table of contents
hetrf_aa(3) | Library Functions Manual | hetrf_aa(3) |
NAME¶
hetrf_aa - {he,sy}trf_aa: triangular factor
SYNOPSIS¶
Functions¶
subroutine CHETRF_AA (uplo, n, a, lda, ipiv, work, lwork,
info)
CHETRF_AA subroutine CSYTRF_AA (uplo, n, a, lda, ipiv, work,
lwork, info)
CSYTRF_AA subroutine DSYTRF_AA (uplo, n, a, lda, ipiv, work,
lwork, info)
DSYTRF_AA subroutine SSYTRF_AA (uplo, n, a, lda, ipiv, work,
lwork, info)
SSYTRF_AA subroutine ZHETRF_AA (uplo, n, a, lda, ipiv, work,
lwork, info)
ZHETRF_AA subroutine ZSYTRF_AA (uplo, n, a, lda, ipiv, work,
lwork, info)
ZSYTRF_AA
Detailed Description¶
Function Documentation¶
subroutine CHETRF_AA (character uplo, integer n, complex, dimension( lda, * ) a, integer lda, integer, dimension( * ) ipiv, complex, dimension( * ) work, integer lwork, integer info)¶
CHETRF_AA
Purpose:
!> !> CHETRF_AA computes the factorization of a complex hermitian matrix A !> using the Aasen's algorithm. The form of the factorization is !> !> A = U**H*T*U or A = L*T*L**H !> !> where U (or L) is a product of permutation and unit upper (lower) !> triangular matrices, and T is a hermitian tridiagonal matrix. !> !> This is the blocked version of the algorithm, calling Level 3 BLAS. !>
Parameters
!> UPLO is CHARACTER*1 !> = 'U': Upper triangle of A is stored; !> = 'L': Lower triangle of A is stored. !>
N
!> N is INTEGER !> The order of the matrix A. N >= 0. !>
A
!> A is COMPLEX array, dimension (LDA,N) !> On entry, the hermitian matrix A. If UPLO = 'U', the leading !> N-by-N upper triangular part of A contains the upper !> triangular part of the matrix A, and the strictly lower !> triangular part of A is not referenced. If UPLO = 'L', the !> leading N-by-N lower triangular part of A contains the lower !> triangular part of the matrix A, and the strictly upper !> triangular part of A is not referenced. !> !> On exit, the tridiagonal matrix is stored in the diagonals !> and the subdiagonals of A just below (or above) the diagonals, !> and L is stored below (or above) the subdiagonals, when UPLO !> is 'L' (or 'U'). !>
LDA
!> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !>
IPIV
!> IPIV is INTEGER array, dimension (N) !> On exit, it contains the details of the interchanges, i.e., !> the row and column k of A were interchanged with the !> row and column IPIV(k). !>
WORK
!> WORK is COMPLEX array, dimension (MAX(1,LWORK)) !> On exit, if INFO = 0, WORK(1) returns the optimal LWORK. !>
LWORK
!> LWORK is INTEGER !> The length of WORK. LWORK >= 2*N. For optimum performance !> LWORK >= N*(1+NB), where NB is the optimal blocksize. !> !> If LWORK = -1, then a workspace query is assumed; the routine !> only 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 LWORK is issued by XERBLA. !>
INFO
!> INFO is INTEGER !> = 0: successful exit !> < 0: if INFO = -i, the i-th argument had an illegal value. !>
Author
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 131 of file chetrf_aa.f.
