SLATEC Routines --- DQK61 ---


*DECK DQK61
      SUBROUTINE DQK61 (F, A, B, RESULT, ABSERR, RESABS, RESASC)
C***BEGIN PROLOGUE  DQK61
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 (QK61-S, DQK61-D)
C***KEYWORDS  61-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 rule
C        Standard fortran subroutine
C        Double precision version
C
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 61-point
C                    Kronrod rule (RESK) obtained by optimal addition of
C                    abscissae to the 30-point Gauss rule (RESG).
C
C           ABSERR - Double precision
C                    Estimate of the modulus of the absolute error,
C                    which should equal or 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
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  DQK61