1 2 SUBROUTINE DQK15W(F,W,P1,P2,P3,P4,KP,A,B,RESULT,ABSERR,RESABS, 3 1 RESASC) 4C***BEGIN PROLOGUE DQK15W 5C***DATE WRITTEN 810101 (YYMMDD) 6C***REVISION DATE 830518 (YYMMDD) 7C***CATEGORY NO. H2A2A2 8C***KEYWORDS 15-POINT GAUSS-KRONROD RULES 9C***AUTHOR PIESSENS, ROBERT, APPLIED MATH. AND PROGR. DIV. - 10C K. U. LEUVEN 11C DE DONCKER, ELISE, APPLIED MATH. AND PROGR. DIV. - 12C K. U. LEUVEN 13C***PURPOSE To compute I = Integral of F*W over (A,B), with error 14C estimate 15C J = Integral of ABS(F*W) over (A,B) 16C***DESCRIPTION 17C 18C Integration rules 19C Standard fortran subroutine 20C Double precision version 21C 22C PARAMETERS 23C ON ENTRY 24C F - Double precision 25C Function subprogram defining the integrand 26C function F(X). The actual name for F needs to be 27C declared E X T E R N A L in the driver program. 28C 29C W - Double precision 30C Function subprogram defining the integrand 31C WEIGHT function W(X). The actual name for W 32C needs to be declared E X T E R N A L in the 33C calling program. 34C 35C P1, P2, P3, P4 - Double precision 36C Parameters in the WEIGHT function 37C 38C KP - Integer 39C Key for indicating the type of WEIGHT function 40C 41C A - Double precision 42C Lower limit of integration 43C 44C B - Double precision 45C Upper limit of integration 46C 47C ON RETURN 48C RESULT - Double precision 49C Approximation to the integral I 50C RESULT is computed by applying the 15-point 51C Kronrod rule (RESK) obtained by optimal addition 52C of abscissae to the 7-point Gauss rule (RESG). 53C 54C ABSERR - Double precision 55C Estimate of the modulus of the absolute error, 56C which should equal or exceed ABS(I-RESULT) 57C 58C RESABS - Double precision 59C Approximation to the integral of ABS(F) 60C 61C RESASC - Double precision 62C Approximation to the integral of ABS(F-I/(B-A)) 63C***REFERENCES (NONE) 64C***ROUTINES CALLED D1MACH 65C***END PROLOGUE DQK15W 66 67 68