# cgerqs.f - Man Page

TESTING/LIN/cgerqs.f

## Synopsis

### Functions/Subroutines

subroutine **cgerqs** (m, n, nrhs, a, lda, tau, b, ldb, work, lwork, info)**CGERQS**

## Function/Subroutine Documentation

### subroutine cgerqs (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)

**CGERQS**

**Purpose:**

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

**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 array, dimension (LDA,N) Details of the RQ factorization of the original matrix A as returned by CGERQF.

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

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

*B*B is COMPLEX 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 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

Univ. of Colorado Denver

NAG Ltd.

Definition at line **120** of file **cgerqs.f**.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

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

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