TESTING/LIN/spbt02.f(3)    Library Functions Manual    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.

LAPACK                          Version 3.12.0         TESTING/LIN/spbt02.f(3)