table of contents
hetrf_aa_2stage(3) | Library Functions Manual | hetrf_aa_2stage(3) |
NAME¶
hetrf_aa_2stage - {he,sy}trf_aa_2stage: triangular factor
SYNOPSIS¶
Functions¶
subroutine CHETRF_AA_2STAGE (uplo, n, a, lda, tb, ltb,
ipiv, ipiv2, work, lwork, info)
CHETRF_AA_2STAGE subroutine CSYTRF_AA_2STAGE (uplo, n, a, lda,
tb, ltb, ipiv, ipiv2, work, lwork, info)
CSYTRF_AA_2STAGE subroutine DSYTRF_AA_2STAGE (uplo, n, a, lda,
tb, ltb, ipiv, ipiv2, work, lwork, info)
DSYTRF_AA_2STAGE subroutine SSYTRF_AA_2STAGE (uplo, n, a, lda,
tb, ltb, ipiv, ipiv2, work, lwork, info)
SSYTRF_AA_2STAGE subroutine ZHETRF_AA_2STAGE (uplo, n, a, lda,
tb, ltb, ipiv, ipiv2, work, lwork, info)
ZHETRF_AA_2STAGE subroutine ZSYTRF_AA_2STAGE (uplo, n, a, lda,
tb, ltb, ipiv, ipiv2, work, lwork, info)
ZSYTRF_AA_2STAGE
Detailed Description¶
Function Documentation¶
subroutine CHETRF_AA_2STAGE (character uplo, integer n, complex, dimension( lda, * ) a, integer lda, complex, dimension( * ) tb, integer ltb, integer, dimension( * ) ipiv, integer, dimension( * ) ipiv2, complex, dimension( * ) work, integer lwork, integer info)¶
CHETRF_AA_2STAGE
Purpose:
!> !> CHETRF_AA_2STAGE computes the factorization of a real hermitian 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 hermitian band matrix with the !> bandwidth of NB (NB is internally selected and stored in TB( 1 ), and T is !> LU factorized with partial pivoting). !> !> 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, L is stored below (or above) the subdiagonal blocks, !> when UPLO is 'L' (or 'U'). !>
LDA
!> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !>
TB
!> TB is COMPLEX array, dimension (LTB) !> On exit, details of the LU factorization of the band matrix. !>
LTB
!> LTB is INTEGER !> The size of the array TB. LTB >= 4*N, internally !> used to select NB such that LTB >= (3*NB+1)*N. !> !> If LTB = -1, then a workspace query is assumed; the !> routine only calculates the optimal size of LTB, !> returns this value as the first entry of TB, and !> no error message related to LTB is issued by XERBLA. !>
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). !>
IPIV2
!> IPIV2 is INTEGER array, dimension (N) !> On exit, it contains the details of the interchanges, i.e., !> the row and column k of T were interchanged with the !> row and column IPIV(k). !>
WORK
!> WORK is COMPLEX workspace of size LWORK !>
LWORK
!> LWORK is INTEGER !> The size of WORK. LWORK >= N, internally used to select NB !> such that LWORK >= N*NB. !> !> 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. !> > 0: if INFO = i, band LU factorization failed on i-th column !>
Author
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 158 of file chetrf_aa_2stage.f.
