*DECK DFDTRU SUBROUTINE DFDTRU (X, F, D) C***BEGIN PROLOGUE DFDTRU C***SUBSIDIARY C***PURPOSE Compute exact function values for DEVCHK. C***LIBRARY SLATEC (PCHIP) C***TYPE DOUBLE PRECISION (FDTRUE-S, DFDTRU-D) C***KEYWORDS PCHIP EVALUATOR QUICK CHECK C***AUTHOR Fritsch, F. N., (LLNL) C***DESCRIPTION C C COMPUTE EXACT FUNCTION VALUES IN DOUBLE PRECISION. C C F(X) = X*(X+1)*(X-2) C C***ROUTINES CALLED (NONE) C***REVISION HISTORY (YYMMDD) C 820601 DATE WRITTEN C 890618 REVISION DATE from Version 3.2 C 890706 Cosmetic changes to prologue. (WRB) C 891214 Prologue converted to Version 4.0 format. (BAB) C 900315 Revised prologue. (FNF) C 900316 Deleted variables ONE and TWO. (FNF) C 900321 Changed name of d.p. version from DFTRUE to DFDTRU. C***END PROLOGUE DFDTRU DOUBLE PRECISION X, F, D DOUBLE PRECISION FACT1, FACT2, XX C C***FIRST EXECUTABLE STATEMENT DFDTRU XX = X FACT1 = XX + 1 FACT2 = XX - 2 F = XX * FACT1 * FACT2 D = FACT1*FACT2 + XX*(FACT1 + FACT2) C RETURN C------------- LAST LINE OF DFDTRU FOLLOWS ----------------------------- END