subroutine CSYTRF_AA (character uplo, integer n, complex, dimension( lda, * ) a, integer lda, integer, dimension( * ) ipiv, complex, dimension( * ) work, integer lwork, integer info)¶
CSYTRF_AA
Purpose:
!> !> CSYTRF_AA computes the factorization of a complex symmetric matrix A !> using the Aasen's algorithm. The form of the factorization is !> !> A = U**T*T*U or A = L*T*L**T !> !> where U (or L) is a product of permutation and unit upper (lower) !> triangular matrices, and T is a complex symmetric tridiagonal matrix. !> !> This is the blocked version of the algorithm, calling Level 3 BLAS. !>
Parameters
!> UPLO is CHARACTER*1 !> = 'U': Upper triangle of A is stored; !> = 'L': Lower triangle of A is stored. !>
N
!> N is INTEGER !> The order of the matrix A. N >= 0. !>
A
!> A is COMPLEX array, dimension (LDA,N) !> On entry, the symmetric matrix A. If UPLO = 'U', the leading !> N-by-N upper triangular part of A contains the upper !> triangular part of the matrix A, and the strictly lower !> triangular part of A is not referenced. If UPLO = 'L', the !> leading N-by-N lower triangular part of A contains the lower !> triangular part of the matrix A, and the strictly upper !> triangular part of A is not referenced. !> !> On exit, the tridiagonal matrix is stored in the diagonals !> and the subdiagonals of A just below (or above) the diagonals, !> and L is stored below (or above) the subdiagonals, when UPLO !> is 'L' (or 'U'). !>
LDA
!> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !>
IPIV
!> IPIV is INTEGER array, dimension (N) !> On exit, it contains the details of the interchanges, i.e., !> the row and column k of A were interchanged with the !> row and column IPIV(k). !>
WORK
!> WORK is COMPLEX array, dimension (MAX(1,LWORK)) !> On exit, if INFO = 0, WORK(1) returns the optimal LWORK. !>
LWORK
!> LWORK is INTEGER !> The length of WORK. LWORK >= MAX(1,2*N). For optimum performance !> LWORK >= N*(1+NB), where NB is the optimal blocksize. !> !> If LWORK = -1, then a workspace query is assumed; the routine !> only 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 LWORK is issued by XERBLA. !>
INFO
!> INFO is INTEGER !> = 0: successful exit !> < 0: if INFO = -i, the i-th argument had an illegal value. !>
Author
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 131 of file csytrf_aa.f.
subroutine DSYTRF_AA (character uplo, integer n, double precision, dimension( lda, * ) a, integer lda, integer, dimension( * ) ipiv, double precision, dimension( * ) work, integer lwork, integer info)¶
DSYTRF_AA
Purpose:
!> !> DSYTRF_AA computes the factorization of a real symmetric matrix A !> using the Aasen's algorithm. The form of the factorization is !> !> A = U**T*T*U or A = L*T*L**T !> !> where U (or L) is a product of permutation and unit upper (lower) !> triangular matrices, and T is a symmetric tridiagonal matrix. !> !> This is the blocked version of the algorithm, calling Level 3 BLAS. !>
Parameters
!> UPLO is CHARACTER*1 !> = 'U': Upper triangle of A is stored; !> = 'L': Lower triangle of A is stored. !>
N
!> N is INTEGER !> The order of the matrix A. N >= 0. !>
A
!> A is DOUBLE PRECISION array, dimension (LDA,N) !> On entry, the symmetric matrix A. If UPLO = 'U', the leading !> N-by-N upper triangular part of A contains the upper !> triangular part of the matrix A, and the strictly lower !> triangular part of A is not referenced. If UPLO = 'L', the !> leading N-by-N lower triangular part of A contains the lower !> triangular part of the matrix A, and the strictly upper !> triangular part of A is not referenced. !> !> On exit, the tridiagonal matrix is stored in the diagonals !> and the subdiagonals of A just below (or above) the diagonals, !> and L is stored below (or above) the subdiagonals, when UPLO !> is 'L' (or 'U'). !>
LDA
!> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !>
IPIV
!> IPIV is INTEGER array, dimension (N) !> On exit, it contains the details of the interchanges, i.e., !> the row and column k of A were interchanged with the !> row and column IPIV(k). !>
WORK
!> WORK is DOUBLE PRECISION array, dimension (MAX(1,LWORK)) !> On exit, if INFO = 0, WORK(1) returns the optimal LWORK. !>
LWORK
!> LWORK is INTEGER !> The length of WORK. LWORK >= MAX(1,2*N). For optimum performance !> LWORK >= N*(1+NB), where NB is the optimal blocksize. !> !> If LWORK = -1, then a workspace query is assumed; the routine !> only 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 LWORK is issued by XERBLA. !>
INFO
!> INFO is INTEGER !> = 0: successful exit !> < 0: if INFO = -i, the i-th argument had an illegal value. !>
Author
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 131 of file dsytrf_aa.f.
