Hi Gabriela, as suggested by Jim I'll have a look as soon as possible (but only tomorrow I'm afraid). Maybe you could provide me with a dataset of yours which shows the problem (use direct postin gt o my own address olivier.eterradossi at ema.fr, instead of posting the data to Rlist) ? Thanks, Olivier
Olivier ETERRADOSSI Ma?tre-Assistant CMGD / Equipe "Propri?t?s Psycho-Sensorielles des Mat?riaux" Ecole des Mines d'Al?s H?lioparc, 2 av. P. Angot, F-64053 PAU CEDEX 9 tel std: +33 (0)5.59.30.54.25 tel direct: +33 (0)5.59.30.90.35 fax: +33 (0)5.59.30.63.68 http://www.ema.fr