# Arpack.jl

This package provides bindings to ARPACK, which can be used to perform iterative solutions for eigensystems (using `eigs`

) or singular value decompositions (using `svds`

).

**Notes**

The ARPACK Fortran library is not re-entrant.

`Arpack.jl`

should only be used from one thread in a Julia program.ARPACK uses a random starting vector by default. This causes the phase of the singular vectors to be random (or just the sign, for real values).