subroutine CSYTRF_AA_2STAGE (character uplo, integer n, complex, dimension( lda, * ) a, integer lda, complex, dimension( * ) tb, integer ltb, integer, dimension( * ) ipiv, integer, dimension( * ) ipiv2, complex, dimension( * ) work, integer lwork, integer info)¶
CSYTRF_AA_2STAGE
Purpose:
!> !> CSYTRF_AA_2STAGE 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 band matrix with the !> bandwidth of NB (NB is internally selected and stored in TB( 1 ), and T is !> LU factorized with partial pivoting). !> !> 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, L is stored below (or above) the subdiagonal blocks, !> when UPLO is 'L' (or 'U'). !>
LDA
!> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !>
TB
!> TB is COMPLEX array, dimension (LTB) !> On exit, details of the LU factorization of the band matrix. !>
LTB
!> LTB is INTEGER !> The size of the array TB. LTB >= 4*N, internally !> used to select NB such that LTB >= (3*NB+1)*N. !> !> If LTB = -1, then a workspace query is assumed; the !> routine only calculates the optimal size of LTB, !> returns this value as the first entry of TB, and !> no error message related to LTB is issued by XERBLA. !>
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). !>
IPIV2
!> IPIV2 is INTEGER array, dimension (N) !> On exit, it contains the details of the interchanges, i.e., !> the row and column k of T were interchanged with the !> row and column IPIV(k). !>
WORK
!> WORK is COMPLEX workspace of size LWORK !>
LWORK
!> LWORK is INTEGER !> The size of WORK. LWORK >= N, internally used to select NB !> such that LWORK >= N*NB. !> !> 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. !> > 0: if INFO = i, band LU factorization failed on i-th column !>
Author
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 158 of file csytrf_aa_2stage.f.
subroutine DSYTRF_AA_2STAGE (character uplo, integer n, double precision, dimension( lda, * ) a, integer lda, double precision, dimension( * ) tb, integer ltb, integer, dimension( * ) ipiv, integer, dimension( * ) ipiv2, double precision, dimension( * ) work, integer lwork, integer info)¶
DSYTRF_AA_2STAGE
Purpose:
!> !> DSYTRF_AA_2STAGE 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 band matrix with the !> bandwidth of NB (NB is internally selected and stored in TB( 1 ), and T is !> LU factorized with partial pivoting). !> !> 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, L is stored below (or above) the subdiagonal blocks, !> when UPLO is 'L' (or 'U'). !>
LDA
!> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !>
TB
!> TB is DOUBLE PRECISION array, dimension (LTB) !> On exit, details of the LU factorization of the band matrix. !>
LTB
!> LTB is INTEGER !> The size of the array TB. LTB >= 4*N, internally !> used to select NB such that LTB >= (3*NB+1)*N. !> !> If LTB = -1, then a workspace query is assumed; the !> routine only calculates the optimal size of LTB, !> returns this value as the first entry of TB, and !> no error message related to LTB is issued by XERBLA. !>
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). !>
IPIV2
!> IPIV2 is INTEGER array, dimension (N) !> On exit, it contains the details of the interchanges, i.e., !> the row and column k of T were interchanged with the !> row and column IPIV2(k). !>
WORK
!> WORK is DOUBLE PRECISION workspace of size LWORK !>
LWORK
!> LWORK is INTEGER !> The size of WORK. LWORK >= N, internally used to select NB !> such that LWORK >= N*NB. !> !> 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. !> > 0: if INFO = i, band LU factorization failed on i-th column !>
Author
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 158 of file dsytrf_aa_2stage.f.
subroutine SSYTRF_AA_2STAGE (character uplo, integer n, real, dimension( lda, * ) a, integer lda, real, dimension( * ) tb, integer ltb, integer, dimension( * ) ipiv, integer, dimension( * ) ipiv2, real, dimension( * ) work, integer lwork, integer info)¶
SSYTRF_AA_2STAGE
Purpose:
!> !> SSYTRF_AA_2STAGE 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 band matrix with the !> bandwidth of NB (NB is internally selected and stored in TB( 1 ), and T is !> LU factorized with partial pivoting). !> !> 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, L is stored below (or above) the subdiagonal blocks, !> when UPLO is 'L' (or 'U'). !>
LDA
!> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !>
TB
!> TB is REAL array, dimension (LTB) !> On exit, details of the LU factorization of the band matrix. !>
LTB
!> LTB is INTEGER !> The size of the array TB. LTB >= 4*N, internally !> used to select NB such that LTB >= (3*NB+1)*N. !> !> If LTB = -1, then a workspace query is assumed; the !> routine only calculates the optimal size of LTB, !> returns this value as the first entry of TB, and !> no error message related to LTB is issued by XERBLA. !>
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). !>
IPIV2
!> IPIV2 is INTEGER array, dimension (N) !> On exit, it contains the details of the interchanges, i.e., !> the row and column k of T were interchanged with the !> row and column IPIV(k). !>
WORK
!> WORK is REAL workspace of size LWORK !>
LWORK
!> LWORK is INTEGER !> The size of WORK. LWORK >= N, internally used to select NB !> such that LWORK >= N*NB. !> !> 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. !> > 0: if INFO = i, band LU factorization failed on i-th column !>
Author
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 158 of file ssytrf_aa_2stage.f.
