SLATEC Routines --- SINTRP ---

*DECK SINTRP
      SUBROUTINE SINTRP (X, Y, XOUT, YOUT, YPOUT, NEQN, KOLD, PHI, IVC,
     +   IV, KGI, GI, ALPHA, OG, OW, OX, OY)
C***BEGIN PROLOGUE  SINTRP
C***PURPOSE  Approximate the solution at XOUT by evaluating the
C            polynomial computed in STEPS at XOUT.  Must be used in
C            conjunction with STEPS.
C***LIBRARY   SLATEC (DEPAC)
C***CATEGORY  I1A1B
C***TYPE      SINGLE PRECISION (SINTRP-S, DINTP-D)
C***KEYWORDS  ADAMS METHOD, DEPAC, INITIAL VALUE PROBLEMS, ODE,
C             ORDINARY DIFFERENTIAL EQUATIONS, PREDICTOR-CORRECTOR,
C             SMOOTH INTERPOLANT
C***AUTHOR  Watts, H. A., (SNLA)
C***DESCRIPTION
C
C   The methods in subroutine  STEPS  approximate the solution near  X
C   by a polynomial.  Subroutine  SINTRP  approximates the solution at
C   XOUT  by evaluating the polynomial there.  Information defining this
C   polynomial is passed from  STEPS  so  SINTRP  cannot be used alone.
C
C   Subroutine STEPS is completely explained and documented in the text,
C   "Computer Solution of Ordinary Differential Equations, the Initial
C   Value Problem"  by L. F. Shampine and M. K. Gordon.
C
C   Input to SINTRP --
C
C   The user provides storage in the calling program for the arrays in
C   the call list
C      DIMENSION Y(NEQN),YOUT(NEQN),YPOUT(NEQN),PHI(NEQN,16),OY(NEQN)
C                AND ALPHA(12),OG(13),OW(12),GI(11),IV(10)
C   and defines
C      XOUT -- point at which solution is desired.
C   The remaining parameters are defined in  STEPS  and passed to
C   SINTRP  from that subroutine
C
C   Output from  SINTRP --
C
C      YOUT(*) -- solution at  XOUT
C      YPOUT(*) -- derivative of solution at  XOUT
C   The remaining parameters are returned unaltered from their input
C   values.  Integration with  STEPS  may be continued.
C
C***REFERENCES  H. A. Watts, A smoother interpolant for DE/STEP, INTRP
C                 II, Report SAND84-0293, Sandia Laboratories, 1984.
C***ROUTINES CALLED  (NONE)
C***REVISION HISTORY  (YYMMDD)
C   840201  DATE WRITTEN
C   890831  Modified array declarations.  (WRB)
C   890831  REVISION DATE from Version 3.2
C   891214  Prologue converted to Version 4.0 format.  (BAB)
C   920501  Reformatted the REFERENCES section.  (WRB)
C***END PROLOGUE  SINTRP