deltaquattro wrote:
> Hi,

Hi.

> I'm a Fortran scientific programmer,

Me too, although not so much anymore.  Ruby's ruined it for me.  :)

> and recently I have had to write
> a lot of shell scripts which let different codes communicate by means
> of I/O files. Right now I'm using awk and (to a lesser extent) perl to
> do this.

Sounds like me in 1999.

> However, I'd like to learn a newer scripting language and at
> the same time learn OOP, so I'm choosing between Python and Ruby.

That was we did underneath our Exploring XP for Scientific Research
IEEE article: ieeexplore.ieee.org/iel5/52/26915/01196317.pdf

> 1) (easy) automatic I/O files manipulation. Calculations, comparisons,
> etc. among values contained in tables, and correspondent modfication
> of the table entries;

All the time; just cooked another one up a couple hours ago to check input
parameter distributions for a Monte Carlos sensitivity analysis of
flowfield radiation of a capsule re-entering Earth at 10.5 km/s.

> 2) (less easy) semi-automatic generation of graph, images, report,
> etc., based on data in huge binary files (O(Gb));

I've done at least 4 scientific papers with Ruby generated graphs,
images, reports, and tables based on data in huge binary files.
I've helped several other colleagues do the same.

> 3) (hard) create GUIs for scientifc codes, which could enable
> unexperienced users to run the codes;

I'm embarking on this journey by wrapping simulation codes
in a RESTful web service, currently with Rails.  So one gains
both a "GUI" via a web browser, but there is also a RESTful back
door to enable one to glue together simulation tools from
disparate disciplines.

> Which are the main differences between Ruby and Python?

Ruby derives power from diversity;  Python derives power from
the one true way.  My brain best fit the former; YMMV.

I feel that creating a domain specific language is easier
in Ruby than Python, but my Python skills are /extremely/ weak.

> Which is easier to learn?

Yes.

> I've seen a lot of numerical libraries/extensions for
> Python: does Ruby also support scientific programming?

Yes; see for instance http://sciruby.codeforpeople.com

Regards,
--
Bil Kleb
http://fun3d.larc.nasa.gov
http://nasarb.rubyforge.org