Version 2.4.0

2nd September 2016

Recent Changes

• Single
• Double
• Single Complex
• Double Complex

HSL_MA97 Sparse symmetric system using OpenMP

HSL_MA97 uses a direct method to solve large sparse symmetric linear systems of equations $AX=B$. This package optionally uses OpenMP and is designed to achieve bit-compatible results regardless of the number of threads used. It computes the sparse factorization

$A=PLD{\left(PL\right)}^{\star }\phantom{\rule{2em}{0ex}}\text{(Indeﬁnite)}$

or

$A=PL{L}^{\star }{P}^{T}\phantom{\rule{2em}{0ex}}\text{(Positive-deﬁnite)}$

where ${L}^{\star }={L}^{T}$ (real symmetric or complex symmetric) or ${L}^{\star }={L}^{H}$ (complex Hermitian, where ${L}^{H}$ denotes the conjugate transpose of $L$), $P$ is a permutation matrix, $L$ is lower triangular, and $D$ is block diagonal with blocks of size $1×1$ and $2×2$.

If $A$ is large, bit-compatible answers are not required, we recommend using HSL_MA86 or HSL_MA87 instead for better eﬃciency.

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