spbt02.f - Man Page

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

NAG Ltd.

Definition at line 134 of file spbt02.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

The man page spbt02(3) is an alias of spbt02.f(3).

Tue Nov 28 2023 12:08:43 Version 3.12.0 LAPACK