Library Functions Manual

NAME¶

hetri_3 - {he,sy}tri_3: inverse

SYNOPSIS¶

Functions¶

subroutine CHETRI_3 (uplo, n, a, lda, e, ipiv, work, lwork, info)
CHETRI_3 subroutine CSYTRI_3 (uplo, n, a, lda, e, ipiv, work, lwork, info)
CSYTRI_3 subroutine DSYTRI_3 (uplo, n, a, lda, e, ipiv, work, lwork, info)
DSYTRI_3 subroutine SSYTRI_3 (uplo, n, a, lda, e, ipiv, work, lwork, info)
SSYTRI_3 subroutine ZHETRI_3 (uplo, n, a, lda, e, ipiv, work, lwork, info)
ZHETRI_3 subroutine ZSYTRI_3 (uplo, n, a, lda, e, ipiv, work, lwork, info)
ZSYTRI_3

Detailed Description¶

Function Documentation¶

subroutine CHETRI_3 (character uplo, integer n, complex, dimension( lda, * ) a, integer lda, complex, dimension( * ) e, integer, dimension( * ) ipiv, complex, dimension( * ) work, integer lwork, integer info)¶

CHETRI_3

Purpose:

!> CHETRI_3 computes the inverse of a complex Hermitian indefinite
!> matrix A using the factorization computed by CHETRF_RK or CHETRF_BK:
!>
!>     A = P*U*D*(U**H)*(P**T) or A = P*L*D*(L**H)*(P**T),
!>
!> where U (or L) is unit upper (or lower) triangular matrix,
!> U**H (or L**H) is the conjugate of U (or L), P is a permutation
!> matrix, P**T is the transpose of P, and D is Hermitian and block
!> diagonal with 1-by-1 and 2-by-2 diagonal blocks.
!>
!> CHETRI_3 sets the leading dimension of the workspace  before calling
!> CHETRI_3X that actually computes the inverse.  This is the blocked
!> version of the algorithm, calling Level 3 BLAS.
!>

Parameters

UPLO

!>          UPLO is CHARACTER*1
!>          Specifies whether the details of the factorization are
!>          stored as an upper or lower triangular matrix.
!>          = 'U':  Upper triangle of A is stored;
!>          = 'L':  Lower triangle of A is stored.
!>

!>          N is INTEGER
!>          The order of the matrix A.  N >= 0.
!>

!>          A is COMPLEX array, dimension (LDA,N)
!>          On entry, diagonal of the block diagonal matrix D and
!>          factors U or L as computed by CHETRF_RK and CHETRF_BK:
!>            a) ONLY diagonal elements of the Hermitian block diagonal
!>               matrix D on the diagonal of A, i.e. D(k,k) = A(k,k);
!>               (superdiagonal (or subdiagonal) elements of D
!>                should be provided on entry in array E), and
!>            b) If UPLO = 'U': factor U in the superdiagonal part of A.
!>               If UPLO = 'L': factor L in the subdiagonal part of A.
!>
!>          On exit, if INFO = 0, the Hermitian 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.
!>

LDA

!>          LDA is INTEGER
!>          The leading dimension of the array A.  LDA >= max(1,N).
!>

!>          E is COMPLEX array, dimension (N)
!>          On entry, contains the superdiagonal (or subdiagonal)
!>          elements of the Hermitian block diagonal matrix D
!>          with 1-by-1 or 2-by-2 diagonal blocks, where
!>          If UPLO = 'U': E(i) = D(i-1,i),i=2:N, E(1) not referenced;
!>          If UPLO = 'L': E(i) = D(i+1,i),i=1:N-1, E(N) not referenced.
!>
!>          NOTE: For 1-by-1 diagonal block D(k), where
!>          1 <= k <= N, the element E(k) is not referenced in both
!>          UPLO = 'U' or UPLO = 'L' cases.
!>

IPIV

!>          IPIV is INTEGER array, dimension (N)
!>          Details of the interchanges and the block structure of D
!>          as determined by CHETRF_RK or CHETRF_BK.
!>

WORK

!>          WORK is COMPLEX array, dimension (N+NB+1)*(NB+3).
!>          On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
!>

