```    Program e01aefe

!     E01AEF Example Program Text

!     Mark 27.0 Release. NAG Copyright 2019.

!     .. Use Statements ..
Use nag_library, Only: e01aef, f16dnf, nag_wp, x02ajf
!     .. Implicit None Statement ..
Implicit None
!     .. Parameters ..
Integer, Parameter               :: nin = 5, nout = 6
!     .. Local Scalars ..
Real (Kind=nag_wp)               :: restol, xmax, xmin
Integer                          :: i, ifail, ipmax, ires, itmax, itmin, &
iy, j, k, liwrk, lwrk, m, n
!     .. Local Arrays ..
Real (Kind=nag_wp), Allocatable  :: a(:), wrk(:), x(:), y(:)
Integer, Allocatable             :: ip(:), iwrk(:)
!     .. Intrinsic Procedures ..
Intrinsic                        :: abs, sum
!     .. Executable Statements ..
Write (nout,*) 'E01AEF Example Program Results'

!     Skip heading in data file

itmin = -1
itmax = -1

liwrk = 2*(m+1)
Allocate (ip(m),x(m),iwrk(liwrk))

n = m + sum(ip(1:m))

!     Get the maximum value of IP

Call f16dnf(m,ip,1,k,ipmax)

lwrk = 7*n + 5*ipmax + m + 7
Allocate (a(n),y(n),wrk(lwrk))

j = 0

Do i = 1, m
j = j + ip(i) + 1
End Do

ifail = -1
Call e01aef(m,xmin,xmax,x,y,ip,n,itmin,itmax,a,wrk,lwrk,iwrk,liwrk,      &
ifail)

Write (nout,*)

Select Case (ifail)
Case (0,4:)
Write (nout,99999) 'Total number of interpolating conditions =', n
Write (nout,*)
Write (nout,*) 'Interpolating polynomial'
Write (nout,*)
Write (nout,*) '   i                a_i'

Do i = 0, n - 1
Write (nout,99998) i, a(i+1)
End Do

Write (nout,*)
Write (nout,*) '  i   x_i    order(k)   y^(k)    Residual'

!       Residuals less than 100 times machine precision are not printed.
restol = x02ajf()*100.0_nag_wp
iy = 0
ires = ipmax + 1

Do i = 1, m

iy = iy + 1
ires = ires + 1
If (abs(wrk(ires))>restol) Then
Write (nout,99996) i, x(i), 0, y(iy), wrk(ires)
Else
Write (nout,99995) i, x(i), 0, y(iy), ' - '
End If
Do j = 1, ip(i)
iy = iy + 1
ires = ires + 1
If (abs(wrk(ires))>restol) Then
Write (nout,99997) j, y(iy), wrk(ires)
Else
Write (nout,99994) j, y(iy), ' - '
End If
End Do

End Do

End Select

99999 Format (1X,A,I4)
99998 Format (1X,I4,F20.4)
99997 Format (10X,I7,F11.1,E19.10)
99996 Format (1X,I3,F6.1,I7,F11.1,E19.10)
99995 Format (1X,I3,F6.1,I7,F11.1,A11)
99994 Format (10X,I7,F11.1,A11)
End Program e01aefe
```