Scroll to navigation

/home/abuild/rpmbuild/BUILD/lapack-3.12.0/TESTING/LIN/dgtt01.f(3) Library Functions Manual /home/abuild/rpmbuild/BUILD/lapack-3.12.0/TESTING/LIN/dgtt01.f(3)

NAME

/home/abuild/rpmbuild/BUILD/lapack-3.12.0/TESTING/LIN/dgtt01.f

SYNOPSIS

Functions/Subroutines


subroutine DGTT01 (n, dl, d, du, dlf, df, duf, du2, ipiv, work, ldwork, rwork, resid)
DGTT01

Function/Subroutine Documentation

subroutine DGTT01 (integer n, double precision, dimension( * ) dl, double precision, dimension( * ) d, double precision, dimension( * ) du, double precision, dimension( * ) dlf, double precision, dimension( * ) df, double precision, dimension( * ) duf, double precision, dimension( * ) du2, integer, dimension( * ) ipiv, double precision, dimension( ldwork, * ) work, integer ldwork, double precision, dimension( * ) rwork, double precision resid)

DGTT01

Purpose:

!>
!> DGTT01 reconstructs a tridiagonal matrix A from its LU factorization
!> and computes the residual
!>    norm(L*U - A) / ( norm(A) * EPS ),
!> where EPS is the machine epsilon.
!> 

Parameters

N

!>          N is INTEGER
!>          The order of the matrix A.  N >= 0.
!> 

DL

!>          DL is DOUBLE PRECISION array, dimension (N-1)
!>          The (n-1) sub-diagonal elements of A.
!> 

D

!>          D is DOUBLE PRECISION array, dimension (N)
!>          The diagonal elements of A.
!> 

DU

!>          DU is DOUBLE PRECISION array, dimension (N-1)
!>          The (n-1) super-diagonal elements of A.
!> 

DLF

!>          DLF is DOUBLE PRECISION array, dimension (N-1)
!>          The (n-1) multipliers that define the matrix L from the
!>          LU factorization of A.
!> 

DF

!>          DF is DOUBLE PRECISION array, dimension (N)
!>          The n diagonal elements of the upper triangular matrix U from
!>          the LU factorization of A.
!> 

DUF

!>          DUF is DOUBLE PRECISION array, dimension (N-1)
!>          The (n-1) elements of the first super-diagonal of U.
!> 

DU2

!>          DU2 is DOUBLE PRECISION array, dimension (N-2)
!>          The (n-2) elements of the second super-diagonal of U.
!> 

IPIV

!>          IPIV is INTEGER array, dimension (N)
!>          The pivot indices; for 1 <= i <= n, row i of the matrix was
!>          interchanged with row IPIV(i).  IPIV(i) will always be either
!>          i or i+1; IPIV(i) = i indicates a row interchange was not
!>          required.
!> 

WORK

!>          WORK is DOUBLE PRECISION array, dimension (LDWORK,N)
!> 

LDWORK

!>          LDWORK is INTEGER
!>          The leading dimension of the array WORK.  LDWORK >= max(1,N).
!> 

RWORK

!>          RWORK is DOUBLE PRECISION array, dimension (N)
!> 

RESID

!>          RESID is DOUBLE PRECISION
!>          The scaled residual:  norm(L*U - A) / (norm(A) * EPS)
!> 

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 132 of file dgtt01.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Version 3.12.0 LAPACK