LWORK

!>          LWORK is INTEGER
!>          The length of WORK. LWORK >= (N+NB+1)*(NB+3).
!>
!>          If LDWORK = -1, then a workspace query is assumed;
!>          the routine only calculates the optimal size of 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, D(i,i) = 0; the matrix is singular and its
!>               inverse could not be computed.
!>

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Contributors:

!>
!>  November 2017,  Igor Kozachenko,
!>                  Computer Science Division,
!>                  University of California, Berkeley
!>
!>

Definition at line 168 of file chetri_3.f.

subroutine CSYTRI_3 (character uplo, integer n, complex, dimension( lda, * ) a, integer lda, complex, dimension( * ) e, integer, dimension( * ) ipiv, complex, dimension( * ) work, integer lwork, integer info)¶

CSYTRI_3

Purpose:

!> CSYTRI_3 computes the inverse of a complex symmetric indefinite
!> matrix A using the factorization computed by CSYTRF_RK or CSYTRF_BK:
!>
!>     A = P*U*D*(U**T)*(P**T) or A = P*L*D*(L**T)*(P**T),
!>
!> where U (or L) is unit upper (or lower) triangular matrix,
!> U**T (or L**T) is the transpose of U (or L), P is a permutation
!> matrix, P**T is the transpose of P, and D is symmetric and block
!> diagonal with 1-by-1 and 2-by-2 diagonal blocks.
!>
!> CSYTRI_3 sets the leading dimension of the workspace  before calling
!> CSYTRI_3X that actually computes the inverse.  This is the blocked
!> version of the algorithm, calling Level 3 BLAS.
!>

Parameters

UPLO

!>          UPLO is CHARACTER*1
!>          Specifies whether the details of the factorization are
!>          stored as an upper or lower triangular matrix.
!>          = 'U':  Upper triangle of A is stored;
!>          = 'L':  Lower triangle of A is stored.
!>

!>          N is INTEGER
!>          The order of the matrix A.  N >= 0.
!>

!>          A is COMPLEX array, dimension (LDA,N)
!>          On entry, diagonal of the block diagonal matrix D and
!>          factors U or L as computed by CSYTRF_RK and CSYTRF_BK:
!>            a) ONLY diagonal elements of the symmetric block diagonal
!>               matrix D on the diagonal of A, i.e. D(k,k) = A(k,k);
!>               (superdiagonal (or subdiagonal) elements of D
!>                should be provided on entry in array E), and
!>            b) If UPLO = 'U': factor U in the superdiagonal part of A.
!>               If UPLO = 'L': factor L in the subdiagonal part of A.
!>
!>          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.
!>

LDA

!>          LDA is INTEGER
!>          The leading dimension of the array A.  LDA >= max(1,N).
!>

!>          E is COMPLEX array, dimension (N)
!>          On entry, contains the superdiagonal (or subdiagonal)
!>          elements of the symmetric block diagonal matrix D
!>          with 1-by-1 or 2-by-2 diagonal blocks, where
!>          If UPLO = 'U': E(i) = D(i-1,i),i=2:N, E(1) not referenced;
!>          If UPLO = 'L': E(i) = D(i+1,i),i=1:N-1, E(N) not referenced.
!>
!>          NOTE: For 1-by-1 diagonal block D(k), where
!>          1 <= k <= N, the element E(k) is not referenced in both
!>          UPLO = 'U' or UPLO = 'L' cases.
!>

IPIV

!>          IPIV is INTEGER array, dimension (N)
!>          Details of the interchanges and the block structure of D
!>          as determined by CSYTRF_RK or CSYTRF_BK.
!>

WORK

!>          WORK is COMPLEX array, dimension (N+NB+1)*(NB+3).
!>          On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
!>

LWORK

!>          LWORK is INTEGER
!>          The length of WORK. LWORK >= (N+NB+1)*(NB+3).
!>
!>          If LDWORK = -1, then a workspace query is assumed;
!>          the routine only calculates the optimal size of 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, D(i,i) = 0; the matrix is singular and its
!>               inverse could not be computed.
!>

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Contributors:

!>
!>  November 2017,  Igor Kozachenko,
!>                  Computer Science Division,
!>                  University of California, Berkeley
!>
!>

Definition at line 168 of file csytri_3.f.

subroutine DSYTRI_3 (character uplo, integer n, double precision, dimension( lda, * ) a, integer lda, double precision, dimension( * ) e, integer, dimension( * ) ipiv, double precision, dimension( * ) work, integer lwork, integer info)¶

