Visible to Intel only — GUID: GUID-50312D46-C692-464B-889F-CC56E144F496
Visible to Intel only — GUID: GUID-50312D46-C692-464B-889F-CC56E144F496
?hetri_rook
Computes the inverse of a complex Hermitian matrix using U*D*UH or L*D*LH bounded Bunch-Kaufman factorization.
Syntax
call chetri_rook( uplo, n, a, lda, ipiv, work, info )
call zhetri_rook( uplo, n, a, lda, ipiv, work, info )
call hetri_rook( a, ipiv [,uplo] [,info] )
Include Files
- mkl.fi, lapack.f90
Description
The routine computes the inverse inv(A) of a complex Hermitian matrix A. Before calling this routine, call ?hetrf_rook to factorize A.
Input Parameters
uplo |
CHARACTER*1. Must be 'U' or 'L'. Indicates how the input matrix A has been factored: If uplo = 'U', the array a stores the factorization A = U*D*UH. If uplo = 'L', the array a stores the factorization A = L*D*LH. |
n |
INTEGER. The order of the matrix A; n≥ 0. |
a, work |
COMPLEX for chetri_rook DOUBLE COMPLEX for zhetri_rook. Arrays: a(lda,*) contains the factorization of the matrix A, as returned by ?hetrf_rook. The second dimension of a must be at least max(1,n). work(*) is a workspace array. The dimension of work must be at least max(1,n). |
lda |
INTEGER. The leading dimension of a; lda≥ max(1, n). |
ipiv |
INTEGER. Array, size at least max(1, n). The ipiv array, as returned by ?hetrf_rook. |
Output Parameters
a |
Overwritten by the n-by-n matrix inv(A). |
info |
INTEGER. If info = 0, the execution is successful. If info = -i, the i-th parameter had an illegal value. If info = i, the i-th diagonal element of D is zero, D is singular, and the inversion could not be completed. |
LAPACK 95 Interface Notes
Routines in Fortran 95 interface have fewer arguments in the calling sequence than their FORTRAN 77 counterparts. For general conventions applied to skip redundant or reconstructible arguments, see LAPACK 95 Interface Conventions.
Specific details for the routine hetri_rook interface are as follows:
a |
Holds the matrix A of size (n,n). |
ipiv |
Holds the vector of length n. |
uplo |
Must be 'U' or 'L'. The default value is 'U'. |
Application Notes
The total number of floating-point operations is approximately (8/3)n3 for complex flavors.
The real counterpart of this routine is ?sytri_rook.