I would like to generate a natural spline where the slope beyond the last knot (the right outer knot) is constrained to be 0. Is that available in some package around? _____________________ Bendix Carstensen Senior Statistician Steno Diabetes Center Clinical Epidemiology Niels Steensens Vej 2-4 DK-2820 Gentofte Denmark phone: +45 30 75 87 38 bxc at steno.dk http://BendixCarstensen.com