Try this. More info at http://ryacas.googlecode.com :
> library(Ryacas) > Asym <- Sym("Asym"); xmid <- Sym("xmid"); scal <- Sym("scal") > x <- Sym("x"); y <- Sym("y") > Solve(Asym/(1+exp((xmid-x)/scal))==y, x) expression(list(x == xmid - log(Asym/y - 1) * scal)) On Mon, Mar 29, 2010 at 7:24 AM, Kay Cichini <kay.cich...@uibk.ac.at> wrote: > > hello, > > is there a more convenient way to get the inverse of SSlogis than > transforming the function by hand? > > thanks, > kay > -- > View this message in context: > http://n4.nabble.com/inverse-function-of-SSlogis-tp1694995p1694995.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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.