ARPACK-NG is a collection of Fortran77 subroutines designed to solve large scale
eigenvalue problems.

Important Features:

* Reverse Communication Interface.
* Single and Double Precision Real Arithmetic Versions for Symmetric,
  Non-symmetric, Standard or Generalized Problems.
* Single and Double Precision Complex Arithmetic Versions for Standard or
  Generalized Problems.
* Routines for Banded Matrices - Standard or Generalized Problems.
* Routines for The Singular Value Decomposition.
* Example driver routines that may be used as templates to implement numerous
  Shift-Invert strategies for all problem types, data types and precision.

This project is a joint project between Debian, Octave and Scilab in order to
provide a common and maintained version of arpack.

Indeed, no single release has been published by Rice university for the last
few years and since many software (Octave, Scilab, R, Matlab...) forked it and
implemented their own modifications, arpack-ng aims to tackle this by providing
a common repository and maintained versions.

arpack-ng is replacing arpack in Debian & Ubuntu. Fink, Fedora and Redhat are
currently doing the same move.


1. You have successfully unbundled ARPACK-NG and are now in the ARPACK-NG
   directory that was created for you.

2. 
   The directory SRC contains the top level routines including 
   the highest level reverse communication interface routines

      ssaupd, dsaupd - symmetric single and double precision
      snaupd, dnaupd - non-symmetric single and double precision
      cnaupd, znaupd - complex non-symmetric single and double precision

   The headers of these routines contain full documentation of calling
   sequence and usage.  Additional information is in the DOCUMENTS directory.

   The directory PARPACK contains the Parallel ARPACK routines.
     

3. Example driver programs that illustrate all the computational modes,
   data types and precisions may be found in the EXAMPLES directory.
   Upon executing the 'ls EXAMPLES' command you should see

      BAND
      COMPLEX
      NONSYM
      README
      SIMPLE
      SVD
      SYM

   Example programs for banded, complex, nonsymmetric, symmetric,
   and singular value decomposition may be found in the directories
   BAND, COMPLEX, NONSYM, SYM, SVD respectively.  Look at the README
   file for further information.  To get started, get into the SIMPLE
   directory to see example programs that illustrate the use of ARPACK in
   the simplest modes of operation for the most commonly posed 
   standard eigenvalue problems.  


   Example programs for Parallel ARPACK may be found in the directory
   PARPACK/EXAMPLES. Look at the README file for further information.

   The following instructions explain how to make the ARPACK library.

4. Unlike ARPACK, ARPACK-NG is providing autotools based build system.
   Therefor, the classical:
   $ ./configure
   $ make 
   $ make install
   should work as expected.

5. Within DOCUMENTS directory there are three files 

   ex-sym.doc 
   ex-nonsym.doc and
   ex-complex.doc

   for templates on how to invoke the computational modes of ARPACK.
   Also look in the README file for explanations concerning the 
   other documents.


   Danny Sorensen   at  sorensen@caam.rice.edu
   Richard Lehoucq  at  rblehou@sandia.gov
   Chao Yang        at  cyang@lbl.gov
   Kristi Maschhoff at  kristyn@tera.com
   Sylvestre Ledru  at  sylvestre.ledru@scilab-enterprises.com
   Allan Cornet     at  allan.cornet@scilab.org

 Good luck and enjoy.

