Program f11jbfe ! F11JBF Example Program Text ! Mark 24 Release. NAG Copyright 2012. ! .. Use Statements .. Use nag_library, Only: f11jaf, f11jbf, nag_wp ! .. Implicit None Statement .. Implicit None ! .. Parameters .. Integer, Parameter :: nin = 5, nout = 6 ! .. Local Scalars .. Real (Kind=nag_wp) :: dscale, dtol Integer :: i, ifail, la, lfill, liwork, n, nnz, & nnzc, npivm Character (1) :: check, mic, pstrat ! .. Local Arrays .. Real (Kind=nag_wp), Allocatable :: a(:), x(:), y(:) Integer, Allocatable :: icol(:), ipiv(:), irow(:), istr(:), & iwork(:) ! .. Executable Statements .. Write (nout,*) 'F11JBF Example Program Results' ! Skip heading in data file Read (nin,*) ! Read order of matrix and number of non-zero entries Read (nin,*) n Read (nin,*) nnz la = 3*nnz liwork = 2*la + 7*n + 1 Allocate (a(la),x(n),y(n),icol(la),ipiv(n),irow(la),istr(n+1), & iwork(liwork)) ! Read the matrix A Do i = 1, nnz Read (nin,*) a(i), irow(i), icol(i) End Do ! Read the vector y Read (nin,*) y(1:n) ! Calculate Cholesky factorization lfill = -1 dtol = 0.0E0_nag_wp mic = 'N' dscale = 0.0E0_nag_wp pstrat = 'M' ! ifail: behaviour on error exit ! =0 for hard exit, =1 for quiet-soft, =-1 for noisy-soft ifail = 0 Call f11jaf(n,nnz,a,la,irow,icol,lfill,dtol,mic,dscale,pstrat,ipiv,istr, & nnzc,npivm,iwork,liwork,ifail) ! Check the output value of NPIVM If (npivm/=0) Then Write (nout,*) 'Factorization is not complete' Else ! Solve P L D L^T P^T x = y check = 'C' ifail = 0 Call f11jbf(n,a,la,irow,icol,ipiv,istr,check,y,x,ifail) ! Output results Write (nout,*) ' Solution of linear system' Write (nout,99999) x(1:n) End If 99999 Format (1X,E16.4) End Program f11jbfe