Odyssee index page

The Odyssée Tool

Odyssée is an automatic differentiation tool developed in SAFIR at INRIA - Sophia Antipolis and University of Nice Sophia Antipolis (UNSA) in Objective Caml that belongs to the Caml familly.

For Odyssée (see publications), a program is a set of Fortran-77 units (functions or subroutines), whose call-graph forms a tree. The root of the tree is called the head-unit. It is able to ``differentiate a program'', with respect to the input variables (arguments and/or common variables) of the head-unit. The result of the differentiation of a program from its head-unit with respect to a set of active inputs is a new program, which can compute at arbitrary points the derivative of the function evaluated in the original program.

Odyssée can differentiate a program as a whole, detecting active variables, those whose value depends on the variables with respect to which the function is differentiated. Both the direct and reverse modes of differentiation are implemented. The first one is appropriate for computing directional derivatives, the second is adapted to the efficient computation of gradients.

Odyssée generates :
In Direct Mode, the tangent linear application which is the Jacobian matrix times a vector.
In Reverse Mode, the cotangent linear application which is the transposed Jacobian matrix times a vector in the dual space.

How to get and install Odyssée

Odyssée is available free of charge for research, education or internal evaluation. In exchange of Odyssée you are asked to send us your comments on Odyssée and references of papers or reports you write that deal with Odyssée. It will help us know more about applications of Odyssee and also fill our bibliography page.

© Copyright Notice

       1997 University of Nice Sophia Antipolis 
       1997 Institut National de Recherche en Informatique et en Automatique

The source code of Odyssée is distributed ftp://ftp-sop.inria.fr/tropics/odyssee

If you have got any problem installing or using Odyssée, you acn contact Odyssée team at odyssee@sophia.inria.fr.

Odyssée and the rest of the World

Odyssée has been developped and applied within industrial collaborations with Elf, CNES, DASSAULT, ESSILOR, EDF, Alenia.

Present works on Odyssée are performed within different kinds of collaborations :

It is used at various places by academics or industries.

All Automatic Differentiation Tools

A Compilation of Automatic Differentiation Tools has been Presented at the 1995 International Conference on Industrial and Applied Mathematics in Hamburg.

Here is a list of some new tools : FADBAD and TADIFF, HSL, ADMAT (ADMIT), MIPAD.

Christele Faure , last update on May 1999