Program f08me_p0w_fe
! F08ME_P0W_F Example Program Text
! Mark 30.1 Release. NAG Copyright 2024.
! .. Use Statements ..
Use iso_c_binding, Only: c_ptr
Use nagad_library, Only: f08me_p0w_f
Use nag_library, Only: nag_wp, x04caf
! .. Implicit None Statement ..
Implicit None
! .. Parameters ..
Integer, Parameter :: nin = 5, nout = 6
! .. Local Scalars ..
Type (c_ptr) :: ad_handle
Integer :: i, ifail, ldc, ldu, ldvt, n
Character (1) :: uplo
! .. Local Arrays ..
Real (Kind=nag_wp), Allocatable :: c(:,:), d(:), e(:), u(:,:), vt(:,:), &
work(:)
! .. Executable Statements ..
Write (nout,*) 'F08ME_P0W_F Example Program Results'
! Skip heading in data file
Read (nin,*)
Read (nin,*) n
ldc = 1
ldu = n
ldvt = n
Allocate (c(ldc,1),d(n),e(n-1),u(ldu,n),vt(ldvt,n),work(4*n))
! Read B from data file as d and e
Read (nin,*) d(1:n)
Read (nin,*) e(1:n-1)
Read (nin,*) uplo
! Initialize U and VT to be the unit matrix
u = 0.0_nag_wp
vt = 0.0_nag_wp
Do i = 1, n
u(i,i) = 1.0_nag_wp
vt(i,i) = 1.0_nag_wp
End Do
! Calculate the SVD of B
ifail = 0
Call f08me_p0w_f(ad_handle,uplo,n,n,n,0,d,e,u,ldu,vt,ldvt,c,ldc,work, &
ifail)
Write (nout,*)
! Print singular values, left & right singular vectors
Write (nout,*) 'Singular values'
Write (nout,99999) d(1:n)
Write (nout,*)
Flush (nout)
ifail = 0
Call x04caf('General',' ',n,n,u,ldu,'Left singular vectors, by column', &
ifail)
Write (nout,*)
Flush (nout)
ifail = 0
Call x04caf('General',' ',n,n,vt,ldvt,'Right singular vectors, by row', &
ifail)
99999 Format (3X,(8F8.4))
End Program f08me_p0w_fe