drzt01.f3

Usage

Functions/Subroutines

double precision function drzt01 (m, n, a, af, lda, tau, work, lwork)
DRZT01

Function/Subroutine Documentation

double precision function drzt01 (integer m, integer n, double precision, dimension( lda, * ) a, double precision, dimension( lda, * ) af, integer lda, double precision, dimension( * ) tau, double precision, dimension( lwork ) work, integer lwork)

DRZT01

Purpose:

!>
!> DRZT01 returns
!>      || A - R*Q || / ( M * eps * ||A|| )
!> for an upper trapezoidal A that was factored with DTZRZF.
!>

Parameters

!>          M is INTEGER
!>          The number of rows of the matrices A and AF.
!>

!>          N is INTEGER
!>          The number of columns of the matrices A and AF.
!>

!>          A is DOUBLE PRECISION array, dimension (LDA,N)
!>          The original upper trapezoidal M by N matrix A.
!>

!>          AF is DOUBLE PRECISION array, dimension (LDA,N)
!>          The output of DTZRZF for input matrix A.
!>          The lower triangle is not referenced.
!>

LDA

!>          LDA is INTEGER
!>          The leading dimension of the arrays A and AF.
!>

TAU

!>          TAU is DOUBLE PRECISION array, dimension (M)
!>          Details of the Householder transformations as returned by
!>          DTZRZF.
!>

WORK

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

LWORK

!>          LWORK is INTEGER
!>          The length of the array WORK.  LWORK >= m*n + m*nb.
!>

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 96 of file drzt01.f.