NAG Library Manual, Mark 29.3
Interfaces:  FL   CL   CPP   AD
```    Program g02gnfe

!     G02GNF Example Program Text

!     Mark 29.3 Release. NAG Copyright 2023.

!     .. Use Statements ..
Use nag_library, Only: g02gcf, g02gnf, nag_wp
!     .. Implicit None Statement ..
Implicit None
!     .. Parameters ..
Integer, Parameter               :: nin = 5, nout = 6
!     .. Local Scalars ..
Real (Kind=nag_wp)               :: a, dev, eps, sestat, stat, tol, z
Integer                          :: i, idf, ifail, ip, iprint, irank,    &
ldv, ldx, lwk, lwt, m, maxit, n
Logical                          :: est
Character (1)                    :: link, mean, offset, weight
!     .. Local Arrays ..
Real (Kind=nag_wp), Allocatable  :: b(:), cov(:), f(:), se(:), v(:,:),   &
wk(:), wt(:), x(:,:), y(:)
Integer, Allocatable             :: isx(:)
!     .. Intrinsic Procedures ..
Intrinsic                        :: count, max
!     .. Executable Statements ..
Write (nout,*) 'G02GNF Example Program Results'
Write (nout,*)

!     Skip heading in data file

!     Read in the problem size
Read (nin,*) link, mean, offset, weight, n, m

If (weight=='W' .Or. weight=='w') Then
lwt = n
Else
lwt = 0
End If
ldx = n
Allocate (x(ldx,m),y(n),wt(lwt),isx(m))

!     Read in data
If (lwt>0) Then
Else
End If

!     Read in variable inclusion flags

!     Calculate IP
ip = count(isx(1:m)>0)
If (mean=='M' .Or. mean=='m') Then
ip = ip + 1
End If

!     Read in power for exponential link
End If

ldv = n
lwk = max((ip*ip+3*ip+22)/2,ip)
Allocate (b(ip),se(ip),cov(ip*(ip+1)/2),v(ldv,ip+7),wk(lwk),f(ip))

!     Read in the offset
If (offset=='Y' .Or. offset=='y') Then
End If

!     Read in control parameters
Read (nin,*) iprint, eps, tol, maxit

!     Fit generalized linear model with Poisson errors
ifail = -1
Call g02gcf('L','M','N','U',n,x,ldx,m,isx,ip,y,wt,a,dev,idf,b,irank,se,  &
cov,v,ldv,tol,maxit,iprint,eps,wk,ifail)
If (ifail/=0) Then
If (ifail<7) Then
Go To 100
End If
End If

!     Display initial results
Write (nout,99999) 'Deviance = ', dev
Write (nout,99998) 'Degrees of freedom = ', idf
Write (nout,*)
Write (nout,*) '      Estimate     Standard error'
Write (nout,*)
Write (nout,99997)(b(i),se(i),i=1,ip)

!     Estimate the estimable functions
i = 0
fun_lp: Do
!       Read in the function
If (ifail/=0) Then
Exit fun_lp
End If

i = i + 1

!       Estimate it
ifail = -1
Call g02gnf(ip,irank,b,cov,v,ldv,f,est,stat,sestat,z,tol,wk,ifail)
If (ifail/=0) Then
If (ifail/=2) Then
Go To 100
End If
End If

!       Display results
Write (nout,*)
Write (nout,99996) 'Function ', i
Write (nout,99995) f(1:ip)
Write (nout,*)
If (est) Then
Write (nout,99994) 'STAT = ', stat, ' SE = ', sestat, ' Z = ', z
Else
Write (nout,*) 'Function not estimable'
End If
End Do fun_lp

100   Continue

99999 Format (1X,A,E12.4)
99998 Format (1X,A,I2)
99997 Format (1X,2F14.4)
99996 Format (1X,A,I4)
99995 Format (1X,5F8.2)
99994 Format (1X,A,F10.4,A,F10.4,A,F10.4)
End Program g02gnfe
```