Program f08yvfe ! F08YVF Example Program Text ! Mark 24 Release. NAG Copyright 2012. ! .. Use Statements .. Use nag_library, Only: nag_wp, x04dbf, ztgsyl ! .. Implicit None Statement .. Implicit None ! .. Parameters .. Integer, Parameter :: nin = 5, nout = 6 ! .. Local Scalars .. Real (Kind=nag_wp) :: dif, scale Integer :: i, ifail, ijob, info, lda, ldb, ldc, & ldd, lde, ldf, lwork, m, n ! .. Local Arrays .. Complex (Kind=nag_wp), Allocatable :: a(:,:), b(:,:), c(:,:), d(:,:), & e(:,:), f(:,:), work(:) Integer, Allocatable :: iwork(:) Character (1) :: clabs(1), rlabs(1) ! .. Executable Statements .. Write (nout,*) 'F08YVF Example Program Results' Write (nout,*) Flush (nout) ! Skip heading in data file Read (nin,*) Read (nin,*) m, n lda = m ldb = n ldc = m ldd = m lde = n ldf = m lwork = 1 Allocate (a(lda,m),b(ldb,n),c(ldc,n),d(ldd,m),e(lde,n),f(ldf,n), & work(lwork),iwork(m+n+2)) ! Read A, B, D, E, C and F from data file Read (nin,*)(a(i,1:m),i=1,m) Read (nin,*)(b(i,1:n),i=1,n) Read (nin,*)(d(i,1:m),i=1,m) Read (nin,*)(e(i,1:n),i=1,n) Read (nin,*)(c(i,1:n),i=1,m) Read (nin,*)(f(i,1:n),i=1,m) ! Solve the Sylvester equations ! A*R - L*B = scale*C and D*R - L*E = scale*F ! for R and L. ijob = 0 ! The NAG name equivalent of ztgsyl is f08yvf Call ztgsyl('No transpose',ijob,m,n,a,lda,b,ldb,c,ldc,d,ldd,e,lde,f,ldf, & scale,dif,work,lwork,iwork,info) If (info>=1) Then Write (nout,99999) Write (nout,*) Flush (nout) End If ! Print the solution matrices R and L ! ifail: behaviour on error exit ! =0 for hard exit, =1 for quiet-soft, =-1 for noisy-soft ifail = 0 Call x04dbf('General',' ',m,n,c,ldc,'Bracketed','F7.4', & 'Solution matrix R','Integer',rlabs,'Integer',clabs,80,0,ifail) Write (nout,*) Flush (nout) ifail = 0 Call x04dbf('General',' ',m,n,f,ldf,'Bracketed','F7.4', & 'Solution matrix L','Integer',rlabs,'Integer',clabs,80,0,ifail) Write (nout,*) Write (nout,99998) 'SCALE = ', scale 99999 Format (/' (A,D) and (B,E) have common or very close eigenval', & 'ues.'/' Perturbed values were used to solve the equations') 99998 Format (1X,A,1P,E10.2) End Program f08yvfe