LAPACK provides routines for solving systems of simultaneous linear
equations, least-squares solutions of linear systems of equations,
eigenvalue problems, and singular value problems.

Install an optimized BLAS instead of the reference BLAS from Netlib if you
wish to improve LAPACK's performance. Otherwise, use the BLAS build script 
provided at Slackbuilds.org.  You may also build your own tuned lapack library
with ATLAS.

This requires blas.