CPOT03
Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..
November 2006
November 2006
Purpose
CPOT03 computes the residual for a Hermitian matrix times its
inverse:
norm( I - A*AINV ) / ( N * norm(A) * norm(AINV) * EPS ),
where EPS is the machine epsilon.
inverse:
norm( I - A*AINV ) / ( N * norm(A) * norm(AINV) * EPS ),
where EPS is the machine epsilon.
Arguments
| UPLO |
(input) CHARACTER*1
Specifies whether the upper or lower triangular part of the
Hermitian matrix A is stored: = 'U': Upper triangular = 'L': Lower triangular |
| N |
(input) INTEGER
The number of rows and columns of the matrix A. N >= 0.
|
| A |
(input) COMPLEX array, dimension (LDA,N)
The original Hermitian matrix A.
|
| LDA |
(input) INTEGER
The leading dimension of the array A. LDA >= max(1,N)
|
| AINV |
(input/output) COMPLEX array, dimension (LDAINV,N)
On entry, the inverse of the matrix A, stored as a Hermitian
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 |
(input) INTEGER
The leading dimension of the array AINV. LDAINV >= max(1,N).
|
| WORK |
(workspace) COMPLEX array, dimension (LDWORK,N)
|
| LDWORK |
(input) INTEGER
The leading dimension of the array WORK. LDWORK >= max(1,N).
|
| RWORK |
(workspace) REAL array, dimension (N)
|
| RCOND |
(output) REAL
The reciprocal of the condition number of A, computed as
( 1/norm(A) ) / norm(AINV). |
| RESID |
(output) REAL
norm(I - A*AINV) / ( N * norm(A) * norm(AINV) * EPS )
|