gregor rolshausen <gregor.rolshausen <at> biologie.uni-freiburg.de> writes:
> > ok. sorry for being blurry. > > I have x,y data, that probably fits a asymptotic curve (asymptote at N). > now I want to fit a curve onto the data, that gives me the N. therefore > I thought to fit an e-function, namely N(1-e^(y/x)) onto the data and > get the N from the fitted curves' equation. > in the course of this, I was looking for a R-function to fit a given > function to data. > (I believe there is some implementation in MatLab for this kind of > question, anyhow, I wanted to look in R as well...) > > I am not an expert, so excuse my misuse of terms. I hope my problem > graspable...? > Perhaps you mean y = N*(1-exp(-x/a)) assuming x is the predictor and y the response variable. (This further assumes that the errors are independent, normally distributed [if you want to make inferences on the parameters etc.], etc..) Check out ?nls (for "nonlinear least squares"). good luck, Ben Bolker ______________________________________________ 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.