Anna Gretschel
2011-Aug-18 12:09 UTC
[R] what characteristics of model curve do parameters denote
Dear list, I'm trying to fit a chapman-richards equation to my data, only I cannot interpret the parameters a, b and d. I know that the parameter b denotes the asymptote, but for the others I couldn't figure out. But I do need to know this in order to set my starting values. Here's the model: modPoplar<- nls(Diameter ~ d*(1-exp(-b *Age))^a ,start=list(a=20,b=0.9,d=33)) I attached the graph, too. Hoping for your answers! Best, Anna -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Telefon: 01577-7805329 E-Mail: gretschel.anna at googlemail.com
Anna Lee
2011-Aug-18 12:25 UTC
[R] what characteristics of model curve do parameters denote
Dear list, I'm trying to fit a chapman-richards equation to my data, only I cannot interpret the parameters a, b and d. I know that the parameter b denotes the asymptote, but for the others I couldn't figure out. But I do need to know this in order to set my starting values. Here's the model: modPoplar<- nls(Diameter ~ d*(1-exp(-b *Age))^a ,start=list(a=20,b=0.9,d=33)) I attached the graph, too. Hoping for your answers! Best, Anna -- Der Inhalt dieser E-Mail ist vertraulich. Sollte Ihnen die E-Mail irrt?mlich zugesandt worden sein, bitte ich Sie, mich unverz?glich zu benachrichtigen und die E-Mail zu l?schen. This e-mail is confidential. If you have received it in error, please notify me immediately and delete it from your system.
Jeff Newmiller
2011-Aug-18 14:26 UTC
[R] what characteristics of model curve do parameters denote
Please refer to the posting guide... This is not a mathematics tutoring list. Your question does not appear to be about R, so no one has responded. --------------------------------------------------------------------------- Jeff Newmiller The ..... ..... Go Live... DCN:<jdnewmil@dcn.davis.ca.us> Basics: ##.#. ##.#. Live Go... Live: OO#.. Dead: OO#.. Playing Research Engineer (Solar/Batteries O.O#. #.O#. with /Software/Embedded Controllers) .OO#. .OO#. rocks...1k --------------------------------------------------------------------------- Sent from my phone. Please excuse my brevity. Anna Gretschel <gretschel.anna@googlemail.com> wrote: Dear list, I'm trying to fit a chapman-richards equation to my data, only I cannot interpret the parameters a, b and d. I know that the parameter b denotes the asymptote, but for the others I couldn't figure out. But I do need to know this in order to set my starting values. Here's the model: modPoplar<- nls(Diameter ~ d*(1-exp(-b *Age))^a ,start=list(a=20,b=0.9,d=33)) I attached the graph, too. Hoping for your answers! Best, Anna -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Telefon: 01577-7805329 E-Mail: gretschel.anna@googlemail.com _____________________________________________ 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]]