cgeqrs.f - Man Page

SRC/DEPRECATED/cgeqrs.f

Synopsis

Functions/Subroutines

subroutine cgeqrs (m, n, nrhs, a, lda, tau, b, ldb, work, lwork, info)
CGEQRS

Function/Subroutine Documentation

subroutine cgeqrs (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)

CGEQRS

Purpose:

``` Solve the least squares problem
min || A*X - B ||
using the QR factorization
A = Q*R
computed by CGEQRF.```
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 QR factorization of the original matrix A as
returned by CGEQRF.```

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.```

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 119 of file cgeqrs.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

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

Tue Nov 28 2023 12:08:41 Version 3.12.0 LAPACK