dqrt01.f3

!>
!> DQRT01 tests DGEQRF, which computes the QR factorization of an m-by-n
!> matrix A, and partially tests DORGQR which forms the m-by-m
!> orthogonal matrix Q.
!>
!> DQRT01 compares R with Q'*A, and checks that Q is orthogonal.
!> 

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 DOUBLE PRECISION array, dimension (LDA,N)
!>          The m-by-n matrix A.
!> 

AF

!>          AF is DOUBLE PRECISION array, dimension (LDA,N)
!>          Details of the QR factorization of A, as returned by DGEQRF.
!>          See DGEQRF for further details.
!> 

Q

!>          Q is DOUBLE PRECISION array, dimension (LDA,M)
!>          The m-by-m orthogonal matrix Q.
!> 

R

!>          R is DOUBLE PRECISION 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 DOUBLE PRECISION array, dimension (min(M,N))
!>          The scalar factors of the elementary reflectors, as returned
!>          by DGEQRF.
!> 

WORK

!>          WORK is DOUBLE PRECISION array, dimension (LWORK)
!> 

LWORK

!>          LWORK is INTEGER
!>          The dimension of the array WORK.
!> 

RWORK

!>          RWORK is DOUBLE PRECISION array, dimension (M)
!> 

RESULT

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

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