DOKK / manpages / debian 13 / liblapack-doc / unbdb5.3.en
unbdb5(3) LAPACK unbdb5(3)

unbdb5 - {un,or}bdb5: step in uncsd2by1


subroutine cunbdb5 (m1, m2, n, x1, incx1, x2, incx2, q1, ldq1, q2, ldq2, work, lwork, info)
CUNBDB5 subroutine dorbdb5 (m1, m2, n, x1, incx1, x2, incx2, q1, ldq1, q2, ldq2, work, lwork, info)
DORBDB5 subroutine sorbdb5 (m1, m2, n, x1, incx1, x2, incx2, q1, ldq1, q2, ldq2, work, lwork, info)
SORBDB5 subroutine zunbdb5 (m1, m2, n, x1, incx1, x2, incx2, q1, ldq1, q2, ldq2, work, lwork, info)
ZUNBDB5

CUNBDB5

Purpose:


CUNBDB5 orthogonalizes the column vector
X = [ X1 ]
[ X2 ]
with respect to the columns of
Q = [ Q1 ] .
[ Q2 ]
The columns of Q must be orthonormal.
If the projection is zero according to Kahan's 'twice is enough'
criterion, then some other vector from the orthogonal complement
is returned. This vector is chosen in an arbitrary but deterministic
way.

Parameters

M1


M1 is INTEGER
The dimension of X1 and the number of rows in Q1. 0 <= M1.

M2


M2 is INTEGER
The dimension of X2 and the number of rows in Q2. 0 <= M2.

N


N is INTEGER
The number of columns in Q1 and Q2. 0 <= N.

X1


X1 is COMPLEX array, dimension (M1)
On entry, the top part of the vector to be orthogonalized.
On exit, the top part of the projected vector.

INCX1


INCX1 is INTEGER
Increment for entries of X1.

X2


X2 is COMPLEX array, dimension (M2)
On entry, the bottom part of the vector to be
orthogonalized. On exit, the bottom part of the projected
vector.

INCX2


INCX2 is INTEGER
Increment for entries of X2.

Q1


Q1 is COMPLEX array, dimension (LDQ1, N)
The top part of the orthonormal basis matrix.

LDQ1


LDQ1 is INTEGER
The leading dimension of Q1. LDQ1 >= M1.

Q2


Q2 is COMPLEX array, dimension (LDQ2, N)
The bottom part of the orthonormal basis matrix.

LDQ2


LDQ2 is INTEGER
The leading dimension of Q2. LDQ2 >= M2.

WORK


WORK is COMPLEX array, dimension (LWORK)

LWORK


LWORK is INTEGER
The dimension of the array WORK. LWORK >= N.

INFO


INFO is INTEGER
= 0: successful exit.
< 0: if INFO = -i, the i-th argument had an illegal value.

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

DORBDB5

Purpose:


DORBDB5 orthogonalizes the column vector
X = [ X1 ]
[ X2 ]
with respect to the columns of
Q = [ Q1 ] .
[ Q2 ]
The columns of Q must be orthonormal.
If the projection is zero according to Kahan's 'twice is enough'
criterion, then some other vector from the orthogonal complement
is returned. This vector is chosen in an arbitrary but deterministic
way.

Parameters

M1


M1 is INTEGER
The dimension of X1 and the number of rows in Q1. 0 <= M1.

M2


M2 is INTEGER
The dimension of X2 and the number of rows in Q2. 0 <= M2.

N


N is INTEGER
The number of columns in Q1 and Q2. 0 <= N.

X1


X1 is DOUBLE PRECISION array, dimension (M1)
On entry, the top part of the vector to be orthogonalized.
On exit, the top part of the projected vector.

INCX1


INCX1 is INTEGER
Increment for entries of X1.

X2


X2 is DOUBLE PRECISION array, dimension (M2)
On entry, the bottom part of the vector to be
orthogonalized. On exit, the bottom part of the projected
vector.

INCX2


INCX2 is INTEGER
Increment for entries of X2.

Q1


Q1 is DOUBLE PRECISION array, dimension (LDQ1, N)
The top part of the orthonormal basis matrix.

LDQ1


LDQ1 is INTEGER
The leading dimension of Q1. LDQ1 >= M1.

Q2


Q2 is DOUBLE PRECISION array, dimension (LDQ2, N)
The bottom part of the orthonormal basis matrix.

