cqrt023
Part of cqrt02.f(3).
Usage
Functions/Subroutines
CQRT02
Function/Subroutine Documentation
subroutine cqrt02 (integer m, integer n, integer k, complex, dimension( lda, * ) a, complex, dimension( lda, * ) af, complex, dimension( lda, * ) q, complex, dimension( lda, * ) r, integer lda, complex, dimension( * ) tau, complex, dimension( lwork ) work, integer lwork, real, dimension( * ) rwork, real, dimension( * ) result)
CQRT02
Purpose:
!> !> CQRT02 tests CUNGQR, which generates an m-by-n matrix Q with !> orthonormal columns that is defined as the product of k elementary !> reflectors. !> !> Given the QR factorization of an m-by-n matrix A, CQRT02 generates !> the orthogonal matrix Q defined by the factorization of the first k !> columns of A; it compares R(1:n,1:k) with Q(1:m,1:n)'*A(1:m,1:k), !> and checks that the columns of Q are orthonormal. !>
Parameters
M
!> M is INTEGER !> The number of rows of the matrix Q to be generated. M >= 0. !>
N
!> N is INTEGER !> The number of columns of the matrix Q to be generated. !> M >= N >= 0. !>
K
!> K is INTEGER !> The number of elementary reflectors whose product defines the !> matrix Q. N >= K >= 0. !>
A
!> A is COMPLEX array, dimension (LDA,N) !> The m-by-n matrix A which was factorized by CQRT01. !>
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,N) !>
R
!> R is COMPLEX array, dimension (LDA,N) !>
LDA
!> LDA is INTEGER !> The leading dimension of the arrays A, AF, Q and R. LDA >= M. !>
TAU
!> TAU is COMPLEX array, dimension (N) !> The scalar factors of the elementary reflectors corresponding !> to the QR factorization in AF. !>
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 133 of file cqrt02.f.