orgtsqr_row Interface

public interface orgtsqr_row

ORGTSQR_ROW generates an M-by-N real matrix Q_out with orthonormal columns from the output of DLATSQR. These N orthonormal columns are the first N columns of a product of complex unitary matrices Q(k)_in of order M, which are returned by DLATSQR in a special format. Q_out = first_N_columns_of( Q(1)_in * Q(2)_in * ... * Q(k)_in ). The input matrices Q(k)_in are stored in row and column blocks in A. See the documentation of DLATSQR for more details on the format of Q(k)_in, where each Q(k)_in is represented by block Householder transformations. This routine calls an auxiliary routine DLARFB_GETT, where the computation is performed on each individual block. The algorithm first sweeps NB-sized column blocks from the right to left starting in the bottom row block and continues to the top row block (hence _ROW in the routine name). This sweep is in reverse order of the order in which DLATSQR generates the output blocks.


Subroutines

public pure subroutine dorgtsqr_row(m, n, mb, nb, a, lda, t, ldt, work, lwork, info)

Arguments

Type IntentOptional Attributes Name
integer(kind=ilp), intent(in) :: m
integer(kind=ilp), intent(in) :: n
integer(kind=ilp), intent(in) :: mb
integer(kind=ilp), intent(in) :: nb
real(kind=dp), intent(inout) :: a(lda,*)
integer(kind=ilp), intent(in) :: lda
real(kind=dp), intent(in) :: t(ldt,*)
integer(kind=ilp), intent(in) :: ldt
real(kind=dp), intent(out) :: work(*)
integer(kind=ilp), intent(in) :: lwork
integer(kind=ilp), intent(out) :: info

public pure subroutine sorgtsqr_row(m, n, mb, nb, a, lda, t, ldt, work, lwork, info)

Arguments

Type IntentOptional Attributes Name
integer(kind=ilp), intent(in) :: m
integer(kind=ilp), intent(in) :: n
integer(kind=ilp), intent(in) :: mb
integer(kind=ilp), intent(in) :: nb
real(kind=sp), intent(inout) :: a(lda,*)
integer(kind=ilp), intent(in) :: lda
real(kind=sp), intent(in) :: t(ldt,*)
integer(kind=ilp), intent(in) :: ldt
real(kind=sp), intent(out) :: work(*)
integer(kind=ilp), intent(in) :: lwork
integer(kind=ilp), intent(out) :: info

Module Procedures

public interface stdlib_dorgtsqr_row()

Arguments

None

public interface stdlib_sorgtsqr_row()

Arguments

None