LDQ2


LDQ2 is INTEGER
The leading dimension of Q2. LDQ2 >= M2.

WORK


WORK is DOUBLE PRECISION array, dimension (LWORK)

LWORK


LWORK is INTEGER
The dimension of the array WORK. LWORK >= N.

INFO


INFO is INTEGER
= 0: successful exit.
< 0: if INFO = -i, the i-th argument had an illegal value.

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

SORBDB5

Purpose:


SORBDB5 orthogonalizes the column vector
X = [ X1 ]
[ X2 ]
with respect to the columns of
Q = [ Q1 ] .
[ Q2 ]
The columns of Q must be orthonormal.
If the projection is zero according to Kahan's 'twice is enough'
criterion, then some other vector from the orthogonal complement
is returned. This vector is chosen in an arbitrary but deterministic
way.

Parameters

M1


M1 is INTEGER
The dimension of X1 and the number of rows in Q1. 0 <= M1.

M2


M2 is INTEGER
The dimension of X2 and the number of rows in Q2. 0 <= M2.

N


N is INTEGER
The number of columns in Q1 and Q2. 0 <= N.

X1


X1 is REAL array, dimension (M1)
On entry, the top part of the vector to be orthogonalized.
On exit, the top part of the projected vector.

INCX1


INCX1 is INTEGER
Increment for entries of X1.

X2


X2 is REAL array, dimension (M2)
On entry, the bottom part of the vector to be
orthogonalized. On exit, the bottom part of the projected
vector.

INCX2


INCX2 is INTEGER
Increment for entries of X2.

Q1


Q1 is REAL array, dimension (LDQ1, N)
The top part of the orthonormal basis matrix.

LDQ1


LDQ1 is INTEGER
The leading dimension of Q1. LDQ1 >= M1.

Q2


Q2 is REAL array, dimension (LDQ2, N)
The bottom part of the orthonormal basis matrix.

LDQ2


LDQ2 is INTEGER
The leading dimension of Q2. LDQ2 >= M2.

WORK


WORK is REAL array, dimension (LWORK)

LWORK


LWORK is INTEGER
The dimension of the array WORK. LWORK >= N.

INFO


INFO is INTEGER
= 0: successful exit.
< 0: if INFO = -i, the i-th argument had an illegal value.

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

ZUNBDB5

Purpose:


ZUNBDB5 orthogonalizes the column vector
X = [ X1 ]
[ X2 ]
with respect to the columns of
Q = [ Q1 ] .
[ Q2 ]
The columns of Q must be orthonormal.
If the projection is zero according to Kahan's 'twice is enough'
criterion, then some other vector from the orthogonal complement
is returned. This vector is chosen in an arbitrary but deterministic
way.

Parameters

M1


M1 is INTEGER
The dimension of X1 and the number of rows in Q1. 0 <= M1.

M2


M2 is INTEGER
The dimension of X2 and the number of rows in Q2. 0 <= M2.

N


N is INTEGER
The number of columns in Q1 and Q2. 0 <= N.

X1


X1 is COMPLEX*16 array, dimension (M1)
On entry, the top part of the vector to be orthogonalized.
On exit, the top part of the projected vector.

INCX1


INCX1 is INTEGER
Increment for entries of X1.

X2


X2 is COMPLEX*16 array, dimension (M2)
On entry, the bottom part of the vector to be
orthogonalized. On exit, the bottom part of the projected
vector.

INCX2


INCX2 is INTEGER
Increment for entries of X2.

Q1


Q1 is COMPLEX*16 array, dimension (LDQ1, N)
The top part of the orthonormal basis matrix.

LDQ1


LDQ1 is INTEGER
The leading dimension of Q1. LDQ1 >= M1.

Q2


Q2 is COMPLEX*16 array, dimension (LDQ2, N)
The bottom part of the orthonormal basis matrix.

LDQ2


LDQ2 is INTEGER
The leading dimension of Q2. LDQ2 >= M2.

WORK


WORK is COMPLEX*16 array, dimension (LWORK)

LWORK


LWORK is INTEGER
The dimension of the array WORK. LWORK >= N.

INFO


INFO is INTEGER
= 0: successful exit.
< 0: if INFO = -i, the i-th argument had an illegal value.

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

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