Re: eigs and Octave.app

[John W. Eaton]

On 12-Nov-2007, David Bateman wrote:

| Mark McClure wrote:
| >
| >  2) My impression is that eigs is unlikely to every be included
| >     in the standard Octave distribution due to license concerns
| >     involving ARPACK.  Is this correct?
| >
| > I ask the second question more for my students than for myself.
| > I'll be teaching a class in numerical linear algebra next
| > semester.  Our students have some access to Matlab on campus, but
| > I'd like to let them know about Octave as a viable alternative to
| > potentially save some of them some money and to expose them to
| > open source software.  Many of our applications of interest
| > involve eigensystems of large sparse matrices, however, so a
| > working eigs function is really essential.
| 
| Well, Sorensen isn't necessarily against a GPL distribution of ARPACK
| from what he said to me. However, he would be required to negotiate with
| Rice Universities Lawyers to allow this. The license terms of ARPACK
| allow full distribution in both source and binary form of ARPACK with
| Octave.

If this were true, then we would be distributing it.

| The restriction of ARPACK is trivial in that Rice University
| must be informed when ARPACK is used in a different project.

It may be trivial, but it is still an additional restriction not
allowed by the GPL, so as far as I can tell, it makes the ARPACK
license incompatible with the GPL.  The clause in question is

  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions
  are met:

    [...]

    Written notification is provided to the developers of intent to
    use this software.


The ARPACK authors may have said "we don't care", but the license
clearly states that redistribution requires written notification.
Since the GPL requires that *everyone* must be permitted to
redistribute the software without asking permission to do so, this
causes trouble.  It is also not clear what "use" means, so narrowly
it seems that this means that even someone who just wants to run the
software must provide written notification.

Also (as a separate issue) it is unfortunate that the ARPACK source
distribution (arpack96.tar.Z) doesn't even include a copy of the
license and the words copyright and license don't appear anywhere.

If the "written notification" clause were removed from the license,
then Octave could include an interface to ARPACK.  It would also be
nice if the arpack distribution itself included the license statement.

jwe