cqpt013
Part of cqpt01.f(3).
Usage
Functions/Subroutines
CQPT01
Function/Subroutine Documentation
real function cqpt01 (integer m, integer n, integer k, complex, dimension( lda, * ) a, complex, dimension( lda, * ) af, integer lda, complex, dimension( * ) tau, integer, dimension( * ) jpvt, complex, dimension( lwork ) work, integer lwork)
CQPT01
Purpose:
!> !> CQPT01 tests the QR-factorization with pivoting of a matrix A. The !> array AF contains the (possibly partial) QR-factorization of A, where !> the upper triangle of AF(1:k,1:k) is a partial triangular factor, !> the entries below the diagonal in the first k columns are the !> Householder vectors, and the rest of AF contains a partially updated !> matrix. !> !> This function returns ||A*P - Q*R|| / ( ||norm(A)||*eps*max(M,N) ) !> where || . || is matrix one norm. !>
Parameters
M
!> M is INTEGER !> The number of rows of the matrices A and AF. !>
N
!> N is INTEGER !> The number of columns of the matrices A and AF. !>
K
!> K is INTEGER !> The number of columns of AF that have been reduced !> to upper triangular form. !>
A
!> A is COMPLEX array, dimension (LDA, N) !> The original matrix A. !>
AF
!> AF is COMPLEX array, dimension (LDA,N) !> The (possibly partial) output of CGEQPF. The upper triangle !> of AF(1:k,1:k) is a partial triangular factor, the entries !> below the diagonal in the first k columns are the Householder !> vectors, and the rest of AF contains a partially updated !> matrix. !>
LDA
!> LDA is INTEGER !> The leading dimension of the arrays A and AF. !>
TAU
!> TAU is COMPLEX array, dimension (K) !> Details of the Householder transformations as returned by !> CGEQPF. !>
JPVT
!> JPVT is INTEGER array, dimension (N) !> Pivot information as returned by CGEQPF. !>
WORK
!> WORK is COMPLEX array, dimension (LWORK) !>
LWORK
!> LWORK is INTEGER !> The length of the array WORK. LWORK >= M*N+N. !>
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 119 of file cqpt01.f.