qk15i.f
SUBROUTINE QK15I (F, BOUN, INF, A, B, RESULT, ABSERR, RESABS,
+ RESASC)
C***BEGIN PROLOGUE QK15I
C***PURPOSE The original (infinite integration range is mapped
C onto the interval (0,1) and (A,B) is a part of (0,1).
C it is the purpose to compute
C I = Integral of transformed integrand over (A,B),
C J = Integral of ABS(Transformed Integrand) over (A,B).
C***LIBRARY SLATEC (QUADPACK)
C***CATEGORY H2A3A2, H2A4A2
C***TYPE SINGLE PRECISION (QK15I-S, DQK15I-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 Rule
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 calling program.
C
C BOUN - Real
C Finite bound of original integration
C Range (SET TO ZERO IF INF = +2)
C
C INF - Integer
C If INF = -1, the original interval is
C (-INFINITY,BOUND),
C If INF = +1, the original interval is
C (BOUND,+INFINITY),
C If INF = +2, the original interval is
C (-INFINITY,+INFINITY) AND
C The integral is computed as the sum of two
C integrals, one over (-INFINITY,0) and one over
C (0,+INFINITY).
C
C A - Real
C Lower limit for integration over subrange
C of (0,1)
C
C B - Real
C Upper limit for integration over subrange
C of (0,1)
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 J
C
C RESASC - Real
C Approximation to the integral of
C ABS((TRANSFORMED INTEGRAND)-I/(B-A)) over (A,B)
C
C***REFERENCES (NONE)
C***ROUTINES CALLED R1MACH
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 QK15I