SUBROUTINE ZLCOEF(DET,NUP,YDEFUP,TOTUP,
     *                          NLOW,YDEFLW,TOTLOW,COEF,STATUS)
C
C Module Number: 13.8.2
C
C Module Name: ZLCOEF
C
C Keyphrase:
C ----------
C Compute the line mapping function coef. for routine zmplcl
C
C Description:
C ------------
C Using tables of counts versus ydeflection the coefficients for the
C line mapping function are computted by:
C               A = 430/(YPOSLW-yposup)
C               L0 = (2048-yposup)*A
C where: YPOSLW and yposup are the deflections needed to center
C               the diode array on the lower and upper edges
C
C FORTRAN Name: zlcoef.for
C
C
C Keywords of Accessed Files :
C --------------------------
C NONE
C
C Modules Called:
C ---------------
C CDBS:
C       zledge, ZPKSR2
C SDAS:
C       usmput
C
C History:
C --------
C Version       Date      Author        Description
C   1.0       10/mar/86  D. Lindler     Designed and coded
C   2.0       DEC 87     D. LINDLER     NEW SDAS IO/STANDARDS
C------------------------------------------------------------------------
C     INCLUDE FILE FOR THE IRAF77 FORTRAN INTERFACE TO THE IRAF VOS
C
C
C     FILE I/O ACCESS MODES
C
      INTEGER   RDONLY
      PARAMETER (RDONLY = 1)
      INTEGER   RDWRIT
      PARAMETER (RDWRIT = 2)
      INTEGER   WRONLY
      PARAMETER (WRONLY = 3)
      INTEGER   APPEND
      PARAMETER (APPEND = 4)
C
C     CODES FOR DATA TYPES
C
      INTEGER   TYBOOL
      PARAMETER (TYBOOL = 1)
      INTEGER   TYCHAR
      PARAMETER (TYCHAR = 2)
      INTEGER   TYINT
      PARAMETER (TYINT = 4)
      INTEGER   TYREAL
      PARAMETER (TYREAL = 6)
      INTEGER   TYDOUB
      PARAMETER (TYDOUB = 7)
C
C     UMSPUT DESTINATIONS -- CB, DAO, 4-SEP-87
C
      INTEGER STDOUT
      PARAMETER (STDOUT = 1)
      INTEGER STDERR
      PARAMETER (STDERR = 2)
C
C     UHDAS HEADER PARM TYPES -- CB, DAO, 5-SEP-87
C
      INTEGER GENHDR
      PARAMETER (GENHDR = 0)
      INTEGER IMSPEC
      PARAMETER (IMSPEC = 1)
C
C     THIS SECTION IS FOR PARAMETERS RELEVANT TO TABLE I/O.
C
C     THESE MAY BE SET BY UTPPTI AND/OR READ BY UTPGTI:
C
C                                       LENGTH OF ROW (UNIT = SIZE OF REAL)
      INTEGER   TBRLEN
      PARAMETER (TBRLEN = 1)
C                                       INCREASE ROW LENGTH
      INTEGER   TBIRLN
      PARAMETER (TBIRLN = 2)
C                                       NUMBER OF ROWS TO ALLOCATE
      INTEGER   TBALLR
      PARAMETER (TBALLR = 3)
C                                       INCREASE ALLOC NUM OF ROWS
      INTEGER   TBIALR
      PARAMETER (TBIALR = 4)
C                                       WHICH TYPE OF TABLE? (ROW OR COLUMN)
      INTEGER   TBWTYP
      PARAMETER (TBWTYP = 5)
C                                       MAXIMUM NUMBER OF USER PARAMETERS
      INTEGER   TBMXPR
      PARAMETER (TBMXPR = 6)
C                                       MAXIMUM NUMBER OF COLUMNS
      INTEGER   TBMXCL
      PARAMETER (TBMXCL = 7)
C                                       TYPE = ROW-ORDERED TABLE
      INTEGER   TBTYPR
      PARAMETER (TBTYPR = 11)
C                                       TYPE = COLUMN-ORDERED TABLE
      INTEGER   TBTYPC
      PARAMETER (TBTYPC = 12)
C
