```    Program f08aafe

!     F08AAF Example Program Text

!     Mark 26.2 Release. NAG Copyright 2017.

!     .. Use Statements ..
Use nag_library, Only: dgels, dnrm2, nag_wp
!     .. Implicit None Statement ..
Implicit None
!     .. Parameters ..
Integer, Parameter               :: nb = 64, nin = 5, nout = 6
!     .. Local Scalars ..
Real (Kind=nag_wp)               :: rnorm
Integer                          :: i, info, lda, ldb, lwork, m, n, nrhs
!     .. Local Arrays ..
Real (Kind=nag_wp), Allocatable  :: a(:,:), b(:), work(:)
!     .. Executable Statements ..
Write (nout,*) 'F08AAF Example Program Results'
Write (nout,*)
!     Skip heading in data file
lda = m
lwork = n + nb*m
Allocate (a(lda,n),b(m),work(lwork))

!     Read A and B from data file

!     Solve the least squares problem min( norm2(b - Ax) ) for x

nrhs = 1
ldb = m

!     The NAG name equivalent of dgels is f08aaf
Call dgels('No transpose',m,n,nrhs,a,lda,b,ldb,work,lwork,info)

!     Print solution

Write (nout,*) 'Least squares solution'
Write (nout,99999) b(1:n)

!     Compute and print estimate of the square root of the residual
!     sum of squares

!     The NAG name equivalent of dnrm2 is f06ejf
rnorm = dnrm2(m-n,b(n+1),1)
Write (nout,*)
Write (nout,*) 'Square root of the residual sum of squares'
Write (nout,99998) rnorm

99999 Format (1X,7F11.4)
99998 Format (3X,1P,E11.2)
End Program f08aafe
```