! E04GYF Example Program Text ! Mark 23 Release. NAG Copyright 2011. MODULE e04gyfe_mod ! E04GYF Example Program Module: ! Parameters and User-defined Routines ! .. Use Statements .. USE nag_library, ONLY : nag_wp ! .. Implicit None Statement .. IMPLICIT NONE ! .. Parameters .. INTEGER, PARAMETER :: m = 15, n = 3, nin = 5, & nout = 6, nt = 3 INTEGER, PARAMETER :: lw = 8*n + 2*n*n + 2*m*n + 3*m ! .. Local Arrays .. REAL (KIND=nag_wp) :: t(m,nt), y(m) CONTAINS SUBROUTINE lsfun2(m,n,xc,fvec,fjac,ldfjac,iuser,ruser) ! Routine to evaluate the residuals and their 1st derivatives. ! .. Implicit None Statement .. IMPLICIT NONE ! .. Scalar Arguments .. INTEGER, INTENT (IN) :: ldfjac, m, n ! .. Array Arguments .. REAL (KIND=nag_wp), INTENT (INOUT) :: fjac(ldfjac,n), ruser(*) REAL (KIND=nag_wp), INTENT (OUT) :: fvec(m) REAL (KIND=nag_wp), INTENT (IN) :: xc(n) INTEGER, INTENT (INOUT) :: iuser(*) ! .. Local Scalars .. REAL (KIND=nag_wp) :: denom, dummy INTEGER :: i ! .. Executable Statements .. DO i = 1, m denom = xc(2)*t(i,2) + xc(3)*t(i,3) fvec(i) = xc(1) + t(i,1)/denom - y(i) fjac(i,1) = 1.0_nag_wp dummy = -1.0_nag_wp/(denom*denom) fjac(i,2) = t(i,1)*t(i,2)*dummy fjac(i,3) = t(i,1)*t(i,3)*dummy END DO RETURN END SUBROUTINE lsfun2 END MODULE e04gyfe_mod PROGRAM e04gyfe ! E04GYF Example Main Program ! .. Use Statements .. USE nag_library, ONLY : e04gyf USE e04gyfe_mod, ONLY : lsfun2, lw, m, n, nag_wp, nin, nout, nt, t, y ! .. Implicit None Statement .. IMPLICIT NONE ! .. Local Scalars .. REAL (KIND=nag_wp) :: fsumsq INTEGER :: i, ifail ! .. Local Arrays .. REAL (KIND=nag_wp) :: ruser(1), w(lw), x(n) INTEGER :: iuser(1) ! .. Executable Statements .. WRITE (nout,*) 'E04GYF Example Program Results' ! Skip heading in data file READ (nin,*) ! Observations of TJ (J = 1, 2, ..., nt) are held in T(I, J) ! (I = 1, 2, ..., m) DO i = 1, m READ (nin,*) y(i), t(i,1:nt) END DO x(1:nt) = (/ 0.5_nag_wp, 1.0_nag_wp, 1.5_nag_wp/) ifail = -1 CALL e04gyf(m,n,lsfun2,x,fsumsq,w,lw,iuser,ruser,ifail) SELECT CASE (ifail) CASE (0,2:8,10:) WRITE (nout,*) WRITE (nout,99999) 'On exit, the sum of squares is', fsumsq WRITE (nout,99999) 'at the point', x(1:n) END SELECT 99999 FORMAT (1X,A,3F12.4) END PROGRAM e04gyfe