LAPACK

Category: Libraries-Math-LinearAlgebra

Description

An optimized version of LAPACK is provided by Cray in SciLib (-lsci) and will be linked against automatically by the Cray wrappers cc, CC, and ftn. NICS also provides a reference LAPACK compiled with -O3 -g. This will likely be useful when troubleshooting code, for example.

LAPACK is written in Fortran77 and provides routines for solving systems of simultaneous linear equations, least-squares solutions of linear systems of equations, eigenvalue problems, and singular value problems. The associated matrix factorizations (LU, Cholesky, QR, SVD, Schur, generalized Schur) are also provided, as are related computations such as reordering of the Schur factorizations and estimating condition numbers. Dense and banded matrices are handled, but not general sparse matrices. In all areas, similar functionality is provided for real and complex matrices, in both single and double precision.

LAPACK routines are written so that as much as possible of the computation is performed by calls to the Basic Linear Algebra Subprograms (BLAS). While LINPACK and EISPACK are based on the vector operation kernels of the Level 1 BLAS, LAPACK was designed at the outset to exploit the Level 3 BLAS -- a set of specifications for Fortran subprograms that do various types of matrix multiplication and the solution of triangular systems with multiple right-hand sides. Because of the coarse granularity of the Level 3 BLAS operations, their use promotes high efficiency on many high-performance computers, particularly if specially coded implementations are provided by the manufacturer.

Use

To get the Cray optimized LAPACK, use libsci (-lsci), and the Cray wrappers cc, CC, and ftn will automatically link against libsci. You can also load the acml module if you wish to use that instead, which is useful when invoking the PGI, Pathscale, or GNU compilers directly. As a third option, we are providing a reference LAPACK. There are online man pages for each LAPACK function.

  module avail lapack
  module load lapack/3.1.1-ref
  ftn test.f90   OR   pgf90/pathf90/gfortran test.f90 ${LAPACK_LIB}

Support

This package has the following support level : Supported

Available Versions

Version Available Builds
pgi pathscale gnu Other
3.0 vendor
3.1.1
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