sqlt01.f - Man Page

subroutine sqlt01 (m, n, a, af, q, l, lda, tau, work, lwork, rwork, result)
SQLT01

SQLT01

Purpose:

 SQLT01 tests SGEQLF, which computes the QL factorization of an m-by-n
 matrix A, and partially tests SORGQL which forms the m-by-m
 orthogonal matrix Q.

 SQLT01 compares L 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 QL factorization of A, as returned by SGEQLF.
          See SGEQLF for further details.

Q

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

L

          L 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 SGEQLF.

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( L - 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 sqlt01.f.