subroutine ZHETRF_AA_2STAGE (character uplo, integer n, complex*16, dimension( lda, * ) a, integer lda, complex*16, dimension( * ) tb, integer ltb, integer, dimension( * ) ipiv, integer, dimension( * ) ipiv2, complex*16, dimension( * ) work, integer lwork, integer info)¶
ZHETRF_AA_2STAGE
Purpose:
!> !> ZHETRF_AA_2STAGE computes the factorization of a double 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 band matrix with the !> bandwidth of NB (NB is internally selected and stored in TB( 1 ), and T is !> LU factorized with partial pivoting). !> !> 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, L is stored below (or above) the subdiagonal blocks, !> when UPLO is 'L' (or 'U'). !>
LDA
!> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !>
TB
!> TB is COMPLEX*16 array, dimension (LTB) !> On exit, details of the LU factorization of the band matrix. !>
LTB
!> LTB is INTEGER !> The size of the array TB. LTB >= 4*N, internally !> used to select NB such that LTB >= (3*NB+1)*N. !> !> If LTB = -1, then a workspace query is assumed; the !> routine only calculates the optimal size of LTB, !> returns this value as the first entry of TB, and !> no error message related to LTB is issued by XERBLA. !>
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). !>
IPIV2
!> IPIV2 is INTEGER array, dimension (N) !> On exit, it contains the details of the interchanges, i.e., !> the row and column k of T were interchanged with the !> row and column IPIV(k). !>
WORK
!> WORK is COMPLEX*16 workspace of size LWORK !>
LWORK
!> LWORK is INTEGER !> The size of WORK. LWORK >= N, internally used to select NB !> such that LWORK >= N*NB. !> !> 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. !> > 0: if INFO = i, band LU factorization failed on i-th column !>
Author
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 158 of file zhetrf_aa_2stage.f.
subroutine ZSYTRF_AA_2STAGE (character uplo, integer n, complex*16, dimension( lda, * ) a, integer lda, complex*16, dimension( * ) tb, integer ltb, integer, dimension( * ) ipiv, integer, dimension( * ) ipiv2, complex*16, dimension( * ) work, integer lwork, integer info)¶
ZSYTRF_AA_2STAGE
Purpose:
!> !> ZSYTRF_AA_2STAGE 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 band matrix with the !> bandwidth of NB (NB is internally selected and stored in TB( 1 ), and T is !> LU factorized with partial pivoting). !> !> 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, L is stored below (or above) the subdiagonal blocks, !> when UPLO is 'L' (or 'U'). !>
LDA
!> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !>
TB
!> TB is COMPLEX*16 array, dimension (LTB) !> On exit, details of the LU factorization of the band matrix. !>
LTB
!> LTB is INTEGER !> The size of the array TB. LTB >= 4*N, internally !> used to select NB such that LTB >= (3*NB+1)*N. !> !> If LTB = -1, then a workspace query is assumed; the !> routine only calculates the optimal size of LTB, !> returns this value as the first entry of TB, and !> no error message related to LTB is issued by XERBLA. !>
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). !>
IPIV2
!> IPIV2 is INTEGER array, dimension (N) !> On exit, it contains the details of the interchanges, i.e., !> the row and column k of T were interchanged with the !> row and column IPIV(k). !>
WORK
!> WORK is COMPLEX*16 workspace of size LWORK !>
LWORK
!> LWORK is INTEGER !> The size of WORK. LWORK >= N, internally used to select NB !> such that LWORK >= N*NB. !> !> 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. !> > 0: if INFO = i, band LU factorization failed on i-th column !>
Author
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 158 of file zsytrf_aa_2stage.f.
Author¶
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