fortran-lapack
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la_lapack::ungbr Interface Reference

UNGBR: generates one of the complex unitary matrices Q or P**H determined by CGEBRD when reducing a complex matrix A to bidiagonal form: A = Q * B * P**H. Q and P**H are defined as products of elementary reflectors H(i) or G(i) respectively. If VECT = 'Q', A is assumed to have been an M-by-K matrix, and Q is of order M: if m >= k, Q = H(1) H(2) . . . H(k) and UNGBR returns the first n columns of Q, where m >= n >= k; if m < k, Q = H(1) H(2) . . . H(m-1) and UNGBR returns Q as an M-by-M matrix. If VECT = 'P', A is assumed to have been a K-by-N matrix, and P**H is of order N: if k < n, P**H = G(k) . . . G(2) G(1) and UNGBR returns the first m rows of P**H, where n >= m >= k; if k >= n, P**H = G(n-1) . . . G(2) G(1) and UNGBR returns P**H as an N-by-N matrix. More...

Public Member Functions

pure subroutine cungbr (vect, m, n, k, a, lda, tau, work, lwork, info)
 
 la_cungbr
 
 la_wungbr
 
pure subroutine zungbr (vect, m, n, k, a, lda, tau, work, lwork, info)
 
 la_zungbr
 

Detailed Description

UNGBR: generates one of the complex unitary matrices Q or P**H determined by CGEBRD when reducing a complex matrix A to bidiagonal form: A = Q * B * P**H. Q and P**H are defined as products of elementary reflectors H(i) or G(i) respectively. If VECT = 'Q', A is assumed to have been an M-by-K matrix, and Q is of order M: if m >= k, Q = H(1) H(2) . . . H(k) and UNGBR returns the first n columns of Q, where m >= n >= k; if m < k, Q = H(1) H(2) . . . H(m-1) and UNGBR returns Q as an M-by-M matrix. If VECT = 'P', A is assumed to have been a K-by-N matrix, and P**H is of order N: if k < n, P**H = G(k) . . . G(2) G(1) and UNGBR returns the first m rows of P**H, where n >= m >= k; if k >= n, P**H = G(n-1) . . . G(2) G(1) and UNGBR returns P**H as an N-by-N matrix.

Member Function/Subroutine Documentation

◆ cungbr()

pure subroutine la_lapack::ungbr::cungbr ( character, intent(in)  vect,
integer(ilp), intent(in)  m,
integer(ilp), intent(in)  n,
integer(ilp), intent(in)  k,
complex(sp), dimension(lda,*), intent(inout)  a,
integer(ilp), intent(in)  lda,
complex(sp), dimension(*), intent(in)  tau,
complex(sp), dimension(*), intent(out)  work,
integer(ilp), intent(in)  lwork,
integer(ilp), intent(out)  info 
)

◆ la_cungbr()

la_lapack::ungbr::la_cungbr

◆ la_wungbr()

la_lapack::ungbr::la_wungbr

◆ la_zungbr()

la_lapack::ungbr::la_zungbr

◆ zungbr()

pure subroutine la_lapack::ungbr::zungbr ( character, intent(in)  vect,
integer(ilp), intent(in)  m,
integer(ilp), intent(in)  n,
integer(ilp), intent(in)  k,
complex(dp), dimension(lda,*), intent(inout)  a,
integer(ilp), intent(in)  lda,
complex(dp), dimension(*), intent(in)  tau,
complex(dp), dimension(*), intent(out)  work,
integer(ilp), intent(in)  lwork,
integer(ilp), intent(out)  info 
)

The documentation for this interface was generated from the following file: