TESTING/EIG/dgqrts.f(3)    Library Functions Manual    TESTING/EIG/dgqrts.f(3)

NAME
       TESTING/EIG/dgqrts.f

SYNOPSIS
   Functions/Subroutines
       subroutine dgqrts (n, m, p, a, af, q, r, lda, taua, b, bf, z, t, bwk,
           ldb, taub, work, lwork, rwork, result)
           DGQRTS

Function/Subroutine Documentation
   subroutine dgqrts (integer n, integer m, integer p, double precision,
       dimension( lda, * ) a, double precision, dimension( lda, * ) af, double
       precision, dimension( lda, * ) q, double precision, dimension( lda, * )
       r, integer lda, double precision, dimension( * ) taua, double
       precision, dimension( ldb, * ) b, double precision, dimension( ldb, * )
       bf, double precision, dimension( ldb, * ) z, double precision,
       dimension( ldb, * ) t, double precision, dimension( ldb, * ) bwk,
       integer ldb, double precision, dimension( * ) taub, double precision,
       dimension( lwork ) work, integer lwork, double precision, dimension( *
       ) rwork, double precision, dimension( 4 ) result)
       DGQRTS

       Purpose:


            DGQRTS tests DGGQRF, which computes the GQR factorization of an
            N-by-M matrix A and a N-by-P matrix B: A = Q*R and B = Q*T*Z.

       Parameters
           N

                     N is INTEGER
                     The number of rows of the matrices A and B.  N >= 0.

           M

                     M is INTEGER
                     The number of columns of the matrix A.  M >= 0.

           P

                     P is INTEGER
                     The number of columns of the matrix B.  P >= 0.

           A

                     A is DOUBLE PRECISION array, dimension (LDA,M)
                     The N-by-M matrix A.

           AF

                     AF is DOUBLE PRECISION array, dimension (LDA,N)
                     Details of the GQR factorization of A and B, as returned
                     by DGGQRF, see SGGQRF for further details.

           Q

                     Q is DOUBLE PRECISION array, dimension (LDA,N)
                     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, R and Q.
                     LDA >= max(M,N).

           TAUA

                     TAUA is DOUBLE PRECISION array, dimension (min(M,N))
                     The scalar factors of the elementary reflectors, as returned
                     by DGGQRF.

           B

                     B is DOUBLE PRECISION array, dimension (LDB,P)
                     On entry, the N-by-P matrix A.

           BF

                     BF is DOUBLE PRECISION array, dimension (LDB,N)
                     Details of the GQR factorization of A and B, as returned
                     by DGGQRF, see SGGQRF for further details.

           Z

                     Z is DOUBLE PRECISION array, dimension (LDB,P)
                     The P-by-P orthogonal matrix Z.

           T

                     T is DOUBLE PRECISION array, dimension (LDB,max(P,N))

           BWK

                     BWK is DOUBLE PRECISION array, dimension (LDB,N)

           LDB

                     LDB is INTEGER
                     The leading dimension of the arrays B, BF, Z and T.
                     LDB >= max(P,N).

           TAUB

                     TAUB is DOUBLE PRECISION array, dimension (min(P,N))
                     The scalar factors of the elementary reflectors, as returned
                     by DGGRQF.

           WORK

                     WORK is DOUBLE PRECISION array, dimension (LWORK)

           LWORK

                     LWORK is INTEGER
                     The dimension of the array WORK, LWORK >= max(N,M,P)**2.

           RWORK

                     RWORK is DOUBLE PRECISION array, dimension (max(N,M,P))

           RESULT

                     RESULT is DOUBLE PRECISION array, dimension (4)
                     The test ratios:
                       RESULT(1) = norm( R - Q'*A ) / ( MAX(M,N)*norm(A)*ULP)
                       RESULT(2) = norm( T*Z - Q'*B ) / (MAX(P,N)*norm(B)*ULP)
                       RESULT(3) = norm( I - Q'*Q ) / ( M*ULP )
                       RESULT(4) = norm( I - Z'*Z ) / ( P*ULP )

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Definition at line 174 of file dgqrts.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

LAPACK                          Version 3.12.0         TESTING/EIG/dgqrts.f(3)