Program f07bdfe ! F07BDF Example Program Text ! Mark 24 Release. NAG Copyright 2012. ! .. Use Statements .. Use nag_library, Only: dgbtrf, nag_wp, x04cef ! .. Implicit None Statement .. Implicit None ! .. Parameters .. Integer, Parameter :: nin = 5, nout = 6 ! .. Local Scalars .. Integer :: i, ifail, info, j, k, kl, ku, ldab, & m, n ! .. Local Arrays .. Real (Kind=nag_wp), Allocatable :: ab(:,:) Integer, Allocatable :: ipiv(:) ! .. Intrinsic Procedures .. Intrinsic :: max, min ! .. Executable Statements .. Write (nout,*) 'F07BDF Example Program Results' ! Skip heading in data file Read (nin,*) Read (nin,*) m, n, kl, ku ldab = 2*kl + ku + 1 Allocate (ab(ldab,n),ipiv(n)) ! Read A from data file k = kl + ku + 1 Read (nin,*)((ab(k+i-j,j),j=max(i-kl,1),min(i+ku,n)),i=1,m) ! Factorize A ! The NAG name equivalent of dgbtrf is f07bdf Call dgbtrf(m,n,kl,ku,ab,ldab,ipiv,info) ! Print details of factorization Write (nout,*) Flush (nout) ! ifail: behaviour on error exit ! =0 for hard exit, =1 for quiet-soft, =-1 for noisy-soft ifail = 0 Call x04cef(m,n,kl,kl+ku,ab,ldab,'Details of factorization',ifail) ! Print pivot indices Write (nout,*) Write (nout,*) 'IPIV' Write (nout,99999) ipiv(1:min(m,n)) If (info/=0) Write (nout,*) 'The factor U is singular' 99999 Format ((3X,7I11)) End Program f07bdfe