It appears that as one proceeds from right to left that it flattens out at 0.021 so lets try this where we have added a bit to 0.021 to avoid log(0)
plot(x, log(0.0211 - y)) and plot(1/x, log(0.0211 - y)) Except for the first point the latter plot looks linear so lets try: fm <- nls(y ~ cbind(1, exp(- a / x)), start = c(a = mean(x)), alg = "plinear") fm plot(x, y) lines(x, fitted(fm)) which seems to fit fairly well. On Fri, May 14, 2010 at 6:36 AM, Dani Valverde <daniel.valve...@uab.cat> wrote: > Hello, > It is a very naive question, but here it is. I have this values: > > x: 0.5 4 6 8 12 > > y: 0.021 0.021 0.020 0.018 0.012 > > I need to fit a function to them. How can I do it with R? > Thank you so much! > > Dani > > -- > Daniel Valverde Saubí > > Grup de Biologia Molecular de Llevats > Facultat de Veterinària de la Universitat Autònoma de Barcelona > Edifici V, Campus UAB > 08193 Cerdanyola del Vallès- SPAIN > > Tlf. +34 93 581 1910 > Fax: +34 93 581 1573 > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
