! D01AQF Example Program Text ! Mark 24 Release. NAG Copyright 2012. Module d01aqfe_mod ! D01AQF Example Program Module: ! Parameters and User-defined Routines ! .. Use Statements .. Use nag_library, Only: nag_wp ! .. Implicit None Statement .. Implicit None ! .. Parameters .. Integer, Parameter :: lw = 800, nout = 6 Integer, Parameter :: liw = lw/4 Contains Function g(x) ! .. Function Return Value .. Real (Kind=nag_wp) :: g ! .. Scalar Arguments .. Real (Kind=nag_wp), Intent (In) :: x ! .. Local Scalars .. Real (Kind=nag_wp) :: aa ! .. Executable Statements .. aa = 0.01E0_nag_wp g = 1.0E0_nag_wp/(x**2+aa**2) Return End Function g End Module d01aqfe_mod Program d01aqfe ! D01AQF Example Main Program ! .. Use Statements .. Use nag_library, Only: d01aqf, nag_wp Use d01aqfe_mod, Only: g, liw, lw, nout ! .. Implicit None Statement .. Implicit None ! .. Local Scalars .. Real (Kind=nag_wp) :: a, abserr, b, c, epsabs, epsrel, & result Integer :: ifail ! .. Local Arrays .. Real (Kind=nag_wp), Allocatable :: w(:) Integer, Allocatable :: iw(:) ! .. Executable Statements .. Write (nout,*) 'D01AQF Example Program Results' Allocate (w(lw),iw(liw)) epsabs = 0.0E0_nag_wp epsrel = 1.0E-04_nag_wp a = -1.0E0_nag_wp b = 1.0E0_nag_wp c = 0.5E0_nag_wp ifail = -1 Call d01aqf(g,a,b,c,epsabs,epsrel,result,abserr,w,lw,iw,liw,ifail) If (ifail>=0) Then Write (nout,*) Write (nout,99999) 'A ', 'lower limit of integration', a Write (nout,99999) 'B ', 'upper limit of integration', b Write (nout,99998) 'EPSABS', 'absolute accuracy requested', epsabs Write (nout,99998) 'EPSREL', 'relative accuracy requested', epsrel Write (nout,99998) 'C ', 'weight function parameter', c End If If (ifail>=0 .And. ifail<=3) Then Write (nout,*) Write (nout,99997) 'RESULT', 'approximation to the integral', result Write (nout,99998) 'ABSERR', 'estimate of the absolute error', abserr Write (nout,99996) 'IW(1) ', 'number of subintervals used', iw(1) End If 99999 Format (1X,A6,' - ',A32,' = ',F10.4) 99998 Format (1X,A6,' - ',A32,' = ',E9.2) 99997 Format (1X,A6,' - ',A32,' = ',F9.2) 99996 Format (1X,A6,' - ',A32,' = ',I4) End Program d01aqfe