search for: otolith

I'm tyring to fit a relatively simple nls model to some data, but keep coming up against the same error (code follows): Oto=nls(Otolith ~ Linf*(1-exp(-k(AGE-to))), data = ages, start = list(Linf=1000, k=0.1, to=0.1), trace = TRUE) The error message I keep getting is "Error in eval(expr, envir, enclos) : could not find function "k"". I've used this line of code for other nls models (with dif...

...fax/téléc: 902-426-1506 Bedford Institute of Oceanography 1 Challenger Drive P.O. Box 1006 Dartmouth, Nova Scotia Canada, B2Y 4A2 Institut Océanographique de Bedford 1, promenade Challenger C.P. 1006 Dartmouth, Nouvelle-Écosse Canada, B2Y 4A2 Shark Website http://marinebiodiversity.ca/shark/ Otolith Website http://marinebiodiversity.ca/otolith/ Skate Website http://www.marinebiodiversity.ca/skatesandrays/index.htm [[alternative HTML version deleted]]

Hi, I have a dataset like this, > testdata Grouped Data: expr ~ visit | subject expr visit subject 1 6.502782 V1 A 2 6.354506 V1 B 3 6.349184 V1 C 4 6.386301 V2 A 5 6.376405 V2 B 6 6.758640 V2 C 7 6.414142 V3 A 8 6.354521 V3 B 9 6.396636 V3 C I tried the command >