 
      SUBROUTINE DPCHCS(SWITCH,N,H,SLOPE,D,INCFD,IERR)
C***BEGIN PROLOGUE  DPCHCS
C***REFER TO  DPCHIC
C***ROUTINES CALLED  DPCHST,PCHSW
C***REVISION DATE  870707   (YYMMDD)
C***DESCRIPTION
C
C         DPCHCS:  DPCHIC Monotonicity Switch Derivative Setter.
C
C     Called by  DPCHIC  to adjust the values of D in the vicinity of a
C     switch in direction of monotonicity, to produce a more "visually
C     pleasing" curve than that given by  DPCHIM .
C
C ----------------------------------------------------------------------
C
C  Calling sequence:
C
C        PARAMETER  (INCFD = ...)
C        INTEGER  N, IERR
C        DOUBLE PRECISION  SWITCH, H(N), SLOPE(N), D(INCFD,N)
C
C        CALL  DPCHCS (SWITCH, N, H, SLOPE, D, INCFD, IERR)
C
C   Parameters:
C
C     SWITCH -- (input) indicates the amount of control desired over
C           local excursions from data.
C
C     N -- (input) number of data points.  (assumes N.GT.2 .)
C
C     H -- (input) real*8 array of interval lengths.
C     SLOPE -- (input) real*8 array of data slopes.
C           If the data are (X(I),Y(I)), I=1(1)N, then these inputs are:
C                  H(I) =  X(I+1)-X(I),
C              SLOPE(I) = (Y(I+1)-Y(I))/H(I),  I=1(1)N-1.
C
C     D -- (input) real*8 array of derivative values at the data points,
C           as determined by DPCHCI.
C          (output) derivatives in the vicinity of switches in direction
C           of monotonicity may be adjusted to produce a more "visually
C           pleasing" curve.
C           The value corresponding to X(I) is stored in
C                D(1+(I-1)*INCFD),  I=1(1)N.
C           No other entries in D are changed.
C
C     INCFD -- (input) increment between successive values in D.
C           This argument is provided primarily for 2-D applications.
C
C     IERR -- (output) error flag.  should be zero.
C           If negative, trouble in DPCHSW.  (should never happen.)
C
C    -------
C    WARNING:  This routine does no validity-checking of arguments.
C    -------
C
C  Fortran intrinsics used:  DABS, DMAX1, DMIN1.
C
C***END PROLOGUE  DPCHCS
 
 
