LAPACK  3.5.0
LAPACK: Linear Algebra PACKage
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drqt03.f File Reference

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Functions/Subroutines

subroutine drqt03 (M, N, K, AF, C, CC, Q, LDA, TAU, WORK, LWORK, RWORK, RESULT)
 DRQT03 More...
 

Function/Subroutine Documentation

subroutine drqt03 ( integer  M,
integer  N,
integer  K,
double precision, dimension( lda, * )  AF,
double precision, dimension( lda, * )  C,
double precision, dimension( lda, * )  CC,
double precision, dimension( lda, * )  Q,
integer  LDA,
double precision, dimension( * )  TAU,
double precision, dimension( lwork )  WORK,
integer  LWORK,
double precision, dimension( * )  RWORK,
double precision, dimension( * )  RESULT 
)

DRQT03

Purpose:
 DRQT03 tests DORMRQ, which computes Q*C, Q'*C, C*Q or C*Q'.

 DRQT03 compares the results of a call to DORMRQ with the results of
 forming Q explicitly by a call to DORGRQ and then performing matrix
 multiplication by a call to DGEMM.
Parameters
[in]M
          M is INTEGER
          The number of rows or columns of the matrix C; C is n-by-m if
          Q is applied from the left, or m-by-n if Q is applied from
          the right.  M >= 0.
[in]N
          N is INTEGER
          The order of the orthogonal matrix Q.  N >= 0.
[in]K
          K is INTEGER
          The number of elementary reflectors whose product defines the
          orthogonal matrix Q.  N >= K >= 0.
[in]AF
          AF is DOUBLE PRECISION array, dimension (LDA,N)
          Details of the RQ factorization of an m-by-n matrix, as
          returned by DGERQF. See SGERQF for further details.
[out]C
          C is DOUBLE PRECISION array, dimension (LDA,N)
[out]CC
          CC is DOUBLE PRECISION array, dimension (LDA,N)
[out]Q
          Q is DOUBLE PRECISION array, dimension (LDA,N)
[in]LDA
          LDA is INTEGER
          The leading dimension of the arrays AF, C, CC, and Q.
[in]TAU
          TAU is DOUBLE PRECISION array, dimension (min(M,N))
          The scalar factors of the elementary reflectors corresponding
          to the RQ factorization in AF.
[out]WORK
          WORK is DOUBLE PRECISION array, dimension (LWORK)
[in]LWORK
          LWORK is INTEGER
          The length of WORK.  LWORK must be at least M, and should be
          M*NB, where NB is the blocksize for this environment.
[out]RWORK
          RWORK is DOUBLE PRECISION array, dimension (M)
[out]RESULT
          RESULT is DOUBLE PRECISION array, dimension (4)
          The test ratios compare two techniques for multiplying a
          random matrix C by an n-by-n orthogonal matrix Q.
          RESULT(1) = norm( Q*C - Q*C )  / ( N * norm(C) * EPS )
          RESULT(2) = norm( C*Q - C*Q )  / ( N * norm(C) * EPS )
          RESULT(3) = norm( Q'*C - Q'*C )/ ( N * norm(C) * EPS )
          RESULT(4) = norm( C*Q' - C*Q' )/ ( N * norm(C) * EPS )
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date
November 2011

Definition at line 136 of file drqt03.f.

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