curve fitting with given term

Ben Bolker · 2009-01-13T18:24:23Z

gregor rolshausen 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 som

Ben Bolker

Tue, Jan 13, 2009 10:24 AM

gregor rolshausen <gregor.rolshausen <at> biologie.uni-freiburg.de> writes:

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

Thread (4 messages)

gregor rolshausen curve fitting with given term Jan 13 Uwe Ligges curve fitting with given term Jan 13 gregor rolshausen curve fitting with given term Jan 13 Ben Bolker curve fitting with given term Jan 13