CTITLESAHCSC _ PERFORM OPTIONAL FIRST-TRACE SCALING FOR PROCESS AVEL.
C***********************************************************************
C                 COPYRIGHT ATLANTIC RICHFIELD COMPANY 1991            *
C***********************************************************************
C@PROCESS VECTOR(LEVEL(2) REPORT(XLIST))
C
CA    AUTHOR             H. W. SWAN
CA    DESIGNER           H. W. SWAN
CA    SYSTEM             IBM/CRAY
CA    LANGUAGE           VS FORTRAN VERSION 2.2
CA    WRITTEN            12-03-87
CA    LAST REVISED       07-13-88
C
C     REVISED            07-13-88  HWS  INITIALIZED SUM TO 0.
C     REVISED            05-23-91  JJC  CHANGED IMPLICIT NONE TO (A-Z).
C     REVISED            12-17-91  JJC  MODIFIED TO MEET SPARC STANDARDS
C
CA
CA    CALLING SEQUENCE:
CA      CALL HCSCL(TRIN, NSIN, IFLV, SCALE, IFRST)
CA
CA   IN/OUT   ARGUMENT   TYPE   DESCRIPTION
CA   ______   ________   ____   ___________
CA
CA    IN       TRIN     (R4)   THE INPUT TRACE
CA    IN       NSIN      I4    THE NUMBER OF SAMPLES IN THE INPUT TRACE
CA    IN       IFLV      I4    THE INDEX OF THE FIRST LIVE VALUE
CA   IN/OUT    SCALE     R4    THE SCALE FACTOR TO APPLY TO THE TRACE
CA   IN/OUT    IFRST     I4    A FLAG DENOTING WHETHER THIS IS THE
CA                             FIRST TRACE
CA
CA
CA
CA   PURPOSE:
CA
CA      IF IFRST .EQ. 0, THIS SUBROUTINE SCALES THE TRACE TO HAVE
CA      A UNITY R.M.S. VALUE.  IT THEN SETS IFRST = 1 FOR THE NEXT PASS,
CA      AND RETURNS THE SCALE FACTOR IT USED IN SCALE.  OTHERWISE,
CA      IT SCALES THE TRACE, BASED UPON THE SAME SCALE FACTOR PASSED
CA      IN SCALE.
CA
CA
CA   SUBROUTINES CALLED:   NONE
CA
CA
        SUBROUTINE SAHCSC(TRIN, NSIN, IFLV, SCALE, IFRST)
C
CJJ     IMPLICIT         NONE
        IMPLICIT INTEGER (A-Z)
C
        INTEGER          NSIN, IFLV, IFRST, I
        REAL             TRIN, SCALE
        DIMENSION        TRIN(NSIN)
        DOUBLE PRECISION SUM

        IF(IFRST .EQ. 0) THEN
            IF(IFLV .GE. NSIN) RETURN
            SUM = 0.0
            DO 100 I=IFLV, NSIN
                SUM = SUM + TRIN(I)**2
 100            CONTINUE
            SCALE = 1.0 / DSQRT(SUM)
C           WRITE (*,*) ' SCALE = ', SCALE
            IFRST = 1
            ENDIF

        DO 200 I=IFLV, NSIN
 200        TRIN(I) = TRIN(I) * SCALE
        RETURN
        END