# zgerqs.f - Man Page

TESTING/LIN/zgerqs.f

## Synopsis

### Functions/Subroutines

subroutine zgerqs (m, n, nrhs, a, lda, tau, b, ldb, work, lwork, info)
ZGERQS

## Function/Subroutine Documentation

### subroutine zgerqs (integer m, integer n, integer nrhs, complex*16, dimension( lda, * ) a, integer lda, complex*16, dimension( * ) tau, complex*16, dimension( ldb, * ) b, integer ldb, complex*16, dimension( lwork ) work, integer lwork, integer info)

ZGERQS

Purpose:

``` Compute a minimum-norm solution
min || A*X - B ||
using the RQ factorization
A = R*Q
computed by ZGERQF.```
Parameters

M

```          M is INTEGER
The number of rows of the matrix A.  M >= 0.```

N

```          N is INTEGER
The number of columns of the matrix A.  N >= M >= 0.```

NRHS

```          NRHS is INTEGER
The number of columns of B.  NRHS >= 0.```

A

```          A is COMPLEX*16 array, dimension (LDA,N)
Details of the RQ factorization of the original matrix A as
returned by ZGERQF.```

LDA

```          LDA is INTEGER
The leading dimension of the array A.  LDA >= M.```

TAU

```          TAU is COMPLEX*16 array, dimension (M)
Details of the orthogonal matrix Q.```

B

```          B is COMPLEX*16 array, dimension (LDB,NRHS)
On entry, the right hand side vectors for the linear system.
On exit, the solution vectors X.  Each solution vector
is contained in rows 1:N of a column of B.```

LDB

```          LDB is INTEGER
The leading dimension of the array B. LDB >= max(1,N).```

WORK

`          WORK is COMPLEX*16 array, dimension (LWORK)`

LWORK

```          LWORK is INTEGER
The length of the array WORK.  LWORK must be at least NRHS,
and should be at least NRHS*NB, where NB is the block size
for this environment.```

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.

Definition at line 120 of file zgerqs.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

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

Tue Nov 28 2023 12:08:43 Version 3.12.0 LAPACK