DSYTRI_3

Purpose:

!> DSYTRI_3 computes the inverse of a real symmetric indefinite
!> matrix A using the factorization computed by DSYTRF_RK or DSYTRF_BK:
!>
!>     A = P*U*D*(U**T)*(P**T) or A = P*L*D*(L**T)*(P**T),
!>
!> where U (or L) is unit upper (or lower) triangular matrix,
!> U**T (or L**T) is the transpose of U (or L), P is a permutation
!> matrix, P**T is the transpose of P, and D is symmetric and block
!> diagonal with 1-by-1 and 2-by-2 diagonal blocks.
!>
!> DSYTRI_3 sets the leading dimension of the workspace  before calling
!> DSYTRI_3X that actually computes the inverse.  This is the blocked
!> version of the algorithm, calling Level 3 BLAS.
!>

Parameters

UPLO

!>          UPLO is CHARACTER*1
!>          Specifies whether the details of the factorization are
!>          stored as an upper or lower triangular matrix.
!>          = 'U':  Upper triangle of A is stored;
!>          = 'L':  Lower triangle of A is stored.
!>

!>          N is INTEGER
!>          The order of the matrix A.  N >= 0.
!>

!>          A is DOUBLE PRECISION array, dimension (LDA,N)
!>          On entry, diagonal of the block diagonal matrix D and
!>          factors U or L as computed by DSYTRF_RK and DSYTRF_BK:
!>            a) ONLY diagonal elements of the symmetric block diagonal
!>               matrix D on the diagonal of A, i.e. D(k,k) = A(k,k);
!>               (superdiagonal (or subdiagonal) elements of D
!>                should be provided on entry in array E), and
!>            b) If UPLO = 'U': factor U in the superdiagonal part of A.
!>               If UPLO = 'L': factor L in the subdiagonal part of A.
!>
!>          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.
!>

LDA

!>          LDA is INTEGER
!>          The leading dimension of the array A.  LDA >= max(1,N).
!>

!>          E is DOUBLE PRECISION array, dimension (N)
!>          On entry, contains the superdiagonal (or subdiagonal)
!>          elements of the symmetric block diagonal matrix D
!>          with 1-by-1 or 2-by-2 diagonal blocks, where
!>          If UPLO = 'U': E(i) = D(i-1,i),i=2:N, E(1) not referenced;
!>          If UPLO = 'L': E(i) = D(i+1,i),i=1:N-1, E(N) not referenced.
!>
!>          NOTE: For 1-by-1 diagonal block D(k), where
!>          1 <= k <= N, the element E(k) is not referenced in both
!>          UPLO = 'U' or UPLO = 'L' cases.
!>

IPIV

!>          IPIV is INTEGER array, dimension (N)
!>          Details of the interchanges and the block structure of D
!>          as determined by DSYTRF_RK or DSYTRF_BK.
!>

WORK

!>          WORK is DOUBLE PRECISION array, dimension (N+NB+1)*(NB+3).
!>          On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
!>

LWORK

!>          LWORK is INTEGER
!>          The length of WORK. LWORK >= (N+NB+1)*(NB+3).
!>
!>          If LDWORK = -1, then a workspace query is assumed;
!>          the routine only calculates the optimal size of 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, D(i,i) = 0; the matrix is singular and its
!>               inverse could not be computed.
!>

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Contributors:

!>
!>  November 2017,  Igor Kozachenko,
!>                  Computer Science Division,
!>                  University of California, Berkeley
!>
!>

Definition at line 168 of file dsytri_3.f.

subroutine SSYTRI_3 (character uplo, integer n, real, dimension( lda, * ) a, integer lda, real, dimension( * ) e, integer, dimension( * ) ipiv, real, dimension( * ) work, integer lwork, integer info)¶

SSYTRI_3

Purpose:

!> SSYTRI_3 computes the inverse of a real symmetric indefinite
!> matrix A using the factorization computed by SSYTRF_RK or SSYTRF_BK:
!>
!>     A = P*U*D*(U**T)*(P**T) or A = P*L*D*(L**T)*(P**T),
!>
!> where U (or L) is unit upper (or lower) triangular matrix,
!> U**T (or L**T) is the transpose of U (or L), P is a permutation
!> matrix, P**T is the transpose of P, and D is symmetric and block
!> diagonal with 1-by-1 and 2-by-2 diagonal blocks.
!>
!> SSYTRI_3 sets the leading dimension of the workspace  before calling
!> SSYTRI_3X that actually computes the inverse.  This is the blocked
!> version of the algorithm, calling Level 3 BLAS.
!>

