Program f11xafe ! F11XAF Example Program Text ! Mark 24 Release. NAG Copyright 2012. ! .. Use Statements .. Use nag_library, Only: f11xaf, nag_wp ! .. Implicit None Statement .. Implicit None ! .. Parameters .. Integer, Parameter :: nin = 5, nout = 6 ! .. Local Scalars .. Integer :: i, ifail, n, nnz Character (1) :: check, trans ! .. Local Arrays .. Real (Kind=nag_wp), Allocatable :: a(:), x(:), y(:) Integer, Allocatable :: icol(:), irow(:) ! .. Executable Statements .. Write (nout,*) 'F11XAF 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 Allocate (a(nnz),x(n),y(n),icol(nnz),irow(nnz)) ! Read the matrix A Do i = 1, nnz Read (nin,*) a(i), irow(i), icol(i) End Do ! Read the vector x Read (nin,*) x(1:n) ! Calculate matrix-vector product trans = 'N' check = 'C' ! ifail: behaviour on error exit ! =0 for hard exit, =1 for quiet-soft, =-1 for noisy-soft ifail = 0 Call f11xaf(trans,n,nnz,a,irow,icol,check,x,y,ifail) ! Output results Write (nout,*) Write (nout,*) ' Matrix-vector product' Write (nout,'(E16.4)') y(1:n) ! Calculate transposed matrix-vector product trans = 'T' check = 'N' ifail = 0 Call f11xaf(trans,n,nnz,a,irow,icol,check,x,y,ifail) ! Output results Write (nout,*) Write (nout,*) ' Transposed matrix-vector product' Write (nout,'(E16.4)') y(1:n) End Program f11xafe