# spot03.f - Man Page

TESTING/LIN/spot03.f

## Synopsis

### Functions/Subroutines

subroutine spot03 (uplo, n, a, lda, ainv, ldainv, work, ldwork, rwork, rcond, resid)
SPOT03

## Function/Subroutine Documentation

### subroutine spot03 (character uplo, integer n, real, dimension( lda, * ) a, integer lda, real, dimension( ldainv, * ) ainv, integer ldainv, real, dimension( ldwork, * ) work, integer ldwork, real, dimension( * ) rwork, real rcond, real resid)

SPOT03

Purpose:

``` SPOT03 computes the residual for a symmetric matrix times its
inverse:
norm( I - A*AINV ) / ( N * norm(A) * norm(AINV) * 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.```

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)```

AINV

```          AINV is REAL array, dimension (LDAINV,N)
On entry, the inverse of the matrix A, stored as a symmetric
matrix in the same format as A.
In this version, AINV is expanded into a full matrix and
multiplied by A, so the opposing triangle of AINV will be
changed; i.e., if the upper triangular part of AINV is
stored, the lower triangular part will be used as work space.```

LDAINV

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

WORK

`          WORK is REAL array, dimension (LDWORK,N)`

LDWORK

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

RWORK

`          RWORK is REAL array, dimension (N)`

RCOND

```          RCOND is REAL
The reciprocal of the condition number of A, computed as
( 1/norm(A) ) / norm(AINV).```

RESID

```          RESID is REAL
norm(I - A*AINV) / ( N * norm(A) * norm(AINV) * EPS )```
Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 123 of file spot03.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

The man page spot03(3) is an alias of spot03.f(3).

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