LAPACK 3.12.0
LAPACK: Linear Algebra PACKage
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◆ zsyconvf_rook()

subroutine zsyconvf_rook ( character uplo,
character way,
integer n,
complex*16, dimension( lda, * ) a,
integer lda,
complex*16, dimension( * ) e,
integer, dimension( * ) ipiv,
integer info )

ZSYCONVF_ROOK

Download ZSYCONVF_ROOK + dependencies [TGZ] [ZIP] [TXT]

Purpose:
!> If parameter WAY = 'C':
!> ZSYCONVF_ROOK converts the factorization output format used in
!> ZSYTRF_ROOK provided on entry in parameter A into the factorization
!> output format used in ZSYTRF_RK (or ZSYTRF_BK) that is stored
!> on exit in parameters A and E. IPIV format for ZSYTRF_ROOK and
!> ZSYTRF_RK (or ZSYTRF_BK) is the same and is not converted.
!>
!> If parameter WAY = 'R':
!> ZSYCONVF_ROOK performs the conversion in reverse direction, i.e.
!> converts the factorization output format used in ZSYTRF_RK
!> (or ZSYTRF_BK) provided on entry in parameters A and E into
!> the factorization output format used in ZSYTRF_ROOK that is stored
!> on exit in parameter A. IPIV format for ZSYTRF_ROOK and
!> ZSYTRF_RK (or ZSYTRF_BK) is the same and is not converted.
!>
!> ZSYCONVF_ROOK can also convert in Hermitian matrix case, i.e. between
!> formats used in ZHETRF_ROOK and ZHETRF_RK (or ZHETRF_BK).
!>
Parameters
[in]UPLO
!>          UPLO is CHARACTER*1
!>          Specifies whether the details of the factorization are
!>          stored as an upper or lower triangular matrix A.
!>          = 'U':  Upper triangular
!>          = 'L':  Lower triangular
!>
[in]WAY
!>          WAY is CHARACTER*1
!>          = 'C': Convert
!>          = 'R': Revert
!>
[in]N
!>          N is INTEGER
!>          The order of the matrix A.  N >= 0.
!>
[in,out]A
!>          A is COMPLEX*16 array, dimension (LDA,N)
!>
!>          1) If WAY ='C':
!>
!>          On entry, contains factorization details in format used in
!>          ZSYTRF_ROOK:
!>            a) all elements of the symmetric block diagonal
!>               matrix D on the diagonal of A and on superdiagonal
!>               (or subdiagonal) of A, and
!>            b) If UPLO = 'U': multipliers used to obtain factor U
!>               in the superdiagonal part of A.
!>               If UPLO = 'L': multipliers used to obtain factor L
!>               in the superdiagonal part of A.
!>
!>          On exit, contains factorization details in format used in
!>          ZSYTRF_RK or 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
!>                are stored on exit 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.
!>
!>          2) If WAY = 'R':
!>
!>          On entry, contains factorization details in format used in
!>          ZSYTRF_RK or 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
!>                are stored on exit 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, contains factorization details in format used in
!>          ZSYTRF_ROOK:
!>            a) all elements of the symmetric block diagonal
!>               matrix D on the diagonal of A and on superdiagonal
!>               (or subdiagonal) of A, and
!>            b) If UPLO = 'U': multipliers used to obtain factor U
!>               in the superdiagonal part of A.
!>               If UPLO = 'L': multipliers used to obtain factor L
!>               in the superdiagonal part of A.
!>
[in]LDA
!>          LDA is INTEGER
!>          The leading dimension of the array A.  LDA >= max(1,N).
!>
[in,out]E
!>          E is COMPLEX*16 array, dimension (N)
!>
!>          1) If WAY ='C':
!>
!>          On entry, just a workspace.
!>
!>          On exit, 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) is set to 0;
!>          If UPLO = 'L': E(i) = D(i+1,i), i=1:N-1, E(N) is set to 0.
!>
!>          2) If WAY = 'R':
!>
!>          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.
!>
!>          On exit, is not changed
!>
[in]IPIV
!>          IPIV is INTEGER array, dimension (N)
!>          On entry, details of the interchanges and the block
!>          structure of D as determined:
!>          1) by ZSYTRF_ROOK, if WAY ='C';
!>          2) by ZSYTRF_RK (or ZSYTRF_BK), if WAY ='R'.
!>          The IPIV format is the same for all these routines.
!>
!>          On exit, is not changed.
!>
[out]INFO
!>          INFO is INTEGER
!>          = 0:  successful exit
!>          < 0:  if INFO = -i, the i-th argument had an illegal value
!>
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
!>
!>