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MC75 Sparse unsymmetric matrix: estimate condition number

This subroutine provides estimates of the classical condition number, ${\left|\right|A\left|\right|}_{\infty }{\left|\right|A^{-1}\left|\right|}_{\infty }$, and Skeel’s condition number, $\left|\right|\left|A^{-1}\right|\left|A\right||{|}_{\infty }$, of an $n\times n$ sparse matrix $A$. We denote by $\left|A\right|$ and $\left|A^{-1}\right|$ the matrices whose entries are the absolute values of the entries in $A$ and $A^{-1}$.