TESTING/LIN/dgbt02.f(3)

NAME
TESTING/LIN/dgbt02.f

SYNOPSIS

  Functions/Subroutines
subroutine dgbt02 (trans, m, n, kl, ku, nrhs, a, lda, x, ldx, b, ldb, rwork, resid)
DGBT02

Function/Subroutine Documentation

  subroutine dgbt02 (character trans, integer m, integer n, integer kl, integer ku, integer nrhs, double precision, dimension( lda, * ) a, integer lda, double precision, dimension( ldx, * ) x, integer ldx, double precision, dimension( ldb, * ) b, integer ldb, double precision, dimension( * ) rwork, double precision resid)

DGBT02

Purpose:

     DGBT02 computes the residual for a solution of a banded system of
     equations op(A)*X = B:
        RESID = norm(B - op(A)*X) / ( norm(op(A)) * norm(X) * EPS ),
     where op(A) = A or A**T, depending on TRANS, and EPS is the
     machine epsilon.
     The norm used is the 1-norm.

Parameters
    TRANS

              TRANS is CHARACTER*1
              Specifies the form of the system of equations:
              = 'N':  A    * X = B  (No transpose)
              = 'T':  A**T * X = B  (Transpose)
              = 'C':  A**H * X = B  (Conjugate transpose = Transpose)

    M

              M is INTEGER
              The number of rows of the matrix A.  M >= 0.

    N

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

    KL

              KL is INTEGER
              The number of subdiagonals within the band of A.  KL >= 0.

    KU

              KU is INTEGER
              The number of superdiagonals within the band of A.  KU >= 0.

    NRHS

              NRHS is INTEGER
              The number of columns of B.  NRHS >= 0.

    A

              A is DOUBLE PRECISION array, dimension (LDA,N)
              The original matrix A in band storage, stored in rows 1 to
              KL+KU+1.

    LDA

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

    X

              X is DOUBLE PRECISION 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.  If TRANS = 'N',
              LDX >= max(1,N); if TRANS = 'T' or 'C', LDX >= max(1,M).

    B

              B is DOUBLE PRECISION 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.  IF TRANS = 'N',
              LDB >= max(1,M); if TRANS = 'T' or 'C', LDB >= max(1,N).

    RWORK

              RWORK is DOUBLE PRECISION array, dimension (MAX(1,LRWORK)),
              where LRWORK >= M when TRANS = 'T' or 'C'; otherwise, RWORK
              is not referenced.

    RESID

              RESID is DOUBLE PRECISION
              The maximum over the number of right hand sides of
              norm(B - op(A)*X) / ( norm(op(A)) * norm(X) * EPS ).

Author
    Univ. of Tennessee

    Univ. of California Berkeley

    Univ. of Colorado Denver

    NAG Ltd.

Definition at line 147 of file dgbt02.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.