dgeqrs.f - Man Page

SRC/DEPRECATED/dgeqrs.f

Synopsis

Functions/Subroutines

subroutine dgeqrs (m, n, nrhs, a, lda, tau, b, ldb, work, lwork, info)
DGEQRS

Function/Subroutine Documentation

subroutine dgeqrs (integer m, integer n, integer nrhs, double precision, dimension( lda, * ) a, integer lda, double precision, dimension( * ) tau, double precision, dimension( ldb, * ) b, integer ldb, double precision, dimension( lwork ) work, integer lwork, integer info)

DGEQRS

Purpose:

 Solve the least squares problem
     min || A*X - B ||
 using the QR factorization
     A = Q*R
 computed by DGEQRF.
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 DOUBLE PRECISION array, dimension (LDA,N)
          Details of the QR factorization of the original matrix A as
          returned by DGEQRF.

LDA

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

TAU

          TAU is DOUBLE PRECISION array, dimension (N)
          Details of the orthogonal matrix Q.

B

          B is DOUBLE PRECISION 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 DOUBLE PRECISION 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 119 of file dgeqrs.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

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

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