DINTYD(3)

SYNOPSIS
SUBROUTINE DINTYD (T, K, YH, NYH, DKY, IFLAG)

NAME
dintyd - Subsidiary to DDEBDF

LIBRARY
SLATEC

TYPE
DOUBLE PRECISION (INTYD-S, DINTYD-D)

AUTHOR
Watts, H. A., (SNLA)

DESCRIPTION
DINTYD approximates the solution and derivatives at T by polynomial interpolation. Must be used in conjunction with the integrator package DDEBDF. ---------------------------------------------------------------------- DINTYD computes interpolated values of the K-th derivative of the dependent variable vector Y, and stores it in DKY. This routine is called by DDEBDF with K = 0,1 and T = TOUT, but may also be called by the user for any K up to the current order. (see detailed instructions in LSODE usage documentation.) ---------------------------------------------------------------------- The computed values in DKY are gotten by interpolation using the Nordsieck history array YH. This array corresponds uniquely to a vector-valued polynomial of degree NQCUR or less, and DKY is set to the K-th derivative of this polynomial at T. The formula for DKY is.. Q DKY(I) = Sum C(J,K) * (T - TN)**(J-K) * H**(-J) * YH(I,J+1) J=K where C(J,K) = J*(J-1)*...*(J-K+1), Q = NQCUR, TN = TCUR, H = HCUR. The quantities NQ = NQCUR, L = NQ+1, N = NEQ, TN, and H are communicated by common. The above sum is done in reverse order. IFLAG is returned negative if either K or T is out of bounds. ----------------------------------------------------------------------

SEE ALSO
DDEBDF

ROUTINES CALLED
(NONE)

COMMON BLOCKS
DDEBD1

REVISION HISTORY (YYMMDD)
820301 DATE WRITTEN
890911 Removed unnecessary intrinsics. (WRB)
891214 Prologue converted to Version 4.0 format. (BAB)
900328 Added TYPE section. (WRB)
910722 Updated AUTHOR section. (ALS)