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Purpose


LA_SYSV computes the solution to a linear system of equations $ A\,X = B $, where $A$ is a real or complex symmetric matrix and $X$ and $B$ are rectangular matrices or vectors. A diagonal pivoting method is used to factor $A$ as

\begin{displaymath}A = U\, D\, U^T \mbox{ if {\bf UPLO} = 'U', or }
A = L\,D\,L^T \mbox{ if {\bf UPLO} = 'L'} \end{displaymath}

where $U$ (or $L$) is a product of permutation and unit upper (or lower) triangular matrices, and $D$ is a symmetric block diagonal matrix with $1 \times 1$ and $2 \times 2$ diagonal blocks. The factored form of $A$ is then used to solve the above system.
LA_HESV computes the solution to a linear system of equations $ A\,X = B $, where $A$ is a complex Hermitian matrix and $X$ and $B$ are rectangular matrices or vectors. A diagonal pivoting method is used to factor $A$ as

\begin{displaymath}A = U\, D\, U^H \mbox{ if {\bf UPLO} = 'U', or }
A = L\, D\, L^H \mbox{ if {\bf UPLO} = 'L'}\end{displaymath}

where $U$ (or $L$) is a product of permutation and unit upper (or lower) triangular matrices, and $D$ is a complex Hermitian block diagonal matrix with $1 \times 1$ and $2 \times 2$ diagonal blocks. The factored form of $A$ is then used to solve the above system.



next up previous contents index
Next: Arguments Up: Symmetric Indefinite Linear Systems Previous: LA_SYSV / LA_HESV   Contents   Index
Susan Blackford 2001-08-19