Program f07vgfe ! F07VGF Example Program Text ! Mark 24 Release. NAG Copyright 2012. ! .. Use Statements .. Use nag_library, Only: dtbcon, nag_wp, x02ajf ! .. Implicit None Statement .. Implicit None ! .. Parameters .. Integer, Parameter :: nin = 5, nout = 6 Character (1), Parameter :: diag = 'N', norm = '1' ! .. Local Scalars .. Real (Kind=nag_wp) :: rcond Integer :: i, info, j, kd, ldab, n Character (1) :: uplo ! .. Local Arrays .. Real (Kind=nag_wp), Allocatable :: ab(:,:), work(:) Integer, Allocatable :: iwork(:) ! .. Intrinsic Procedures .. Intrinsic :: max, min ! .. Executable Statements .. Write (nout,*) 'F07VGF Example Program Results' ! Skip heading in data file Read (nin,*) Read (nin,*) n, kd ldab = kd + 1 Allocate (ab(ldab,n),work(3*n),iwork(n)) ! Read A from data file Read (nin,*) uplo If (uplo=='U') Then Do i = 1, n Read (nin,*)(ab(kd+1+i-j,j),j=i,min(n,i+kd)) End Do Else If (uplo=='L') Then Do i = 1, n Read (nin,*)(ab(1+i-j,j),j=max(1,i-kd),i) End Do End If ! Estimate condition number ! The NAG name equivalent of dtbcon is f07vgf Call dtbcon(norm,uplo,diag,n,kd,ab,ldab,rcond,work,iwork,info) Write (nout,*) If (rcond>=x02ajf()) Then Write (nout,99999) 'Estimate of condition number =', & 1.0E0_nag_wp/rcond Else Write (nout,*) 'A is singular to working precision' End If 99999 Format (1X,A,1P,E10.2) End Program f07vgfe