-
template<typename T>
void syconvf(char *uplo, char *way, integer *n, T *a, integer *lda, T *e, integer *ipiv, integer *info)# SYCONVF converts the factorization output format.
Purpose:
If parameter WAY = 'C': SYCONVF converts the factorization output format used in SYTRF provided on entry in parameter A into the factorization output format used in SYTRF_RK (or SYTRF_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 SYTRF into the format used in SYTRF_RK (or SYTRF_BK). If parameter WAY = 'R': SYCONVF performs the conversion in reverse direction, i.e. converts the factorization output format used in SYTRF_RK (or SYTRF_BK) provided on entry in parameters A and E into the factorization output format used in SSYTRF 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 SYTRF_RK (or SYTRF_BK) into the format used in SYTRF.
- Parameters:
UPLO – [in]
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 – [in]
WAY is CHARACTER*1
= ‘C’: Convert
= ‘R’: RevertN – [in]
N is INTEGER
The order of the matrix A. N >= 0.
A – [inout]
A is REAL array, dimension (LDA,N)
1) If WAY =’C’:
On entry, contains factorization details in format used in SSYTRF:
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 SSYTRF_RK or 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 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 SSYTRF_RK or 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 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 SSYTRF:
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 – [in]
LDA is INTEGER
The leading dimension of the array A. LDA >= fla_max(1,N).
E – [inout]
E is REAL 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 changedIPIV – [inout]
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 SSYTRF.
On exit, details of the interchanges and the block structure of D in the format used in SSYTRF_RK (or SSYTRF_BK).
1) If WAY =’R’:
On entry, details of the interchanges and the block structure of D in the format used in SSYTRF_RK (or SSYTRF_BK).
On exit, details of the interchanges and the block structure of D in the format used in SSYTRF.INFO – [out]
INFO is INTEGER
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value