Program f11defe ! F11DEF Example Program Text ! Mark 24 Release. NAG Copyright 2012. ! .. Use Statements .. Use nag_library, Only: f11def, nag_wp ! .. Implicit None Statement .. Implicit None ! .. Parameters .. Integer, Parameter :: nin = 5, nout = 6 ! .. Local Scalars .. Real (Kind=nag_wp) :: omega, rnorm, tol Integer :: i, ifail, itn, l, lwork, m, maxitn, & n, nnz Character (8) :: method Character (1) :: precon ! .. Local Arrays .. Real (Kind=nag_wp), Allocatable :: a(:), b(:), work(:), x(:) Integer, Allocatable :: icol(:), irow(:), iwork(:) ! .. Intrinsic Procedures .. Intrinsic :: max ! .. Executable Statements .. Write (nout,*) 'F11DEF Example Program Results' Write (nout,*) ! Skip heading in data file Read (nin,*) ! Read algorithmic parameters Read (nin,*) n, m Read (nin,*) nnz Read (nin,*) method, precon l = n If (precon=='N' .Or. precon=='n') l = 0 lwork = max(4*n+m*(m+n+5)+l+101,8*n+l+100,2*n*(m+3)+m*(m+2)+l+100, & 11*n+l+100) Allocate (a(nnz),b(n),work(lwork),x(n),icol(nnz),irow(nnz),iwork(2*n+1)) Read (nin,*) omega Read (nin,*) tol, maxitn ! Read the matrix A Do i = 1, nnz Read (nin,*) a(i), irow(i), icol(i) End Do ! Read right-hand side vector b and initial approximate solution x Read (nin,*) b(1:n) Read (nin,*) x(1:n) ! Solve Ax = b using F11DEF ! ifail: behaviour on error exit ! =0 for hard exit, =1 for quiet-soft, =-1 for noisy-soft ifail = 0 Call f11def(method,precon,n,nnz,a,irow,icol,omega,b,m,tol,maxitn,x, & rnorm,itn,work,lwork,iwork,ifail) Write (nout,'(A,I10,A)') ' Converged in', itn, ' iterations' Write (nout,'(A,1P,E16.3)') ' Final residual norm =', rnorm Write (nout,*) ! Output x Write (nout,*) ' X' Write (nout,'(1X,1P,E16.4)') x(1:n) End Program f11defe