On Tue, Apr 23, 2013 at 3:55 PM, J J <rnoob...@gmail.com> wrote: > Hello useRs (please don't kill me), > > I've fairly new to R having only a few months of playing around with R. > What little I've learned has been extremely useful. > > If someone could point me as to how to replicate the Boltzman Sigmodial > curve fit as provided by Graphpad software I'd be eternally grateful. > > Where we currently use Graphpad for only this one function,its seems > highly inefficient for a $100 piece of software to be used for only one > function (which isn't nearly as bad as the company's pandemic reliance on > Excel for nearly everything else). > > so anyway, what I'd normally do is take a set of data like this: > > pH counts 3.8 968 5.0 1347 5.8 2867 6.6 9203 7.0 15817 7.4 20297 8.2 > 31916 9.2 35756 > then fit this to a Boltzman sigmodial in Graphpad. Graphpad spits out a > much longer set of vectors and also information about v50 and confidence > intervals etc (if anyone is familiar with that software). This is what i'd > like to replicate. > > It might be that I just don't know what i'm doing,so feel free to call me > an idiot but any help is greatly appreciated!
Being unfamiliar with the problem domain, I'd imagine that nls() would probably be what you're looking for. Does ? nls seem promising? If so, we can help you get started. MW ______________________________________________ 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.
