# dpot03.f - Man Page

TESTING/LIN/dpot03.f

## Synopsis

### Functions/Subroutines

subroutine **dpot03** (uplo, n, a, lda, ainv, ldainv, work, ldwork, rwork, rcond, resid)**DPOT03**

## Function/Subroutine Documentation

### subroutine dpot03 (character uplo, integer n, double precision, dimension( lda, * ) a, integer lda, double precision, dimension( ldainv, * ) ainv, integer ldainv, double precision, dimension( ldwork, * ) work, integer ldwork, double precision, dimension( * ) rwork, double precision rcond, double precision resid)

**DPOT03**

**Purpose:**

DPOT03 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 DOUBLE PRECISION 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 DOUBLE PRECISION 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 DOUBLE PRECISION array, dimension (LDWORK,N)

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

*RWORK*RWORK is DOUBLE PRECISION array, dimension (N)

*RCOND*RCOND is DOUBLE PRECISION The reciprocal of the condition number of A, computed as ( 1/norm(A) ) / norm(AINV).

*RESID*RESID is DOUBLE PRECISION 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 **dpot03.f**.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

The man page dpot03(3) is an alias of dpot03.f(3).

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