Program f08kp_p0w_fe
! F08KP_P0W_F Example Program Text
! Mark 27.2 Release. NAG Copyright 2021.
! .. Use Statements ..
Use iso_c_binding, Only: c_ptr
Use nagad_library, Only: f08kp_p0w_f
Use nag_library, Only: nag_wp, x04daf
! .. Implicit None Statement ..
Implicit None
! .. Parameters ..
Integer, Parameter :: nb = 64, nin = 5, nout = 6
! .. Local Scalars ..
Type (c_ptr) :: ad_handle
Integer :: i, ifail, lda, ldu, ldvt, lwork, m, &
n
! .. Local Arrays ..
Complex (Kind=nag_wp), Allocatable :: a(:,:), u(:,:), vt(:,:), work(:)
Complex (Kind=nag_wp) :: dummy(1)
Real (Kind=nag_wp), Allocatable :: rwork(:), s(:)
! .. Intrinsic Procedures ..
Intrinsic :: max, nint, real
! .. Executable Statements ..
Write (nout,*) 'F08KP_P0W_F Example Program Results'
! Skip heading in data file
Read (nin,*)
Read (nin,*) m, n
lda = m
ldu = m
ldvt = n
Allocate (a(lda,n),s(m),u(ldu,m),vt(ldvt,n),rwork(5*n))
! Use routine workspace query to get optimal workspace.
lwork = -1
ifail = 0
Call f08kp_p0w_f(ad_handle,'A','A',m,n,a,lda,s,u,ldu,vt,ldvt,dummy, &
lwork,rwork,ifail)
! Make sure that there is enough workspace for block size nb.
lwork = max(m+3*n+nb*(m+n),nint(real(dummy(1))))
Allocate (work(lwork))
! Read the m by n matrix A from data file
Read (nin,*)(a(i,1:n),i=1,m)
! Compute the singular values and left and right singular vectors
! of A (A = U*S*(V**T), m.le.n)
ifail = 0
Call f08kp_p0w_f(ad_handle,'A','A',m,n,a,lda,s,u,ldu,vt,ldvt,work,lwork, &
rwork,ifail)
! Print solution
Write (nout,*)
Write (nout,*) 'Singular values'
Write (nout,99999) s(1:n)
99999 Format (3X,(8F8.4))
Flush (nout)
ifail = 0
Call x04daf('General',' ',m,m,u,ldu,'Left singular vectors',ifail)
Write (nout,*)
Flush (nout)
Call x04daf('General',' ',n,n,vt,ldvt,'Right singular vectors by row', &
ifail)
End Program f08kp_p0w_fe