TESTING/LIN/spbt02.f(3)

NAME
TESTING/LIN/spbt02.f

SYNOPSIS

  Functions/Subroutines
subroutine spbt02 (uplo, n, kd, nrhs, a, lda, x, ldx, b, ldb, rwork, resid)
SPBT02

Function/Subroutine Documentation

  subroutine spbt02 (character uplo, integer n, integer kd, integer nrhs, real, dimension( lda, * ) a, integer lda, real, dimension( ldx, * ) x, integer ldx, real, dimension( ldb, * ) b, integer ldb, real, dimension( * ) rwork, real resid)

SPBT02

Purpose:

    !>
    !> SPBT02 computes the residual for a solution of a symmetric banded
    !> system of equations  A*x = b:
    !>    RESID = norm( B - A*X ) / ( norm(A) * norm(X) * EPS)
    !> where EPS is the machine precision.
    !>

Parameters
    UPLO

    !>          UPLO is CHARACTER*1
    !>          Specifies whether the upper or lower triangular part of the
    !>          symmetric matrix A is stored:
    !>          = 'U':  Upper triangular
    !>          = 'L':  Lower triangular
    !>

    N

    !>          N is INTEGER
    !>          The number of rows and columns of the matrix A.  N >= 0.
    !>

    KD

    !>          KD is INTEGER
    !>          The number of super-diagonals of the matrix A if UPLO = 'U',
    !>          or the number of sub-diagonals if UPLO = 'L'.  KD >= 0.
    !>

    NRHS

    !>          NRHS is INTEGER
    !>          The number of right hand sides. NRHS >= 0.
    !>

    A

    !>          A is REAL array, dimension (LDA,N)
    !>          The original symmetric band matrix A.  If UPLO = 'U', the
    !>          upper triangular part of A is stored as a band matrix; if
    !>          UPLO = 'L', the lower triangular part of A is stored.  The
    !>          columns of the appropriate triangle are stored in the columns
    !>          of A and the diagonals of the triangle are stored in the rows
    !>          of A.  See SPBTRF for further details.
    !>

    LDA

    !>          LDA is INTEGER.
    !>          The leading dimension of the array A.  LDA >= max(1,KD+1).
    !>

    X

    !>          X is REAL array, dimension (LDX,NRHS)
    !>          The computed solution vectors for the system of linear
    !>          equations.
    !>

    LDX

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

    B

    !>          B is REAL array, dimension (LDB,NRHS)
    !>          On entry, the right hand side vectors for the system of
    !>          linear equations.
    !>          On exit, B is overwritten with the difference B - A*X.
    !>

    LDB

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

    RWORK

    !>          RWORK is REAL array, dimension (N)
    !>

    RESID

    !>          RESID is REAL
    !>          The maximum over the number of right hand sides of
    !>          norm(B - A*X) / ( norm(A) * norm(X) * EPS ).
    !>

Author
    Univ. of Tennessee

    Univ. of California Berkeley

    Univ. of Colorado Denver

    NAG Ltd.

Definition at line 134 of file spbt02.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.