sget04.f3

Usage

Functions/Subroutines

subroutine sget04 (n, nrhs, x, ldx, xact, ldxact, rcond, resid)
SGET04

Function/Subroutine Documentation

subroutine sget04 (integer n, integer nrhs, real, dimension( ldx, * ) x, integer ldx, real, dimension( ldxact, * ) xact, integer ldxact, real rcond, real resid)

SGET04

Purpose:

!>
!> SGET04 computes the difference between a computed solution and the
!> true solution to a system of linear equations.
!>
!> RESID =  ( norm(X-XACT) * RCOND ) / ( norm(XACT) * EPS ),
!> where RCOND is the reciprocal of the condition number and EPS is the
!> machine epsilon.
!>

Parameters

!>          N is INTEGER
!>          The number of rows of the matrices X and XACT.  N >= 0.
!>

NRHS

!>          NRHS is INTEGER
!>          The number of columns of the matrices X and XACT.  NRHS >= 0.
!>

!>          X is REAL array, dimension (LDX,NRHS)
!>          The computed solution vectors.  Each vector is stored as a
!>          column of the matrix X.
!>

LDX

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

XACT

!>          XACT is REAL array, dimension( LDX, NRHS )
!>          The exact solution vectors.  Each vector is stored as a
!>          column of the matrix XACT.
!>

LDXACT

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

RCOND

!>          RCOND is REAL
!>          The reciprocal of the condition number of the coefficient
!>          matrix in the system of equations.
!>

RESID

!>          RESID is REAL
!>          The maximum over the NRHS solution vectors of
!>          ( norm(X-XACT) * RCOND ) / ( norm(XACT) * EPS )
!>

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 101 of file sget04.f.