y ~ 1/(a + b*x^c) looks pretty good to me. If we assume a starting value of c=1 then we can get the starting values of a and b from lm(1/y ~ x) and then do an nls fit.
On 10/20/05, Xiaodong Jin <[EMAIL PROTECTED]> wrote: > How to obtain the FUNCTION for the following smooth curve? > x 0 100 250 500 1000 4000 > y 1.8 1.2 1.02 0.99 0.97 0.85 > > Thanks, > SJ > > > --------------------------------- > > [[alternative HTML version deleted]] > > ______________________________________________ > [email protected] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html > ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
