Thanks everyone for al your help, I don't think it's necessarily as easy as I first thought.
I'm going to have a think about it and try some things out. And I'll be back if I get stuck! Thanks very much, Frances On 4 April 2014 09:11, Keith Jewell <keith.jew...@campdenbri.co.uk> wrote: > On 03/04/2014 16:26, Frances Cheesman wrote: > >> Hi all, >> >> I have a number of bacterial growth curves I would like to find the >> equations for these and then integrate them to find the area under the >> curves for me to do stats on later. >> >> Is there any way I can do this in R? >> >> Thanks, >> >> Frances >> >> [[alternative HTML version deleted]] >> >> Responding to the curve fitting question and passing over the > integration issue... > > It is quite common to use nls to fit equations to log(count) v time data. > You'll have to choose an appropriate model, ideally as a self starting nls > model. Of those included in the stats package you might consider SSfpl, > SSgompertz, SSlogis and SSweibull. > > But choice of a model is really a microbiological issue and all those > models might be considered a little passe. Fitting this kind of sigmoidal > model can be difficult unless the data is good. > > > ______________________________________________ > 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. > [[alternative HTML version deleted]] ______________________________________________ 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.