Parameters

UPLO

!>          UPLO is CHARACTER*1
!>          Specifies whether the details of the factorization are
!>          stored as an upper or lower triangular matrix.
!>          = 'U':  Upper triangle of A is stored;
!>          = 'L':  Lower triangle of A is stored.
!>

!>          N is INTEGER
!>          The order of the matrix A.  N >= 0.
!>

!>          A is REAL array, dimension (LDA,N)
!>          On entry, diagonal of the block diagonal matrix D and
!>          factors U or L as computed by SSYTRF_RK and SSYTRF_BK:
!>            a) ONLY diagonal elements of the symmetric block diagonal
!>               matrix D on the diagonal of A, i.e. D(k,k) = A(k,k);
!>               (superdiagonal (or subdiagonal) elements of D
!>                should be provided on entry in array E), and
!>            b) If UPLO = 'U': factor U in the superdiagonal part of A.
!>               If UPLO = 'L': factor L in the subdiagonal part of A.
!>
!>          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.
!>

LDA

!>          LDA is INTEGER
!>          The leading dimension of the array A.  LDA >= max(1,N).
!>

!>          E is REAL array, dimension (N)
!>          On entry, contains the superdiagonal (or subdiagonal)
!>          elements of the symmetric block diagonal matrix D
!>          with 1-by-1 or 2-by-2 diagonal blocks, where
!>          If UPLO = 'U': E(i) = D(i-1,i),i=2:N, E(1) not referenced;
!>          If UPLO = 'L': E(i) = D(i+1,i),i=1:N-1, E(N) not referenced.
!>
!>          NOTE: For 1-by-1 diagonal block D(k), where
!>          1 <= k <= N, the element E(k) is not referenced in both
!>          UPLO = 'U' or UPLO = 'L' cases.
!>

IPIV

!>          IPIV is INTEGER array, dimension (N)
!>          Details of the interchanges and the block structure of D
!>          as determined by SSYTRF_RK or SSYTRF_BK.
!>

WORK

!>          WORK is REAL array, dimension (N+NB+1)*(NB+3).
!>          On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
!>

LWORK

!>          LWORK is INTEGER
!>          The length of WORK. LWORK >= (N+NB+1)*(NB+3).
!>
!>          If LDWORK = -1, then a workspace query is assumed;
!>          the routine only calculates the optimal size of 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, D(i,i) = 0; the matrix is singular and its
!>               inverse could not be computed.
!>

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Contributors:

!>
!>  November 2017,  Igor Kozachenko,
!>                  Computer Science Division,
!>                  University of California, Berkeley
!>
!>

Definition at line 168 of file ssytri_3.f.

subroutine ZHETRI_3 (character uplo, integer n, complex16, dimension( lda, ) a, integer lda, complex16, dimension( ) e, integer, dimension( * ) ipiv, complex16, dimension( ) work, integer lwork, integer info)¶

ZHETRI_3

Purpose:

!> ZHETRI_3 computes the inverse of a complex Hermitian indefinite
!> matrix A using the factorization computed by ZHETRF_RK or ZHETRF_BK:
!>
!>     A = P*U*D*(U**H)*(P**T) or A = P*L*D*(L**H)*(P**T),
!>
!> where U (or L) is unit upper (or lower) triangular matrix,
!> U**H (or L**H) is the conjugate of U (or L), P is a permutation
!> matrix, P**T is the transpose of P, and D is Hermitian and block
!> diagonal with 1-by-1 and 2-by-2 diagonal blocks.
!>
!> ZHETRI_3 sets the leading dimension of the workspace  before calling
!> ZHETRI_3X that actually computes the inverse.  This is the blocked
!> version of the algorithm, calling Level 3 BLAS.
!>

Parameters

UPLO

!>          UPLO is CHARACTER*1
!>          Specifies whether the details of the factorization are
!>          stored as an upper or lower triangular matrix.
!>          = 'U':  Upper triangle of A is stored;
!>          = 'L':  Lower triangle of A is stored.
!>

