# cgeqls.f - Man Page

TESTING/LIN/cgeqls.f

## Synopsis

### Functions/Subroutines

subroutine cgeqls (m, n, nrhs, a, lda, tau, b, ldb, work, lwork, info)
CGEQLS

## Function/Subroutine Documentation

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

CGEQLS

Purpose:

``` Solve the least squares problem
min || A*X - B ||
using the QL factorization
A = Q*L
computed by CGEQLF.```
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.  M >= N >= 0.```

NRHS

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

A

```          A is COMPLEX array, dimension (LDA,N)
Details of the QL factorization of the original matrix A as
returned by CGEQLF.```

LDA

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

TAU

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

B

```          B is COMPLEX array, dimension (LDB,NRHS)
On entry, the m-by-nrhs right hand side matrix B.
On exit, the n-by-nrhs solution matrix X, stored in rows
m-n+1:m.```

LDB

```          LDB is INTEGER
The leading dimension of the array B. LDB >= M.```

WORK

`          WORK is COMPLEX 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 cgeqls.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

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

Tue Nov 28 2023 12:08:42 Version 3.12.0 LAPACK