On 16-12-2013, at 08:52, 水静流深 <1248283...@qq.com> wrote: > input <- " > t y > 1 5.3 > 2 7.2 > 3 9.6 > 4 12.9 > 5 17.1 > 6 23.2" > dat<-read.table(textConnection(input),header=TRUE,sep="") > t<-dat[,1] > y<-dat[,2] > > `y=3.975*(1.341^t)` is the resule of fit,how can i use `nls` function to get > it?
Have you looked at ?nls. Have you simply tried nls(y~a*b^t,data=dat) You can also do a linear regression on log(y) ~ A + B* t. And afterwards transform to the original coefficients. Berend > [[alternative HTML version deleted]] > Please do not post in html. > ______________________________________________ > 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.