!>          N is INTEGER
!>          The order of the matrix A.  N >= 0.
!>

!>          A is COMPLEX*16 array, dimension (LDA,N)
!>          On entry, diagonal of the block diagonal matrix D and
!>          factors U or L as computed by ZHETRF_RK and ZHETRF_BK:
!>            a) ONLY diagonal elements of the Hermitian block diagonal
!>               matrix D on the diagonal of A, i.e. D(k,k) = A(k,k);
!>               (superdiagonal (or subdiagonal) elements of D
!>                should be provided on entry in array E), and
!>            b) If UPLO = 'U': factor U in the superdiagonal part of A.
!>               If UPLO = 'L': factor L in the subdiagonal part of A.
!>
!>          On exit, if INFO = 0, the Hermitian 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.
!>

LDA

!>          LDA is INTEGER
!>          The leading dimension of the array A.  LDA >= max(1,N).
!>

!>          E is COMPLEX*16 array, dimension (N)
!>          On entry, contains the superdiagonal (or subdiagonal)
!>          elements of the Hermitian block diagonal matrix D
!>          with 1-by-1 or 2-by-2 diagonal blocks, where
!>          If UPLO = 'U': E(i) = D(i-1,i),i=2:N, E(1) not referenced;
!>          If UPLO = 'L': E(i) = D(i+1,i),i=1:N-1, E(N) not referenced.
!>
!>          NOTE: For 1-by-1 diagonal block D(k), where
!>          1 <= k <= N, the element E(k) is not referenced in both
!>          UPLO = 'U' or UPLO = 'L' cases.
!>

IPIV

!>          IPIV is INTEGER array, dimension (N)
!>          Details of the interchanges and the block structure of D
!>          as determined by ZHETRF_RK or ZHETRF_BK.
!>

WORK

!>          WORK is COMPLEX*16 array, dimension (N+NB+1)*(NB+3).
!>          On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
!>

LWORK

!>          LWORK is INTEGER
!>          The length of WORK. LWORK >= (N+NB+1)*(NB+3).
!>
!>          If LDWORK = -1, then a workspace query is assumed;
!>          the routine only calculates the optimal size of 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, D(i,i) = 0; the matrix is singular and its
!>               inverse could not be computed.
!>

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Contributors:

!>
!>  November 2017,  Igor Kozachenko,
!>                  Computer Science Division,
!>                  University of California, Berkeley
!>
!>

Definition at line 168 of file zhetri_3.f.

subroutine ZSYTRI_3 (character uplo, integer n, complex16, dimension( lda, ) a, integer lda, complex16, dimension( ) e, integer, dimension( * ) ipiv, complex16, dimension( ) work, integer lwork, integer info)¶

ZSYTRI_3

Purpose:

!> ZSYTRI_3 computes the inverse of a complex symmetric indefinite
!> matrix A using the factorization computed by ZSYTRF_RK or ZSYTRF_BK:
!>
!>     A = P*U*D*(U**T)*(P**T) or A = P*L*D*(L**T)*(P**T),
!>
!> where U (or L) is unit upper (or lower) triangular matrix,
!> U**T (or L**T) is the transpose of U (or L), P is a permutation
!> matrix, P**T is the transpose of P, and D is symmetric and block
!> diagonal with 1-by-1 and 2-by-2 diagonal blocks.
!>
!> ZSYTRI_3 sets the leading dimension of the workspace  before calling
!> ZSYTRI_3X that actually computes the inverse.  This is the blocked
!> version of the algorithm, calling Level 3 BLAS.
!>

Parameters

UPLO

!>          UPLO is CHARACTER*1
!>          Specifies whether the details of the factorization are
!>          stored as an upper or lower triangular matrix.
!>          = 'U':  Upper triangle of A is stored;
!>          = 'L':  Lower triangle of A is stored.
!>

!>          N is INTEGER
!>          The order of the matrix A.  N >= 0.
!>

!>          A is COMPLEX*16 array, dimension (LDA,N)
!>          On entry, diagonal of the block diagonal matrix D and
!>          factors U or L as computed by ZSYTRF_RK and ZSYTRF_BK:
!>            a) ONLY diagonal elements of the symmetric block diagonal
!>               matrix D on the diagonal of A, i.e. D(k,k) = A(k,k);
!>               (superdiagonal (or subdiagonal) elements of D
!>                should be provided on entry in array E), and
!>            b) If UPLO = 'U': factor U in the superdiagonal part of A.
!>               If UPLO = 'L': factor L in the subdiagonal part of A.
!>
!>          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.
!>

