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As mentioned before, **LAPACK**, or Linear Algebra PACKage
[3], is a collection of routines for solving linear
systems, least squares problems, eigenproblems, and singular problems.
High performance is attained by using algorithms that do most
of their work in calls to the BLAS, with an emphasis on matrix-matrix
multiplication. Each routine has one or more *performance
tuning parameters*, such as the sizes of the blocks operated
on by the BLAS. These parameters are machine dependent and
are obtained from a table defined when the package is installed
and referenced at runtime.
The LAPACK routines are written as a single thread of execution. LAPACK can
accommodate shared-memory machines, provided parallel BLAS are
available (in other words, the only parallelism is implicit in calls
to BLAS). Extensive performance results for LAPACK can be found in
the LAPACK Users' Guide [3].

*Susan Blackford *

Tue May 13 09:21:01 EDT 1997