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LAPACK 3.11.0
LAPACK: Linear Algebra PACKage
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LAPACK 3.11.0
LAPACK: Linear Algebra PACKage
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| subroutine dsyt01_3 | ( | character | UPLO, |
| integer | N, | ||
| double precision, dimension( lda, * ) | A, | ||
| integer | LDA, | ||
| double precision, dimension( ldafac, * ) | AFAC, | ||
| integer | LDAFAC, | ||
| double precision, dimension( * ) | E, | ||
| integer, dimension( * ) | IPIV, | ||
| double precision, dimension( ldc, * ) | C, | ||
| integer | LDC, | ||
| double precision, dimension( * ) | RWORK, | ||
| double precision | RESID | ||
| ) |
DSYT01_3
DSYT01_3 reconstructs a symmetric indefinite matrix A from its
block L*D*L' or U*D*U' factorization computed by DSYTRF_RK
(or DSYTRF_BK) and computes the residual
norm( C - A ) / ( N * norm(A) * EPS ),
where C is the reconstructed matrix and EPS is the machine epsilon. | [in] | UPLO | UPLO is CHARACTER*1
Specifies whether the upper or lower triangular part of the
symmetric matrix A is stored:
= 'U': Upper triangular
= 'L': Lower triangular |
| [in] | N | N is INTEGER
The number of rows and columns of the matrix A. N >= 0. |
| [in] | A | A is DOUBLE PRECISION array, dimension (LDA,N)
The original symmetric matrix A. |
| [in] | LDA | LDA is INTEGER
The leading dimension of the array A. LDA >= max(1,N) |
| [in] | AFAC | AFAC is DOUBLE PRECISION array, dimension (LDAFAC,N)
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. |
| [in] | LDAFAC | LDAFAC is INTEGER
The leading dimension of the array AFAC.
LDAFAC >= max(1,N). |
| [in] | E | 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. |
| [in] | IPIV | IPIV is INTEGER array, dimension (N)
The pivot indices from DSYTRF_RK (or DSYTRF_BK). |
| [out] | C | C is DOUBLE PRECISION array, dimension (LDC,N) |
| [in] | LDC | LDC is INTEGER
The leading dimension of the array C. LDC >= max(1,N). |
| [out] | RWORK | RWORK is DOUBLE PRECISION array, dimension (N) |
| [out] | RESID | RESID is DOUBLE PRECISION
If UPLO = 'L', norm(L*D*L' - A) / ( N * norm(A) * EPS )
If UPLO = 'U', norm(U*D*U' - A) / ( N * norm(A) * EPS ) |
1.9.4