# dorbdb6.f man page

dorbdb6.f

## Synopsis

### Functions/Subroutines

subroutine dorbdb6 (M1, M2, N, X1, INCX1, X2, INCX2, Q1, LDQ1, Q2, LDQ2, WORK, LWORK, INFO)
DORBDB6

## Function/Subroutine Documentation

### subroutine dorbdb6 (integer M1, integer M2, integer N, double precision, dimension(*) X1, integer INCX1, double precision, dimension(*) X2, integer INCX2, double precision, dimension(ldq1,*) Q1, integer LDQ1, double precision, dimension(ldq2,*) Q2, integer LDQ2, double precision, dimension(*) WORK, integer LWORK, integer INFO)

DORBDB6

Purpose:

``` DORBDB6 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 the zero vector is returned.```
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

NAG Ltd.

Date:

July 2012

Definition at line 156 of file dorbdb6.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

The man page dorbdb6(3) is an alias of dorbdb6.f(3).

Tue Nov 14 2017 Version 3.8.0 LAPACK