Program f08ysfe ! F08YSF Example Program Text ! Mark 24 Release. NAG Copyright 2012. ! .. Use Statements .. Use nag_library, Only: f06uaf, nag_wp, x02ajf, x04dbf, zggsvp, ztgsja ! .. Implicit None Statement .. Implicit None ! .. Parameters .. Integer, Parameter :: nin = 5, nout = 6 ! .. Local Scalars .. Real (Kind=nag_wp) :: eps, tola, tolb Integer :: i, ifail, info, irank, j, k, l, lda, & ldb, ldq, ldu, ldv, m, n, ncycle, p ! .. Local Arrays .. Complex (Kind=nag_wp), Allocatable :: a(:,:), b(:,:), q(:,:), tau(:), & u(:,:), v(:,:), work(:) Real (Kind=nag_wp), Allocatable :: alpha(:), beta(:), rwork(:) Integer, Allocatable :: iwork(:) Character (1) :: clabs(1), rlabs(1) ! .. Intrinsic Procedures .. Intrinsic :: max, real ! .. Executable Statements .. Write (nout,*) 'F08YSF Example Program Results' Write (nout,*) Flush (nout) ! Skip heading in data file Read (nin,*) Read (nin,*) m, n, p lda = m ldb = p ldq = n ldu = m ldv = p Allocate (a(lda,n),b(ldb,n),q(ldq,n),tau(n),u(ldu,m),v(ldv,p), & work(m+3*n+p),alpha(n),beta(n),rwork(2*n),iwork(n)) ! Read the m by n matrix A and p by n matrix B from data file Read (nin,*)(a(i,1:n),i=1,m) Read (nin,*)(b(i,1:n),i=1,p) ! Compute tola and tolb as ! tola = max(m,n)*norm(A)*macheps ! tolb = max(p,n)*norm(B)*macheps eps = x02ajf() tola = real(max(m,n),kind=nag_wp)*f06uaf('One-norm',m,n,a,lda,rwork)*eps tolb = real(max(p,n),kind=nag_wp)*f06uaf('One-norm',p,n,b,ldb,rwork)*eps ! Compute the factorization of (A, B) ! (A = U1*S*(Q1**H), B = V1*T*(Q1**H)) ! The NAG name equivalent of zggsvp is f08vsf Call zggsvp('U','V','Q',m,p,n,a,lda,b,ldb,tola,tolb,k,l,u,ldu,v,ldv,q, & ldq,iwork,rwork,tau,work,info) ! Compute the generalized singular value decomposition of (A, B) ! (A = U*D1*(0 R)*(Q**H), B = V*D2*(0 R)*(Q**H)) ! The NAG name equivalent of ztgsja is f08ysf Call ztgsja('U','V','Q',m,p,n,k,l,a,lda,b,ldb,tola,tolb,alpha,beta,u, & ldu,v,ldv,q,ldq,work,ncycle,info) If (info==0) Then ! Print solution irank = k + l Write (nout,*) 'Number of infinite generalized singular values (K)' Write (nout,99999) k Write (nout,*) 'Number of finite generalized singular values (L)' Write (nout,99999) l Write (nout,*) ' Effective Numerical rank of (A**T B**T)**T (K+L)' Write (nout,99999) irank Write (nout,*) Write (nout,*) 'Finite generalized singular values' Write (nout,99998)(alpha(j)/beta(j),j=k+1,irank) Write (nout,*) Flush (nout) ! ifail: behaviour on error exit ! =0 for hard exit, =1 for quiet-soft, =-1 for noisy-soft ifail = 0 Call x04dbf('General',' ',m,m,u,ldu,'Bracketed','1P,E12.4', & 'Orthogonal matrix U','Integer',rlabs,'Integer',clabs,80,0,ifail) Write (nout,*) Flush (nout) Call x04dbf('General',' ',p,p,v,ldv,'Bracketed','1P,E12.4', & 'Orthogonal matrix V','Integer',rlabs,'Integer',clabs,80,0,ifail) Write (nout,*) Flush (nout) Call x04dbf('General',' ',n,n,q,ldq,'Bracketed','1P,E12.4', & 'Orthogonal matrix Q','Integer',rlabs,'Integer',clabs,80,0,ifail) Write (nout,*) Flush (nout) Call x04dbf('Upper triangular','Non-unit',irank,irank,a(1,n-irank+1), & lda,'Bracketed','1P,E12.4','Non singular upper triangular matrix R', & 'Integer',rlabs,'Integer',clabs,80,0,ifail) Write (nout,*) Write (nout,*) 'Number of cycles of the Kogbetliantz method' Write (nout,99999) ncycle Else Write (nout,99997) 'Failure in ZTGSJA. INFO =', info End If 99999 Format (1X,I5) 99998 Format (3X,8(1P,E12.4)) 99997 Format (1X,A,I4) End Program f08ysfe