LAPACK
3.4.2
LAPACK: Linear Algebra PACKage
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Go to the source code of this file.
Functions/Subroutines | |
subroutine | chetri2 (UPLO, N, A, LDA, IPIV, WORK, LWORK, INFO) |
CHETRI2 |
subroutine chetri2 | ( | character | UPLO, |
integer | N, | ||
complex, dimension( lda, * ) | A, | ||
integer | LDA, | ||
integer, dimension( * ) | IPIV, | ||
complex, dimension( * ) | WORK, | ||
integer | LWORK, | ||
integer | INFO | ||
) |
CHETRI2
Download CHETRI2 + dependencies [TGZ] [ZIP] [TXT]CHETRI2 computes the inverse of a COMPLEX hermitian indefinite matrix A using the factorization A = U*D*U**T or A = L*D*L**T computed by CHETRF. CHETRI2 set the LEADING DIMENSION of the workspace before calling CHETRI2X that actually computes the inverse.
[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**T; = 'L': Lower triangular, form is A = L*D*L**T. |
[in] | N | N is INTEGER The order of the matrix A. N >= 0. |
[in,out] | A | A is COMPLEX array, dimension (LDA,N) On entry, the NB diagonal matrix D and the multipliers used to obtain the factor U or L as computed by CHETRF. On exit, if INFO = 0, the (symmetric) inverse of the original matrix. If UPLO = 'U', the upper triangular part of the inverse is formed and the part of A below the diagonal is not referenced; if UPLO = 'L' the lower triangular part of the inverse is formed and the part of A above the diagonal is not referenced. |
[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 NB structure of D as determined by CHETRF. |
[out] | WORK | WORK is COMPLEX array, dimension (N+NB+1)*(NB+3) |
[in] | LWORK | LWORK is INTEGER The dimension of the array WORK. WORK is size >= (N+NB+1)*(NB+3) If LDWORK = -1, then a workspace query is assumed; the routine calculates: - the optimal size of the WORK array, returns this value as the first entry of the WORK array, - and no error message related to LDWORK is issued by XERBLA. |
[out] | INFO | INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value > 0: if INFO = i, D(i,i) = 0; the matrix is singular and its inverse could not be computed. |
Definition at line 128 of file chetri2.f.