USER'S INSTRUCTIONS FOR PROGRAM EVAL
      ------ ------------ --- ------- ----

      ROBERT H. BLESSING
      HAUPTMAN-WOODWARD INSTITUTE
      73 HIGH STREET
      BUFFALO, NEW YORK 14203, USA
      TELEPHONE:  (716) 856-9600
      ELECTRONIC MAIL:  Blessing@HWI.Buffalo.Edu

      INPUT FOR PROGRAM EVAL CONSISTS OF:

      1.  "eval.dat", WHICH IS AN ASCII FILE OF CONTROL DATA AND 
          PARAMETERS WRITTEN BY PROGRAM PROGRAM LEVY.
      2.  THE SAME REFLECTION DATA FILE USED AS INPUT TO PROGRAM LEVY.

      THE FORTRAN CODE FOR READING THIS INPUT IS QUOTED BELOW.

      OUTPUT FROM PROGRAM EVAL CONSISTS OF TWO FORMATTED, ASCII FILES
      OF REFLECTION DATA:  'EDATA.HKL', WHICH IS HKL-SORTED, AND
      'EDATA.EEE', WHICH IS E-SORTED.  THESE FILES ARE WRITTEN BY
      SUBROUTINE WRITE1, ALSO QUOTED BELOW.

------------------------------------------------------------------------

      CONTROL DATA FILE "eval.dat"
                        ==========

      NOTE THAT THERE IS PROVISION FOR AN OPTIONAL RECORD TO BE ADDED BY
      THE USER AT THE END OF THE 'EVAL.DAT' INPUT FILE PREPARED BY
      PROGRAM LEVY OR PROGRAM ROGERS TO SUPPLY VALUES FOR:

      NLIST, CUTOFF, EMIN, EMAX (I10,3F10.0)

      NLIST  - MAXIMUM NUMBER OF REFLECTIONS TO BE PRINTED IN THE LISTS
               OF THE LARGEST AND SMALLEST SIGNIFICANT E-MAGNITUDES.
      CUTOFF - MINIMUM E/SIGMA(E) FOR THE PRINTED LISTS OF SIGNIFICANT
               E-MAGNITUDES.  DEFAULT:  CUTOFF = 3.
      EMIN   - MINIMUM E-MAGNITUDE FOR REFLECTIONS PRINTED IN THE LIST
               OF LARGEST E-MAGNITUDES.  DEFAULT:  EMIN = 1.5.
      EMAX   - MAXIMUM E-MAGNITUDE FOR REFLECTIONS PRINTED IN THE LIST
               OF SMALLEST E-MAGNITUDES.  DEFAULT:  EMAX = 0.5.

