cqrt01.f - Man Page

subroutine cqrt01 (m, n, a, af, q, r, lda, tau, work, lwork, rwork, result)
CQRT01

CQRT01

Purpose:

 CQRT01 tests CGEQRF, which computes the QR factorization of an m-by-n
 matrix A, and partially tests CUNGQR which forms the m-by-m
 orthogonal matrix Q.

 CQRT01 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 COMPLEX array, dimension (LDA,N)
          The m-by-n matrix A.

AF

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

Q

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

R

          R is COMPLEX 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 COMPLEX array, dimension (min(M,N))
          The scalar factors of the elementary reflectors, as returned
          by CGEQRF.

WORK

          WORK is COMPLEX 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 cqrt01.f.