NAG Library Manual, Mark 28.7
```    Program g13befe

!     G13BEF Example Program Text

!     Mark 28.7 Release. NAG Copyright 2022.

!     .. Use Statements ..
Use nag_library, Only: g13bef, nag_wp, x04abf, x04caf
!     .. Implicit None Statement ..
Implicit None
!     .. Parameters ..
Integer, Parameter               :: iset = 1, nin = 5, nout = 6
!     .. Local Scalars ..
Real (Kind=nag_wp)               :: d, s
Integer                          :: i, ifail, imwa, isttf, itc, iwa,     &
kef, kfc, kpriv, kzef, kzsp, ldcm,   &
ldxxy, nadv, ncg, ndf, ndv, nis,     &
nit, npara, nser, nsttf, nxxy
!     .. Local Arrays ..
Real (Kind=nag_wp), Allocatable  :: cm(:,:), para(:), res(:), sd(:),     &
sttf(:), wa(:), xxy(:,:)
Real (Kind=nag_wp)               :: zsp(4)
Integer                          :: mr(7)
Integer, Allocatable             :: mt(:,:), mwa(:)
!     .. Intrinsic Procedures ..
Intrinsic                        :: max, sum
!     .. Executable Statements ..
Write (nout,*) 'G13BEF Example Program Results'
Write (nout,*)

!     Skip heading in data file

Read (nin,*) kzef, kfc, nxxy, nser, kef, nit, kzsp, kpriv
If (kzsp/=0) Then
End If

!     Number of input series
nis = nser - 1

!     Set the advisory channel to NOUT for monitoring information
If (kpriv/=0) Then
End If

Allocate (mt(4,nser))

Do i = 1, nis
End Do

!     Calculate NPARA and various other quantities required
!     for calculate array sizes
npara = 0
ncg = 0
Do i = 1, nis
If (mt(4,i)>1) Then
npara = npara + mt(2,i) + mt(3,i)
ncg = ncg + sum(mt(1:3,i))
End If
End Do
npara = npara + mr(1) + mr(3) + mr(4) + mr(6) + nser

!     Calculate size of arrays
isttf = mr(4)*mr(7) + mr(2) + mr(5)*mr(7) + mr(3) +                      &
max(mr(1),mr(6)*mr(7)) + ncg
ldxxy = nxxy
ldcm = npara

imwa = 0
iwa = 0
Allocate (xxy(ldxxy,nser),para(npara),sd(npara),cm(ldcm,npara),          &
res(nxxy),sttf(isttf),wa(iwa),mwa(imwa))

!     Read in rest of data

ifail = -1
Call g13bef(mr,nser,mt,para,npara,kfc,nxxy,xxy,ldxxy,kef,nit,kzsp,zsp,   &
itc,sd,cm,ldcm,s,d,ndf,kzef,res,sttf,isttf,nsttf,wa,iwa,mwa,imwa,      &
kpriv,ifail)
If (ifail/=0) Then
If (ifail/=8 .And. ifail/=9) Then
Go To 100
End If
End If

!     Display results
Write (nout,99999) 'The number of iterations carried out is', itc
Write (nout,*)
If (ifail/=8 .And. ifail/=9) Then
Write (nout,*)                                                         &
'Final values of the parameters and their standard deviations'
Write (nout,*)
Write (nout,*) '   I            PARA(I)                 SD'
Write (nout,*)
Write (nout,99998)(i,para(i),sd(i),i=1,npara)
Write (nout,*)
Flush (nout)
ifail = 0
Call x04caf('General',' ',npara,npara,cm,ldcm,                         &
'The correlation matrix is',ifail)
End If
Write (nout,*)
Write (nout,*) 'The residuals and the z and n values are'
Write (nout,*)
If (nser>1) Then
Write (nout,*) '   I         RES(I)          z(t)           n(t)'
Else
Write (nout,*) '   I         RES(I)          n(t)'
End If
Write (nout,*)
ndv = nxxy - mr(2) - mr(5)*mr(7)
Do i = 1, nxxy
If (i<=ndv) Then
Write (nout,99997) i, res(i), xxy(i,1:nser)
Else
Write (nout,99996) i, xxy(i,1:nser)
End If
End Do
If (mr(2)/=0 .Or. mr(5)/=0) Then
Write (nout,*)
Write (nout,*)                                                         &
'** Note that the residuals relate to differenced values **'
End If
Write (nout,*)
Write (nout,99995) 'The state set consists of', nsttf, ' values'
Write (nout,*)
Write (nout,99994) sttf(1:nsttf)
Write (nout,*)
Write (nout,99999) 'The number of degrees of freedom is', ndf

100   Continue

99999 Format (1X,A,I4)
99998 Format (1X,I4,2F20.6)
99997 Format (1X,I4,2F15.3,11(1X,F14.3))
99996 Format (1X,I4,F30.3,11(1X,F14.3))
99995 Format (1X,A,I4,A)
99994 Format (1X,6F10.4)
End Program g13befe
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