Howdee,
My question appears at #6 below:
1. I want to model the growth of each of a large number of individuals using
a 4-parameter logistic growth curve.
2. nlme does not converge with the random structure that I want to use.
3. nlsList does not converge for some individuals.
4. I decided to go around nlsList using:
t(sapply(split(data, list(data$id)),
function(subd){coef(nls(mass ~ SSfpl(age, A, B, xmid, scal), data subd))}))
5. This does not converge either:
'Error in nls(y ~ cbind(1, 1/(1 + exp((xmid - x)/exp(lscal)))), data = xy,
:
singular gradient'
6. Would anyone know if I can get R to skip non-converging use of nls() so
that I can at least obtain the parameters for the curves which R can fit?
Thanks for your time,
Marc
==================Marc B?lisle
Professeur adjoint
Chaire de recherche du Canada en ?cologie spatiale et en ?cologie du paysage
D?partement de biologie
Universit? de Sherbrooke
2500 Boul. de l'Universit?
Sherbrooke, Qu?bec
J1K 2R1 Canada
T?l: +1-819-821-8000 poste 61313
Fax: +1-819-821-8049
Courri?l: Marc.M.Belisle at USherbrooke.ca
Hi Marc, use try() Cheers Andrew On Mon, Feb 18, 2008 at 01:45:35PM -0500, Marc Belisle wrote:> Howdee, > > My question appears at #6 below: > > 1. I want to model the growth of each of a large number of individuals using > a 4-parameter logistic growth curve. > > 2. nlme does not converge with the random structure that I want to use. > > 3. nlsList does not converge for some individuals. > > 4. I decided to go around nlsList using: > > t(sapply(split(data, list(data$id)), > function(subd){coef(nls(mass ~ SSfpl(age, A, B, xmid, scal), data > subd))})) > > 5. This does not converge either: > > 'Error in nls(y ~ cbind(1, 1/(1 + exp((xmid - x)/exp(lscal)))), data = xy, > : > singular gradient' > > 6. Would anyone know if I can get R to skip non-converging use of nls() so > that I can at least obtain the parameters for the curves which R can fit? > > Thanks for your time, > > Marc > > ==================> Marc B?lisle > Professeur adjoint > Chaire de recherche du Canada en ?cologie spatiale et en ?cologie du paysage > D?partement de biologie > Universit? de Sherbrooke > 2500 Boul. de l'Universit? > Sherbrooke, Qu?bec > J1K 2R1 Canada > > T?l: +1-819-821-8000 poste 61313 > Fax: +1-819-821-8049 > Courri?l: Marc.M.Belisle at USherbrooke.ca > > ______________________________________________ > R-help at 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. > > -- > This message has been scanned for viruses and > dangerous content by MailScanner, and is > believed to be clean.-- Andrew Robinson Department of Mathematics and Statistics Tel: +61-3-8344-6410 University of Melbourne, VIC 3010 Australia Fax: +61-3-8344-4599 http://www.ms.unimelb.edu.au/~andrewpr http://blogs.mbs.edu/fishing-in-the-bay/
See warnOnly in ?nls.control On Feb 18, 2008 1:45 PM, Marc Belisle <marc.m.belisle at usherbrooke.ca> wrote:> Howdee, > > My question appears at #6 below: > > 1. I want to model the growth of each of a large number of individuals using > a 4-parameter logistic growth curve. > > 2. nlme does not converge with the random structure that I want to use. > > 3. nlsList does not converge for some individuals. > > 4. I decided to go around nlsList using: > > t(sapply(split(data, list(data$id)), > function(subd){coef(nls(mass ~ SSfpl(age, A, B, xmid, scal), data > subd))})) > > 5. This does not converge either: > > 'Error in nls(y ~ cbind(1, 1/(1 + exp((xmid - x)/exp(lscal)))), data = xy, > : > singular gradient' > > 6. Would anyone know if I can get R to skip non-converging use of nls() so > that I can at least obtain the parameters for the curves which R can fit? > > Thanks for your time, > > Marc > > ==================> Marc B?lisle > Professeur adjoint > Chaire de recherche du Canada en ?cologie spatiale et en ?cologie du paysage > D?partement de biologie > Universit? de Sherbrooke > 2500 Boul. de l'Universit? > Sherbrooke, Qu?bec > J1K 2R1 Canada > > T?l: +1-819-821-8000 poste 61313 > Fax: +1-819-821-8049 > Courri?l: Marc.M.Belisle at USherbrooke.ca > > ______________________________________________ > R-help at 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. >