Philip Johnson: Can you be more precise on your target: simplex, marquardt, etc or something more general/basic? -- Jean-Philippe Vassilakis SOFIE Jobin-Yvon Horiba 7 Route d'Egly 91290 Arpajon France Tel: +33 (0)1 6490 9365 mailto:[log in to unmask] http://www.jobin-sofie.com