Program f02xufe
! F02XUF Example Program Text
! Mark 25 Release. NAG Copyright 2014.
! .. 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