C     THESE MAY BE READ BY UTPGTI BUT MAY NOT BE SET:
C
C                                       NUMBER OF ROWS WRITTEN TO
      INTEGER   TBNROW
      PARAMETER (TBNROW = 21)
C
C     END IRAF77.INC
C
C INPUT:
C
        INTEGER         DET
C                                    ---> HRS DETECTOR NUMBER (1 OR 2)
        INTEGER         NUP
C                                    ---> NUMBER OF POINTS (UPPER EDGE)
        DOUBLE PRECISION YDEFUP(1)
C                                    ---> TABLE OF YDEF. UPPER EDGE
        DOUBLE PRECISION TOTUP(1)
C                                    ---> TABLE OF COUNTS, UPPER EDGE
        INTEGER         NLOW
C                                    ---> NUMBER OF POINTS (LOWER EDGE)
        DOUBLE PRECISION YDEFLW(1)
C                                    ---> Y-DEFLECTIONS (LOWER EDGE)
        DOUBLE PRECISION TOTLOW(1)
C                                    ---> COUNTS (LOWER EDGE)
C
C OUTPUT:
C
        DOUBLE PRECISION COEF(5)
C                                    ---> COEFFICIENT ARRAY
        INTEGER         STATUS
C                                    ---> STATUS
C
C LOCAL VARIABLES
C
        CHARACTER*130   MESS
C                                    ---> MESS FOR TERMINAL
        CHARACTER*130   CONTXT
C                                    ---> WHAT HAPPENED
        DOUBLE PRECISION YPOSUP,YPOSLW
C                                    ---> EDGE LOCATIONS
        DOUBLE PRECISION L0,A
C                                    ---> MAPPING COEFFICIENTS
        INTEGER ISTAT
C----------------------------------------------------------------------
C
C DO WE HAVE ENOUGH DATA ON EACH EDGE?
C
        IF((NUP.LT.4).OR.(NLOW.LT.4)) THEN
             CONTXT='INSUFFICIENT OBSERVATIONS OF UPPER OR LOWER EDGE'
             GO TO 999
        ENDIF
C
C SORT TABLES IN ORDER OF ASCENDING Y-DEFLECTION
C
        CALL ZPKSR2(NUP,YDEFUP,TOTUP)
        CALL ZPKSR2(NLOW,YDEFLW,TOTLOW)
C
C LOCATED EDGE POSITIONS
C
        CALL ZLEDGE(NUP,YDEFUP,TOTUP,YPOSUP,STATUS)
        IF (STATUS.NE.0) THEN
                CONTXT='UPPER EDGE NOT FOUND'
                GO TO 999
        ENDIF
        WRITE(MESS,99)YPOSUP
99      FORMAT(1X,'UPPER EDGE LOCATION =',F8.2)
        CALL UMSPUT(MESS,STDOUT,0,ISTAT)
        CALL ZLEDGE(NLOW,YDEFLW,TOTLOW,YPOSLW,STATUS)
        IF (STATUS.NE.0) THEN
                CONTXT='LOWER EDGE NOT FOUND'
                GO TO 999
        ENDIF
        WRITE(MESS,199)YPOSLW
199     FORMAT(1X,'LOWER EDGE LOCATION =',F8.2)
        CALL UMSPUT(MESS,STDOUT,0,ISTAT)
C
C COMPUTE COEFFICIENTS
C
        A=430.0/(YPOSLW-YPOSUP)
        L0=(2048-YPOSUP)*A
        WRITE(MESS,299)DET,L0,A
299     FORMAT(1X,'COEF. FOR DETECTOR',I2,'    L0=',F8.2,'   A=',F8.5)
        CALL UMSPUT(MESS,STDOUT,0,ISTAT)
C                                         FOR CONSISTENCY WITH SAMPLE COEF.
        COEF(1)=L0
        COEF(2)=0.0
C                                    ---> NOT IMPLEMENTED (ERROR IN L0)
        COEF(3)=A
        COEF(4)=0.0
C                                    ---> NOT IMPLEMENTED (ERROR IN A)
        STATUS=0
        GO TO 1000
C
C ERROR ENCOUNTERED
C
999     STATUS=1
C
C LET'S GET OUT OF HERE
C
1000    CALL UMSPUT(CONTXT,STDOUT+STDERR,0,ISTAT)
        RETURN
        END