qk15w.f
SUBROUTINE QK15W (F, W, P1, P2, P3, P4, KP, A, B, RESULT, ABSERR,
+ RESABS, RESASC)
C***BEGIN PROLOGUE QK15W
C***PURPOSE To compute I = Integral of F*W over (A,B), with error
C estimate
C J = Integral of ABS(F*W) over (A,B)
C***LIBRARY SLATEC (QUADPACK)
C***CATEGORY H2A2A2
C***TYPE SINGLE PRECISION (QK15W-S, DQK15W-D)
C***KEYWORDS 15-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 Real version
C
C PARAMETERS
C ON ENTRY
C F - Real
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 driver program.
C
C W - Real
C Function subprogram defining the integrand
C WEIGHT function W(X). The actual name for W
C needs to be declared E X T E R N A L in the
C calling program.
C
C P1, P2, P3, P4 - Real
C Parameters in the WEIGHT function
C
C KP - Integer
C Key for indicating the type of WEIGHT function
C
C A - Real
C Lower limit of integration
C
C B - Real
C Upper limit of integration
C
C ON RETURN
C RESULT - Real
C Approximation to the integral I
C RESULT is computed by applying the 15-point
C Kronrod rule (RESK) obtained by optimal addition
C of abscissae to the 7-point Gauss rule (RESG).
C
C ABSERR - Real
C Estimate of the modulus of the absolute error,
C which should equal or exceed ABS(I-RESULT)
C
C RESABS - Real
C Approximation to the integral of ABS(F)
C
C RESASC - Real
C Approximation to the integral of ABS(F-I/(B-A))
C
C***REFERENCES (NONE)
C***ROUTINES CALLED R1MACH
C***REVISION HISTORY (YYMMDD)
C 810101 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 QK15W