sqrt01p.f - Man Page

TESTING/LIN/sqrt01p.f

Synopsis

Functions/Subroutines

subroutine sqrt01p (m, n, a, af, q, r, lda, tau, work, lwork, rwork, result)
SQRT01P

Function/Subroutine Documentation

subroutine sqrt01p (integer m, integer n, real, dimension( lda, * ) a, real, dimension( lda, * ) af, real, dimension( lda, * ) q, real, dimension( lda, * ) r, integer lda, real, dimension( * ) tau, real, dimension( lwork ) work, integer lwork, real, dimension( * ) rwork, real, dimension( * ) result)

SQRT01P

Purpose:

 SQRT01P tests SGEQRFP, which computes the QR factorization of an m-by-n
 matrix A, and partially tests SORGQR which forms the m-by-m
 orthogonal matrix Q.

 SQRT01P compares R with Q'*A, and checks that Q is orthogonal.
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 >= 0.

A

          A is REAL array, dimension (LDA,N)
          The m-by-n matrix A.

AF

          AF is REAL array, dimension (LDA,N)
          Details of the QR factorization of A, as returned by SGEQRFP.
          See SGEQRFP for further details.

Q

          Q is REAL array, dimension (LDA,M)
          The m-by-m orthogonal matrix Q.

R

          R is REAL array, dimension (LDA,max(M,N))

LDA

          LDA is INTEGER
          The leading dimension of the arrays A, AF, Q and R.
          LDA >= max(M,N).

TAU

          TAU is REAL array, dimension (min(M,N))
          The scalar factors of the elementary reflectors, as returned
          by SGEQRFP.

WORK

          WORK is REAL array, dimension (LWORK)

LWORK

          LWORK is INTEGER
          The dimension of the array WORK.

RWORK

          RWORK is REAL array, dimension (M)

RESULT

          RESULT is REAL array, dimension (2)
          The test ratios:
          RESULT(1) = norm( R - Q'*A ) / ( M * norm(A) * EPS )
          RESULT(2) = norm( I - Q'*Q ) / ( M * EPS )
Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 124 of file sqrt01p.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

The man page sqrt01p(3) is an alias of sqrt01p.f(3).

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