! E01TNF Example Program Text ! Mark 23 Release. NAG Copyright 2011. MODULE e01tnfe_mod ! E01TNF Example Program Module: ! Parameters and User-defined Routines ! .. Use Statements .. USE nag_library, ONLY : nag_wp ! .. Implicit None Statement .. IMPLICIT NONE ! .. Parameters .. REAL (KIND=nag_wp), PARAMETER :: one = 1.0_nag_wp REAL (KIND=nag_wp), PARAMETER :: six = 6.0_nag_wp REAL (KIND=nag_wp), PARAMETER :: three = 3.0_nag_wp INTEGER, PARAMETER :: nin = 5, nout = 6 CONTAINS FUNCTION funct(x) ! This function evaluates the 5D function funct. ! .. Implicit None Statement .. IMPLICIT NONE ! .. Function Return Value .. REAL (KIND=nag_wp) :: funct ! .. Array Arguments .. REAL (KIND=nag_wp), INTENT (IN) :: x(5) ! .. Intrinsic Functions .. INTRINSIC cos ! .. Executable Statements .. funct = ((1.25_nag_wp+cos(5.4_nag_wp*x(5)))*cos(six*x(1))*cos(six*x( & 2))*cos(six*x(3)))/(six+six*(three*x(4)-one)**2) RETURN END FUNCTION funct END MODULE e01tnfe_mod PROGRAM e01tnfe ! E01TNF Example Main Program ! .. Use Statements .. USE nag_library, ONLY : e01tmf, e01tnf, g05kff, g05saf, nag_wp USE e01tnfe_mod, ONLY : funct, nin, nout ! .. Implicit None Statement .. IMPLICIT NONE ! .. Parameters .. INTEGER, PARAMETER :: lseed = 1 ! .. Local Scalars .. REAL (KIND=nag_wp) :: fun INTEGER :: genid, i, ifail, liq, lrq, & lstate, m, n, nq, nw, subid ! .. Local Arrays .. REAL (KIND=nag_wp), ALLOCATABLE :: f(:), q(:), qx(:,:), rq(:), & x(:,:), xe(:,:) INTEGER, ALLOCATABLE :: iq(:), state(:) INTEGER :: seed(lseed), seed2(lseed) ! .. Intrinsic Functions .. INTRINSIC abs ! .. Executable Statements .. WRITE (nout,*) 'E01TNF Example Program Results' ! Skip heading in data file READ (nin,*) ! Read in the base generator information and seeds READ (nin,*) genid, subid, seed(1), seed2(1) ! Initial call to initialiser to get size of STATE array lstate = 0 ALLOCATE (state(lstate)) ifail = 0 CALL g05kff(genid,subid,seed,lseed,state,lstate,ifail) ! Reallocate STATE DEALLOCATE (state) ALLOCATE (state(lstate)) ! Initialize the generator to a repeatable sequence ifail = 0 CALL g05kff(genid,subid,seed,lseed,state,lstate,ifail) ! Input the number of nodes. READ (nin,*) m liq = 2*m + 1 lrq = 21*m + 11 ALLOCATE (x(5,m),f(m),iq(liq),rq(lrq)) ! Generate the data points X ifail = 0 CALL g05saf(5*m,state,x,ifail) ! Evaluate F DO i = 1, m f(i) = funct(x(1,i)) END DO ! Generate the interpolant using E01TMF. nq = 0 nw = 0 ifail = 0 CALL e01tmf(m,x,f,nw,nq,iq,rq,ifail) ! Input the number of evaluation points. READ (nin,*) n ALLOCATE (xe(5,n),q(n),qx(5,n)) ! Generate repeatable evaluation points. ifail = 0 CALL g05kff(genid,subid,seed2,lseed,state,lstate,ifail) ifail = 0 CALL g05saf(5*n,state,xe,ifail) ! Evaluate the interpolant. ifail = 0 CALL e01tnf(m,x,f,iq,rq,n,xe,q,qx,ifail) WRITE (nout,99997) WRITE (nout,99998) DO i = 1, n fun = funct(xe(1,i)) WRITE (nout,99999) i, fun, q(i), abs(fun-q(i)) END DO 99999 FORMAT (1X,I4,1X,3F10.4) 99998 FORMAT (4X,'---|',20('-'),'+',15('-')) 99997 FORMAT (/4X,'I |',2X,'F(I)',6X,'Q(I)',4X,'|',1X,'|F(I)-Q(I)|') END PROGRAM e01tnfe