Program f11mgfe
! F11MGF Example Program Text
! Mark 30.1 Release. NAG Copyright 2024.
! .. Use Statements ..
Use nag_library, Only: f11mdf, f11mef, f11mgf, f11mlf, nag_wp
! .. Implicit None Statement ..
Implicit None
! .. Parameters ..
Real (Kind=nag_wp), Parameter :: one = 1.E0_nag_wp
Integer, Parameter :: nin = 5, nout = 6
! .. Local Scalars ..
Real (Kind=nag_wp) :: anorm, flop, rcond, thresh
Integer :: i, ifail, n, nnz, nnzl, nnzu, nzlmx, &
nzlumx, nzumx
Character (1) :: norm, spec
! .. Local Arrays ..
Real (Kind=nag_wp), Allocatable :: a(:), lval(:), uval(:)
Integer, Allocatable :: icolzp(:), il(:), iprm(:), &
irowix(:), iu(:)
! .. Executable Statements ..
Write (nout,*) 'F11MGF Example Program Results'
! Skip heading in data file
Read (nin,*)
! Read order of matrix
Read (nin,*) n
Allocate (icolzp(n+1),iprm(7*n))
! Read the matrix A
Read (nin,*) icolzp(1:n+1)
nnz = icolzp(n+1) - 1
Allocate (a(nnz),lval(8*nnz),uval(8*nnz),il(7*n+8*nnz+4),irowix(nnz), &
iu(2*n+8*nnz+1))
Do i = 1, nnz
Read (nin,*) a(i), irowix(i)
End Do
! Calculate COLAMD permutation
spec = 'M'
! ifail: behaviour on error exit
! =0 for hard exit, =1 for quiet-soft, =-1 for noisy-soft
ifail = 0
Call f11mdf(spec,n,icolzp,irowix,iprm,ifail)
! Factorise
thresh = one
ifail = 0
nzlmx = 8*nnz
nzlumx = 8*nnz
nzumx = 8*nnz
Call f11mef(n,irowix,a,iprm,thresh,nzlmx,nzlumx,nzumx,il,lval,iu,uval, &
nnzl,nnzu,flop,ifail)
! Calculate norm
norm = '1'
ifail = 0
Call f11mlf(norm,anorm,n,icolzp,irowix,a,ifail)
! Calculate condition number
ifail = 0
Call f11mgf(norm,n,il,lval,iu,uval,anorm,rcond,ifail)
! Output result
Write (nout,*)
Write (nout,*) 'Norm ,Condition number'
Write (nout,'(F7.3,A1,F7.3)') anorm, ',', 1.0E0_nag_wp/rcond
End Program f11mgfe