subroutine SSYTRF_AA (character uplo, integer n, real, dimension( lda, * ) a, integer lda, integer, dimension( * ) ipiv, real, dimension( * ) work, integer lwork, integer info)¶
SSYTRF_AA
Purpose:
!> !> SSYTRF_AA computes the factorization of a real symmetric matrix A !> using the Aasen's algorithm. The form of the factorization is !> !> A = U**T*T*U or A = L*T*L**T !> !> where U (or L) is a product of permutation and unit upper (lower) !> triangular matrices, and T is a symmetric tridiagonal matrix. !> !> This is the blocked version of the algorithm, calling Level 3 BLAS. !>
Parameters
!> UPLO is CHARACTER*1 !> = 'U': Upper triangle of A is stored; !> = 'L': Lower triangle of A is stored. !>
N
!> N is INTEGER !> The order of the matrix A. N >= 0. !>
A
!> A is REAL array, dimension (LDA,N) !> On entry, the symmetric matrix A. If UPLO = 'U', the leading !> N-by-N upper triangular part of A contains the upper !> triangular part of the matrix A, and the strictly lower !> triangular part of A is not referenced. If UPLO = 'L', the !> leading N-by-N lower triangular part of A contains the lower !> triangular part of the matrix A, and the strictly upper !> triangular part of A is not referenced. !> !> On exit, the tridiagonal matrix is stored in the diagonals !> and the subdiagonals of A just below (or above) the diagonals, !> and L is stored below (or above) the subdiagonals, when UPLO !> is 'L' (or 'U'). !>
LDA
!> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !>
IPIV
!> IPIV is INTEGER array, dimension (N) !> On exit, it contains the details of the interchanges, i.e., !> the row and column k of A were interchanged with the !> row and column IPIV(k). !>
WORK
!> WORK is REAL array, dimension (MAX(1,LWORK)) !> On exit, if INFO = 0, WORK(1) returns the optimal LWORK. !>
LWORK
!> LWORK is INTEGER !> The length of WORK. LWORK >= MAX(1,2*N). For optimum performance !> LWORK >= N*(1+NB), where NB is the optimal blocksize. !> !> If LWORK = -1, then a workspace query is assumed; the routine !> only 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 LWORK is issued by XERBLA. !>
INFO
!> INFO is INTEGER !> = 0: successful exit !> < 0: if INFO = -i, the i-th argument had an illegal value. !>
Author
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 131 of file ssytrf_aa.f.