LDA

!>          LDA is INTEGER
!>          The leading dimension of the array A.  LDA >= max(1,N).
!>

!>          E is COMPLEX*16 array, dimension (N)
!>          On entry, contains the superdiagonal (or subdiagonal)
!>          elements of the symmetric block diagonal matrix D
!>          with 1-by-1 or 2-by-2 diagonal blocks, where
!>          If UPLO = 'U': E(i) = D(i-1,i),i=2:N, E(1) not referenced;
!>          If UPLO = 'L': E(i) = D(i+1,i),i=1:N-1, E(N) not referenced.
!>
!>          NOTE: For 1-by-1 diagonal block D(k), where
!>          1 <= k <= N, the element E(k) is not referenced in both
!>          UPLO = 'U' or UPLO = 'L' cases.
!>

IPIV

!>          IPIV is INTEGER array, dimension (N)
!>          Details of the interchanges and the block structure of D
!>          as determined by ZSYTRF_RK or ZSYTRF_BK.
!>

WORK

!>          WORK is COMPLEX*16 array, dimension (N+NB+1)*(NB+3).
!>          On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
!>

LWORK

!>          LWORK is INTEGER
!>          The length of WORK. LWORK >= (N+NB+1)*(NB+3).
!>
!>          If LDWORK = -1, then a workspace query is assumed;
!>          the routine only calculates the optimal size of 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, D(i,i) = 0; the matrix is singular and its
!>               inverse could not be computed.
!>

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Contributors:

!>
!>  November 2017,  Igor Kozachenko,
!>                  Computer Science Division,
!>                  University of California, Berkeley
!>
!>

Definition at line 168 of file zsytri_3.f.

Author¶

Generated automatically by Doxygen for LAPACK from the source code.

Version 3.12.0

LAPACK

Source file:	hetri_3.3.en.gz (from lapack-man 3.12.0-160000.1.3)
Source last updated:	2024-11-04T16:48:43Z
Converted to HTML:	2025-03-25T08:55:27Z

NAME¶

SYNOPSIS¶

Functions¶

Detailed Description¶

Function Documentation¶

subroutine CHETRI_3 (character uplo, integer n, complex, dimension( lda, * ) a, integer lda, complex, dimension( * ) e, integer, dimension( * ) ipiv, complex, dimension( * ) work, integer lwork, integer info)¶

subroutine CSYTRI_3 (character uplo, integer n, complex, dimension( lda, * ) a, integer lda, complex, dimension( * ) e, integer, dimension( * ) ipiv, complex, dimension( * ) work, integer lwork, integer info)¶

subroutine DSYTRI_3 (character uplo, integer n, double precision, dimension( lda, * ) a, integer lda, double precision, dimension( * ) e, integer, dimension( * ) ipiv, double precision, dimension( * ) work, integer lwork, integer info)¶

subroutine SSYTRI_3 (character uplo, integer n, real, dimension( lda, * ) a, integer lda, real, dimension( * ) e, integer, dimension( * ) ipiv, real, dimension( * ) work, integer lwork, integer info)¶

subroutine ZHETRI_3 (character uplo, integer n, complex*16, dimension( lda, * ) a, integer lda, complex*16, dimension( * ) e, integer, dimension( * ) ipiv, complex*16, dimension( * ) work, integer lwork, integer info)¶

subroutine ZSYTRI_3 (character uplo, integer n, complex*16, dimension( lda, * ) a, integer lda, complex*16, dimension( * ) e, integer, dimension( * ) ipiv, complex*16, dimension( * ) work, integer lwork, integer info)¶

Author¶

subroutine ZHETRI_3 (character uplo, integer n, complex16, dimension( lda, ) a, integer lda, complex16, dimension( ) e, integer, dimension( * ) ipiv, complex16, dimension( ) work, integer lwork, integer info)¶

subroutine ZSYTRI_3 (character uplo, integer n, complex16, dimension( lda, ) a, integer lda, complex16, dimension( ) e, integer, dimension( * ) ipiv, complex16, dimension( ) work, integer lwork, integer info)¶