Fortran 77 subroutines for solving large scale eigenvalue problems
Description
ARPACK is a collection of Fortran 77 subroutines designed to solve large scale eigenvalue problems.
The package is designed to compute a few eigenvalues and corresponding eigenvectors of a general n
by n matrix A. It is most appropriate for large sparse or structured matrices A where structured
means that a matrix-vector product w <- Av requires order n rather than the usual order n**2
floating point operations. This software is based upon an algorithmic variant of the Arnoldi process
called the Implicitly Restarted Arnoldi Method (IRAM).