Program f02xufe

!     F02XUF Example Program Text

!     Mark 30.2 Release. NAG Copyright 2024.

!     .. Use Statements ..
      Use nag_library, Only: f02xuf, nag_wp, x04dbf
!     .. Implicit None Statement ..
      Implicit None
!     .. Parameters ..
      Integer, Parameter               :: nin = 5, nout = 6
!     .. Local Scalars ..
      Integer                          :: i, ifail, lcwork, lda, ldb, ldq,     &
                                          lrwork, n, ncolb
      Logical                          :: wantp, wantq
!     .. Local Arrays ..
      Complex (Kind=nag_wp), Allocatable :: a(:,:), b(:), cwork(:), q(:,:)
      Real (Kind=nag_wp), Allocatable  :: rwork(:), sv(:)
      Character (1)                    :: clabs(1), rlabs(1)
!     .. Intrinsic Procedures ..
      Intrinsic                        :: conjg
!     .. Executable Statements ..
      Write (nout,*) 'F02XUF Example Program Results'
      Write (nout,*)
      Flush (nout)
!     Skip heading in data file
      Read (nin,*)
      Read (nin,*) n, ncolb
      lcwork = n - 1
      lda = n
      ldb = n
      ldq = n
      lrwork = 5*(n-1)
      Allocate (a(lda,n),b(ldb),cwork(lcwork),q(ldq,n),rwork(lrwork),sv(n))
      Read (nin,*)(a(i,i:n),i=1,n)
      Read (nin,*) b(1:n)
!     Find the SVD of A.
      wantq = .True.
      wantp = .True.

!     ifail: behaviour on error exit
!             =0 for hard exit, =1 for quiet-soft, =-1 for noisy-soft
      ifail = 0
      Call f02xuf(n,a,lda,ncolb,b,ldb,wantq,q,ldq,sv,wantp,rwork,cwork,ifail)

      Write (nout,*) 'Singular value decomposition of A'
      Write (nout,*)
      Write (nout,*) 'Singular values'
      Write (nout,99999) sv(1:n)
      Write (nout,*)
      Flush (nout)

      ifail = 0
      Call x04dbf('General',' ',n,n,q,ldq,'Bracketed','F7.4',                  &
        'Left-hand singular vectors, by column','N',rlabs,'N',clabs,80,0,      &
        ifail)

      Write (nout,*)
      Write (nout,*) 'Right-hand singular vectors, by column'
      Do i = 1, n
        Write (nout,99998) conjg(a(1:n,i))
      End Do
      Write (nout,*)
      Write (nout,*) 'Vector conjg( Q'' )*B'
      Write (nout,99998) b(1:n)

99999 Format (1X,3F9.4)
99998 Format (3X,3('(',F7.4,',',F8.4,') ',:))
    End Program f02xufe