Program f08fcfe ! F08FCF Example Program Text ! Mark 24 Release. NAG Copyright 2012. ! .. Use Statements .. Use nag_library, Only: dsyevd, nag_wp, x04caf ! .. Implicit None Statement .. Implicit None ! .. Parameters .. Integer, Parameter :: nin = 5, nout = 6 ! .. Local Scalars .. Integer :: i, ifail, info, lda, liwork, lwork, n Character (1) :: job, uplo ! .. Local Arrays .. Real (Kind=nag_wp), Allocatable :: a(:,:), w(:), work(:) Integer, Allocatable :: iwork(:) ! .. Executable Statements .. Write (nout,*) 'F08FCF Example Program Results' ! Skip heading in data file Read (nin,*) Read (nin,*) n lda = n liwork = 5*n + 3 lwork = 2*n*n + 6*n + 1 Allocate (a(lda,n),w(n),work(lwork),iwork(liwork)) ! Read A from data file Read (nin,*) uplo If (uplo=='U') Then Read (nin,*)(a(i,i:n),i=1,n) Else If (uplo=='L') Then Read (nin,*)(a(i,1:i),i=1,n) End If Read (nin,*) job ! Calculate all the eigenvalues and eigenvectors of A ! The NAG name equivalent of dsyevd is f08fcf Call dsyevd(job,uplo,n,a,lda,w,work,lwork,iwork,liwork,info) Write (nout,*) If (info>0) Then Write (nout,*) 'Failure to converge.' Else ! Print eigenvalues and eigenvectors Write (nout,*) 'Eigenvalues' Write (nout,99999) w(1:n) Write (nout,*) Flush (nout) ! ifail: behaviour on error exit ! =0 for hard exit, =1 for quiet-soft, =-1 for noisy-soft ifail = 0 Call x04caf('General',' ',n,n,a,lda,'Eigenvectors',ifail) End If 99999 Format (3X,(8F8.4)) End Program f08fcfe