subroutine ZHETRF_AA (character uplo, integer n, complex*16, dimension( lda, * ) a, integer lda, integer, dimension( * ) ipiv, complex*16, dimension( * ) work, integer lwork, integer info)¶
ZHETRF_AA
Purpose:
!> !> ZHETRF_AA computes the factorization of a complex hermitian matrix A !> using the Aasen's algorithm. The form of the factorization is !> !> A = U**H*T*U or A = L*T*L**H !> !> where U (or L) is a product of permutation and unit upper (lower) !> triangular matrices, and T is a hermitian tridiagonal matrix. !> !> This is the blocked version of the algorithm, calling Level 3 BLAS. !>
Parameters
!> UPLO is CHARACTER*1 !> = 'U': Upper triangle of A is stored; !> = 'L': Lower triangle of A is stored. !>
N
!> N is INTEGER !> The order of the matrix A. N >= 0. !>
A
!> A is COMPLEX*16 array, dimension (LDA,N) !> On entry, the hermitian matrix A. If UPLO = 'U', the leading !> N-by-N upper triangular part of A contains the upper !> triangular part of the matrix A, and the strictly lower !> triangular part of A is not referenced. If UPLO = 'L', the !> leading N-by-N lower triangular part of A contains the lower !> triangular part of the matrix A, and the strictly upper !> triangular part of A is not referenced. !> !> On exit, the tridiagonal matrix is stored in the diagonals !> and the subdiagonals of A just below (or above) the diagonals, !> and L is stored below (or above) the subdiagonals, when UPLO !> is 'L' (or 'U'). !>
LDA
!> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !>
IPIV
!> IPIV is INTEGER array, dimension (N) !> On exit, it contains the details of the interchanges, i.e., !> the row and column k of A were interchanged with the !> row and column IPIV(k). !>
WORK
!> WORK is COMPLEX*16 array, dimension (MAX(1,LWORK)) !> On exit, if INFO = 0, WORK(1) returns the optimal LWORK. !>
LWORK
!> LWORK is INTEGER !> The length of WORK. LWORK >= MAX(1,2*N). For optimum performance !> LWORK >= N*(1+NB), where NB is the optimal blocksize. !> !> If LWORK = -1, then a workspace query is assumed; the routine !> only 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 LWORK is issued by XERBLA. !>
INFO
!> INFO is INTEGER !> = 0: successful exit !> < 0: if INFO = -i, the i-th argument had an illegal value. !>
Author
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 131 of file zhetrf_aa.f.
subroutine ZSYTRF_AA (character uplo, integer n, complex*16, dimension( lda, * ) a, integer lda, integer, dimension( * ) ipiv, complex*16, dimension( * ) work, integer lwork, integer info)¶
ZSYTRF_AA
Purpose:
!> !> ZSYTRF_AA computes the factorization of a complex symmetric matrix A !> using the Aasen's algorithm. The form of the factorization is !> !> A = U**T*T*U or A = L*T*L**T !> !> where U (or L) is a product of permutation and unit upper (lower) !> triangular matrices, and T is a complex symmetric tridiagonal matrix. !> !> This is the blocked version of the algorithm, calling Level 3 BLAS. !>
Parameters
!> UPLO is CHARACTER*1 !> = 'U': Upper triangle of A is stored; !> = 'L': Lower triangle of A is stored. !>
N
!> N is INTEGER !> The order of the matrix A. N >= 0. !>
A
!> A is COMPLEX*16 array, dimension (LDA,N) !> On entry, the symmetric matrix A. If UPLO = 'U', the leading !> N-by-N upper triangular part of A contains the upper !> triangular part of the matrix A, and the strictly lower !> triangular part of A is not referenced. If UPLO = 'L', the !> leading N-by-N lower triangular part of A contains the lower !> triangular part of the matrix A, and the strictly upper !> triangular part of A is not referenced. !> !> On exit, the tridiagonal matrix is stored in the diagonals !> and the subdiagonals of A just below (or above) the diagonals, !> and L is stored below (or above) the subdiagonals, when UPLO !> is 'L' (or 'U'). !>
LDA
!> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !>
IPIV
!> IPIV is INTEGER array, dimension (N) !> On exit, it contains the details of the interchanges, i.e., !> the row and column k of A were interchanged with the !> row and column IPIV(k). !>
WORK
!> WORK is COMPLEX*16 array, dimension (MAX(1,LWORK)) !> On exit, if INFO = 0, WORK(1) returns the optimal LWORK. !>
LWORK
!> LWORK is INTEGER !> The length of WORK. LWORK >=MAX(1,2*N). For optimum performance !> LWORK >= N*(1+NB), where NB is the optimal blocksize. !> !> If LWORK = -1, then a workspace query is assumed; the routine !> only 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 LWORK is issued by XERBLA. !>
INFO
!> INFO is INTEGER !> = 0: successful exit !> < 0: if INFO = -i, the i-th argument had an illegal value. !>
Author
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 131 of file zsytrf_aa.f.
Author¶
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