DQC25C(3)

SYNOPSIS
SUBROUTINE DQC25C (F, A, B, C, RESULT, ABSERR, KRUL, NEVAL)

NAME
dqc25c - To compute I = Integral of F*W over (A,B) with error estimate, where W(X) = 1/(X-C)

LIBRARY
SLATEC (QUADPACK)

CATEGORY
H2A2A2, J4

TYPE
DOUBLE PRECISION (QC25C-S, DQC25C-D)

KEYWORDS
25-POINT CLENSHAW-CURTIS INTEGRATION, QUADPACK, QUADRATURE

AUTHOR
Piessens, Robert Applied Mathematics and Programming Division K. U. Leuven de Doncker, Elise Applied Mathematics and Programming Division K. U. Leuven

DESCRIPTION
Integration rules for the computation of CAUCHY PRINCIPAL VALUE integrals Standard fortran subroutine Double precision version PARAMETERS F - Double precision Function subprogram defining the integrand function F(X). The actual name for F needs to be declared E X T E R N A L in the driver program. A - Double precision Left end point of the integration interval B - Double precision Right end point of the integration interval, B.GT.A C - Double precision Parameter in the WEIGHT function RESULT - Double precision Approximation to the integral result is computed by using a generalized Clenshaw-Curtis method if C lies within ten percent of the integration interval. In the other case the 15-point Kronrod rule obtained by optimal addition of abscissae to the 7-point Gauss rule, is applied. ABSERR - Double precision Estimate of the modulus of the absolute error, which should equal or exceed ABS(I-RESULT) KRUL - Integer Key which is decreased by 1 if the 15-point Gauss-Kronrod scheme has been used NEVAL - Integer Number of integrand evaluations

REFERENCES
(NONE)

ROUTINES CALLED
DQCHEB, DQK15W, DQWGTC

REVISION HISTORY (YYMMDD)
810101 DATE WRITTEN
890531 Changed all specific intrinsics to generic. (WRB)
890531 REVISION DATE from Version 3.2
891214 Prologue converted to Version 4.0 format. (BAB)