . . . .  ------------
C	Index I: 1      2      3      4      5             NKL-1   NKL
C		 ^      ^                     		     ^      ^	
C	Values: 0-99 100-199 ..   ..   ..   ..  . . . . .    .. 3900-4095
C	(NKL=40)
C
C		SEARCH PROCEDURE:
C
C		- Find maximum (MAX) and biggest neighbour (BNE) in array IKL
C		  starting from the top(J=1), from the beginning (J=3) and
C		  between those two maxima(J=2).
C		- If BNE > MAX/2  then  FAC:= BNE/MAX (0 < FAC <= 1.)
C			          else  FAC:= 0.
C		- GEM(J) := (Index(MAX)+FAC*Index(BNE))/(FAC+1) so that if:
C				FAC = 0: GEM(J) = Index(MAX)
C				FAC = 1: GEM(J) = (Index(MAX)+Index(BNE))/2
C			
C
C	INPUT  FILES:	None
C
C	OUTPUT FILES:	None
C
C	LUNS:		None
C
C	BATCH:		Not used
C
C	EVENT FLAGS:	None
C
C	CALL:		GEMIND	(IKL, NKL, GEM, NGEM)
C
C	ARGUMENTS:	NAME		DESCRIPTOIN
C	    I		IKL	Histogram array containing the number of 
C				occurrences of a certain value range.
C	    I		NKL	Number of elements in array IKL.
C	    O		GEM	Array which will be filled with real numbers,
C				indicating an interpolated index pointing to a
C				max. in the histogram. The order in which they
C				are stored is from high to low.
C	    I		NGEM	The number of maxima wanted in array GEM.
C	    O		NGEM: The number of maxima wanted in array GEM.
C
C	CALLS TO:	None
C
C	PARAMETERS:	NAME		DESCRIPTION
C
C	BUILDING:	None
C
C-----------------------------------------------------------------------------
C
C

C
C
	SUBROUTINE	GEMIND	(IKL, NKL, GEM, NGEM)
C
C
	INTEGER		IKL(1)
	REAL		GEM(1)


	DO 30 J=1,NGEM
	MAX=IKL(1)

	DO 10 I=2,NKL
	IF(IKL(I).LE.MAX) GO TO 10
	MAX=IKL(I)
	ISAV=I
10	CONTINUE

	IS1=ISAV-1
	IF(ISAV.EQ.NKL) GO TO 20
	IF(IKL(ISAV+1).GT.IKL(ISAV-1)) IS1=ISAV+1
20	FAC=0.
	IF(IKL(IS1).GT.IKL(ISAV)/2) FAC=FLOAT(IKL(IS1))/FLOAT(IKL(ISAV))
	GEM(J)=(FLOAT(ISAV)+FAC*FLOAT(IS1))/(1.+FAC)
	IKL(ISAV)=-1			! Don't look at this one any more
	IF(ISAV.NE.1) IKL(ISAV-1)=-1	! Don't look at this one any more
	IF(ISAV.NE.NKL) IKL(ISAV+1)=-1	! Don't look at this one any more
30	CONTINUE


	DO 50 I=1,NGEM
	ISAV=0
	RMAX=GEM(I)

	DO 40 J=I+1,NGEM
	IF(GEM(J).LE.RMAX) GO TO 40
	RMAX=GEM(J)
	ISAV=J
40	CONTINUE

	IF(ISAV.EQ.0) GO TO 50
	TEMP=GEM(I)
	GEM(I)=GEM(ISAV)
	GEM(ISAV)=TEMP
50	CONTINUE


	RETURN
	END