Program f08nnfe ! F08NNF Example Program Text ! Mark 24 Release. NAG Copyright 2012. ! .. Use Statements .. Use nag_library, Only: nag_wp, x04daf, zgeev ! .. Implicit None Statement .. Implicit None ! .. Parameters .. Integer, Parameter :: nb = 64, nin = 5, nout = 6 ! .. Local Scalars .. Integer :: i, ifail, info, lda, ldvr, lwork, n ! .. Local Arrays .. Complex (Kind=nag_wp), Allocatable :: a(:,:), vr(:,:), w(:), work(:) Complex (Kind=nag_wp) :: dummy(1,1) Real (Kind=nag_wp), Allocatable :: rwork(:) ! .. Intrinsic Procedures .. Intrinsic :: max, nint, real ! .. Executable Statements .. Write (nout,*) 'F08NNF Example Program Results' Write (nout,*) ! Skip heading in data file Read (nin,*) Read (nin,*) n lda = n ldvr = n Allocate (a(lda,n),vr(ldvr,n),w(n),rwork(2*n)) ! Use routine workspace query to get optimal workspace. lwork = -1 ! The NAG name equivalent of zgeev is f08nnf Call zgeev('No left vectors','Vectors (right)',n,a,lda,w,dummy,1,vr, & ldvr,dummy,lwork,rwork,info) ! Make sure that there is enough workspace for blocksize nb. lwork = max((nb+1)*n,nint(real(dummy(1,1)))) Allocate (work(lwork)) ! Read the matrix A from data file Read (nin,*)(a(i,1:n),i=1,n) ! Compute the eigenvalues and right eigenvectors of A ! The NAG name equivalent of zgeev is f08nnf Call zgeev('No left vectors','Vectors (right)',n,a,lda,w,dummy,1,vr, & ldvr,work,lwork,rwork,info) If (info==0) Then ! Print solution 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 x04daf('General',' ',n,n,vr,ldvr,'Eigenvectors',ifail) Else Write (nout,*) Write (nout,99998) 'Failure in ZGEEV. INFO = ', info End If 99999 Format ((3X,4(' (',F7.4,',',F7.4,')':))) 99998 Format (1X,A,I4) End Program f08nnfe