# spot02.f - Man Page

TESTING/LIN/spot02.f

## Synopsis

### Functions/Subroutines

subroutine spot02 (uplo, n, nrhs, a, lda, x, ldx, b, ldb, rwork, resid)
SPOT02

## Function/Subroutine Documentation

### subroutine spot02 (character uplo, integer n, 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)

SPOT02

Purpose:

``` SPOT02 computes the residual for the solution of a symmetric system
of linear equations  A*x = b:

RESID = norm(B - A*X) / ( norm(A) * norm(X) * EPS ),

where EPS is the machine epsilon.```
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.```

NRHS

```          NRHS is INTEGER
The number of columns of B, the matrix of right hand sides.
NRHS >= 0.```

A

```          A is REAL array, dimension (LDA,N)
The original symmetric matrix A.```

LDA

```          LDA is INTEGER
The leading dimension of the array A.  LDA >= max(1,N)```

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 125 of file spot02.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

The man page spot02(3) is an alias of spot02.f(3).

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