subroutine zsyconvf (UPLO, WAY, N, A, LDA, E, IPIV, INFO)
ZSYCONVF
ZSYCONVF
Purpose:
If parameter WAY = 'C': ZSYCONVF converts the factorization output format used in ZSYTRF 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. It also coverts in place details of the intechanges stored in IPIV from the format used in ZSYTRF into the format used in ZSYTRF_RK (or ZSYTRF_BK). If parameter WAY = 'R': ZSYCONVF 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 that is stored on exit in parameter A. It also coverts in place details of the intechanges stored in IPIV from the format used in ZSYTRF_RK (or ZSYTRF_BK) into the format used in ZSYTRF. ZSYCONVF can also convert in Hermitian matrix case, i.e. between formats used in ZHETRF and ZHETRF_RK (or ZHETRF_BK).
Parameters:
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
WAY
WAY is CHARACTER*1
= 'C': Convert
= 'R': Revert
N
N is INTEGER
The order of the matrix A. N >= 0.
A
A is COMPLEX*16 array, dimension (LDA,N)
1) If WAY ='C':
On entry, contains factorization details in format used in
ZSYTRF:
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:
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.
LDA
LDA is INTEGER
The leading dimension of the array A. LDA >= max(1,N).
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
IPIV
IPIV is INTEGER array, dimension (N)
1) If WAY ='C':
On entry, details of the interchanges and the block
structure of D in the format used in ZSYTRF.
On exit, details of the interchanges and the block
structure of D in the format used in ZSYTRF_RK
( or ZSYTRF_BK).
1) If WAY ='R':
On entry, details of the interchanges and the block
structure of D in the format used in ZSYTRF_RK
( or ZSYTRF_BK).
On exit, details of the interchanges and the block
structure of D in the format used in ZSYTRF.
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.
Date:
Contributors:
November 2017, Igor Kozachenko,
Computer Science Division,
University of California, Berkeley
Definition at line 211 of file zsyconvf.f.
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