public interface ormbr
If VECT = 'Q', ORMBR: overwrites the general real M-by-N matrix C
with
SIDE = 'L' SIDE = 'R'
TRANS = 'N': Q * C C * Q
TRANS = 'T': QT * C C * QT
If VECT = 'P', ORMBR overwrites the general real M-by-N matrix C
with
SIDE = 'L' SIDE = 'R'
TRANS = 'N': P * C C * P
TRANS = 'T': PT * C C * PT
Here Q and PT are the orthogonal matrices determined by DGEBRD when
reducing a real matrix A to bidiagonal form: A = Q * B * PT. Q and
PT are defined as products of elementary reflectors H(i) and G(i)
respectively.
Let nq = m if SIDE = 'L' and nq = n if SIDE = 'R'. Thus nq is the
order of the orthogonal matrix Q or PT that is applied.
If VECT = 'Q', A is assumed to have been an NQ-by-K matrix:
if nq >= k, Q = H(1) H(2) . . . H(k);
if nq < k, Q = H(1) H(2) . . . H(nq-1).
If VECT = 'P', A is assumed to have been a K-by-NQ matrix:
if k < nq, P = G(1) G(2) . . . G(k);
if k >= nq, P = G(1) G(2) . . . G(nq-1).
Subroutines
Arguments
| Type |
Intent | Optional | Attributes |
|
Name |
|
|
character(len=1),
|
intent(in) |
|
|
:: |
vect |
|
|
character(len=1),
|
intent(in) |
|
|
:: |
side |
|
|
character(len=1),
|
intent(in) |
|
|
:: |
trans |
|
|
integer(kind=ilp),
|
intent(in) |
|
|
:: |
m |
|
|
integer(kind=ilp),
|
intent(in) |
|
|
:: |
n |
|
|
integer(kind=ilp),
|
intent(in) |
|
|
:: |
k |
|
|
real(kind=dp),
|
intent(inout) |
|
|
:: |
a(lda,*) |
|
|
integer(kind=ilp),
|
intent(in) |
|
|
:: |
lda |
|
|
real(kind=dp),
|
intent(in) |
|
|
:: |
tau(*) |
|
|
real(kind=dp),
|
intent(inout) |
|
|
:: |
c(ldc,*) |
|
|
integer(kind=ilp),
|
intent(in) |
|
|
:: |
ldc |
|
|
real(kind=dp),
|
intent(out) |
|
|
:: |
work(*) |
|
|
integer(kind=ilp),
|
intent(in) |
|
|
:: |
lwork |
|
|
integer(kind=ilp),
|
intent(out) |
|
|
:: |
info |
|
Arguments
| Type |
Intent | Optional | Attributes |
|
Name |
|
|
character(len=1),
|
intent(in) |
|
|
:: |
vect |
|
|
character(len=1),
|
intent(in) |
|
|
:: |
side |
|
|
character(len=1),
|
intent(in) |
|
|
:: |
trans |
|
|
integer(kind=ilp),
|
intent(in) |
|
|
:: |
m |
|
|
integer(kind=ilp),
|
intent(in) |
|
|
:: |
n |
|
|
integer(kind=ilp),
|
intent(in) |
|
|
:: |
k |
|
|
real(kind=sp),
|
intent(inout) |
|
|
:: |
a(lda,*) |
|
|
integer(kind=ilp),
|
intent(in) |
|
|
:: |
lda |
|
|
real(kind=sp),
|
intent(in) |
|
|
:: |
tau(*) |
|
|
real(kind=sp),
|
intent(inout) |
|
|
:: |
c(ldc,*) |
|
|
integer(kind=ilp),
|
intent(in) |
|
|
:: |
ldc |
|
|
real(kind=sp),
|
intent(out) |
|
|
:: |
work(*) |
|
|
integer(kind=ilp),
|
intent(in) |
|
|
:: |
lwork |
|
|
integer(kind=ilp),
|
intent(out) |
|
|
:: |
info |
|
Module Procedures