! E04YAF Example Program Text ! Mark 24 Release. NAG Copyright 2012. Module e04yafe_mod ! E04YAF Example Program Module: ! Parameters and User-defined Routines ! .. Use Statements .. Use nag_library, Only: nag_wp ! .. Implicit None Statement .. Implicit None ! .. Parameters .. Integer, Parameter :: liw = 1, mdec = 15, ndec = 3, & nin = 5, nout = 6 Integer, Parameter :: ldfjac = mdec Integer, Parameter :: lw = 3*ndec + mdec + mdec*ndec ! .. Local Arrays .. Real (Kind=nag_wp) :: t(mdec,ndec), y(mdec) Contains Subroutine lsqfun(iflag,m,n,xc,fvec,fjac,ldfjac,iw,liw,w,lw) ! Routine to evaluate the residuals and their 1st derivatives ! .. Scalar Arguments .. Integer, Intent (Inout) :: iflag Integer, Intent (In) :: ldfjac, liw, lw, m, n ! .. Array Arguments .. Real (Kind=nag_wp), Intent (Inout) :: fjac(ldfjac,n), w(lw) Real (Kind=nag_wp), Intent (Out) :: fvec(m) Real (Kind=nag_wp), Intent (In) :: xc(n) Integer, Intent (Inout) :: iw(liw) ! .. 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) If (iflag/=1) Then fvec(i) = xc(1) + t(i,1)/denom - y(i) End If If (iflag/=0) Then fjac(i,1) = 1.0E0_nag_wp dummy = -1.0E0_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 If End Do Return End Subroutine lsqfun End Module e04yafe_mod Program e04yafe ! E04YAF Example Main Program ! .. Use Statements .. Use nag_library, Only: e04yaf, nag_wp Use e04yafe_mod, Only: ldfjac, liw, lsqfun, lw, mdec, ndec, nin, nout, & t, y ! .. Implicit None Statement .. Implicit None ! .. Local Scalars .. Integer :: i, ifail, m, n ! .. Local Arrays .. Real (Kind=nag_wp) :: fjac(ldfjac,ndec), fvec(mdec), & w(lw), x(ndec) Integer :: iw(liw) ! .. Executable Statements .. Write (nout,*) 'E04YAF Example Program Results' ! Skip heading in data file Read (nin,*) n = ndec m = mdec ! Observations of TJ (J = 1, 2, ..., n) are held in T(I, J) ! (I = 1, 2, ..., m) Do i = 1, m Read (nin,*) y(i), t(i,1:n) End Do ! Set up an arbitrary point at which to check the 1st ! derivatives x(1:n) = (/0.19E0_nag_wp,-1.34E0_nag_wp,0.88E0_nag_wp/) Write (nout,*) Write (nout,*) 'The test point is' Write (nout,99999) x(1:n) ifail = -1 Call e04yaf(m,n,lsqfun,x,fvec,fjac,ldfjac,iw,liw,w,lw,ifail) If (ifail>=0 .And. ifail/=1) Then Select Case (ifail) Case (0) Write (nout,*) Write (nout,*) '1st derivatives are consistent with residual values' Case (2) Write (nout,*) Write (nout,*) 'Probable error in calculation of 1st derivatives' End Select Write (nout,*) Write (nout,*) 'At the test point, LSQFUN gives' Write (nout,*) Write (nout,*) ' Residuals 1st derivatives' Write (nout,99998)(fvec(i),fjac(i,1:n),i=1,m) End If 99999 Format (1X,4F10.5) 99998 Format (1X,1P,4E15.3) End Program e04yafe