------------------------------------------------------------------------
      .
      .
      .
C
C READ CONTROL DATA AND PARAMETERS FROM PROGRAM LEVY.
C
      OPEN (UNIT=IO1,FILE='eval.dat',STATUS='OLD')
      READ (IO1,999) BTIME
      READ (IO1,999) BDATE
      READ (IO1,997) ITYPE
      READ (IO1,999) TITLE
      READ (IO1,999) FILE
      READ (IO1,999) LATT
      READ (IO1,999) PTGP
      READ (IO1,998) CELL
      READ (IO1,999) XRAY
      READ (IO1,997) NEL
      DO 5 I=1,NEL
        READ (IO1,996) EL(I),XI(I),ZI(I),A1(I),B1(I),A2(I),B2(I)
        READ (IO1,995) A3(I),B3(I),A4(I),B4(I),C0(I),FP(I),FPP(I)
 5    CONTINUE
      READ (IO1,998) SMIN,SMAX
      READ (IO1,994) SCALEK
      READ (IO1,994)       B(1,1),B(1,2),B(1,3),B(2,2),B(2,3),B(3,3)
      READ (IO1,994,END=9) C(1,1),C(1,2),C(1,3),C(2,2),C(2,3),C(3,3)
      READ (IO1,993,END=9) ((COV(I,J),J=1,13),I=1,13)
      READ (IO1,992,END=9) NLIST,CUTOFF,EMAX,EMIN
 999  FORMAT (1X,A)
 998  FORMAT (1X,6F10.0)
 997  FORMAT (1X,I6)
 996  FORMAT (1X,A2,F10.2,F6.0,4(1X,F10.6))
 995  FORMAT (1X,5(1X,F10.6),2X,2(1X,F10.6))
 994  FORMAT (1X,6E12.5)
 993  FORMAT (1X,7E10.3)
 992  FORMAT (I10,3F10.0)
 9    CLOSE (UNIT=IO1,STATUS='KEEP')
      .
      .
      .
      IF (ITYPE.LT.3) THEN
        FORM='UNFORMATTED'
      ELSE
        FORM='FORMATTED'
      END IF
      OPEN (UNIT=IO1,FILE=FILE,STATUS='OLD',FORM=FORM)
      .
      .
      .
      CALL READ1 (ITYPE,IUNIT,IEND,IH,IK,IL,FSQ,SIGFSQ,F,SIGF)
C-----------------------------------------------------------------------
      SUBROUTINE READ1 (ITYPE,IUNIT,IEND,IH,IK,IL,FSQ,SIGFSQ,F,SIGF)
      FSQ=0
      SIGFSQ=0
      F=0
      SIGF=0
 1    IF (ITYPE.EQ.0) READ (IUNIT,  END=9) IH,IK,IL,FSQ,SIGFSQ,F,SIGF
      IF (ITYPE.EQ.1) READ (IUNIT,  END=9) IH,IK,IL,FSQ,SIGFSQ
      IF (ITYPE.EQ.2) READ (IUNIT,  END=9) IH,IK,IL,F,  SIGF
      IF (ITYPE.EQ.3) READ (IUNIT,*,END=9) IH,IK,IL,FSQ,SIGFSQ,F,SIGF
      IF (ITYPE.EQ.4) READ (IUNIT,*,END=9) IH,IK,IL,FSQ,SIGFSQ
      IF (ITYPE.EQ.5) READ (IUNIT,*,END=9) IH,IK,IL,F,  SIGF
      IF (SIGFSQ.LE.0.AND.SIGF.LE.0) GO TO 1
      IF (FSQ.LE.0.AND.F.LE.0) GO TO 1
      IF ((ITYPE.EQ.1.OR.ITYPE.EQ.4).AND.SIGFSQ.GT.0)
     & CALL FSQTOF (FSQ,SIGFSQ,F,SIGF)
      IF ((ITYPE.EQ.2.OR.ITYPE.EQ.5).AND.SIGF.GT.0)
     & CALL FTOFSQ (F,SIGF,FSQ,SIGFSQ)
      IF (F*SIGF.LE.0) GO TO 1
      RETURN
 9    IEND=1
      RETURN
      END
C-----------------------------------------------------------------------
      SUBROUTINE FSQTOF (FSQ,SIGFSQ,F,SIGF)
      IF (FSQ.LT.0) THEN
        F=0
      ELSE
        F=SQRT(FSQ)
      END IF
      IF (FSQ.LE.SIGFSQ) THEN
        SIGF=0.5*SQRT(SIGFSQ)
      ELSE
        SIGF=0.5*SIGFSQ/F
      END IF
      RETURN
      END
C-----------------------------------------------------------------------
      SUBROUTINE FTOFSQ (F,SIGF,FSQ,SIGFSQ)
      IF (F.LT.0) F=0
      IF (SIGF.LT.0) SIGF=0
      FSQ=F**2
      SIGFSQ=MAX(2*F*SIGF,4*SIGF**2)
      RETURN
      END
C-----------------------------------------------------------------------
      SUBROUTINE WRITE1 (IFILE,J,K,L,FSQ,SIGFSQ,F,SIGF,E,SIGE)
      WRITE (IFILE,'(1X,3I5,4(E12.4,E10.2))')
     & IH,IK,IL,FSQ,SIGFSQ,F,SIGF,E,SIGE
      RETURN
      END
C-----------------------------------------------------------------------