*DECK DQK41 SUBROUTINE DQK41 (F, A, B, RESULT, ABSERR, RESABS, RESASC) C***BEGIN PROLOGUE DQK41 C***PURPOSE To compute I = Integral of F over (A,B), with error C estimate C J = Integral of ABS(F) over (A,B) C***LIBRARY SLATEC (QUADPACK) C***CATEGORY H2A1A2 C***TYPE DOUBLE PRECISION (QK41-S, DQK41-D) C***KEYWORDS 41-POINT GAUSS-KRONROD RULES, QUADPACK, QUADRATURE C***AUTHOR Piessens, Robert C Applied Mathematics and Programming Division C K. U. Leuven C de Doncker, Elise C Applied Mathematics and Programming Division C K. U. Leuven C***DESCRIPTION C C Integration rules C Standard fortran subroutine C Double precision version C C PARAMETERS C ON ENTRY C F - Double precision C Function subprogram defining the integrand C FUNCTION F(X). The actual name for F needs to be C declared E X T E R N A L in the calling program. C C A - Double precision C Lower limit of integration C C B - Double precision C Upper limit of integration C C ON RETURN C RESULT - Double precision C Approximation to the integral I C RESULT is computed by applying the 41-POINT C GAUSS-KRONROD RULE (RESK) obtained by optimal C addition of abscissae to the 20-POINT GAUSS C RULE (RESG). C C ABSERR - Double precision C Estimate of the modulus of the absolute error, C which should not exceed ABS(I-RESULT) C C RESABS - Double precision C Approximation to the integral J C C RESASC - Double precision C Approximation to the integral of ABS(F-I/(B-A)) C over (A,B) C C***REFERENCES (NONE) C***ROUTINES CALLED D1MACH C***REVISION HISTORY (YYMMDD) C 800101 DATE WRITTEN C 890531 Changed all specific intrinsics to generic. (WRB) C 890531 REVISION DATE from Version 3.2 C 891214 Prologue converted to Version 4.0 format. (BAB) C***END PROLOGUE DQK41