LAPACK
3.6.1
LAPACK: Linear Algebra PACKage
|
subroutine zhecon | ( | character | UPLO, |
integer | N, | ||
complex*16, dimension( lda, * ) | A, | ||
integer | LDA, | ||
integer, dimension( * ) | IPIV, | ||
double precision | ANORM, | ||
double precision | RCOND, | ||
complex*16, dimension( * ) | WORK, | ||
integer | INFO | ||
) |
ZHECON
Download ZHECON + dependencies [TGZ] [ZIP] [TXT]
ZHECON estimates the reciprocal of the condition number of a complex Hermitian matrix A using the factorization A = U*D*U**H or A = L*D*L**H computed by ZHETRF. An estimate is obtained for norm(inv(A)), and the reciprocal of the condition number is computed as RCOND = 1 / (ANORM * norm(inv(A))).
[in] | UPLO | UPLO is CHARACTER*1 Specifies whether the details of the factorization are stored as an upper or lower triangular matrix. = 'U': Upper triangular, form is A = U*D*U**H; = 'L': Lower triangular, form is A = L*D*L**H. |
[in] | N | N is INTEGER The order of the matrix A. N >= 0. |
[in] | A | A is COMPLEX*16 array, dimension (LDA,N) The block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by ZHETRF. |
[in] | LDA | LDA is INTEGER The leading dimension of the array A. LDA >= max(1,N). |
[in] | IPIV | IPIV is INTEGER array, dimension (N) Details of the interchanges and the block structure of D as determined by ZHETRF. |
[in] | ANORM | ANORM is DOUBLE PRECISION The 1-norm of the original matrix A. |
[out] | RCOND | RCOND is DOUBLE PRECISION The reciprocal of the condition number of the matrix A, computed as RCOND = 1/(ANORM * AINVNM), where AINVNM is an estimate of the 1-norm of inv(A) computed in this routine. |
[out] | WORK | WORK is COMPLEX*16 array, dimension (2*N) |
[out] | INFO | INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value |
Definition at line 127 of file zhecon.f.