Hi Rolf and Others, Thanks Rolf for your suggestion. I've had a look at segmented, but can't see how it can help.
My model is the solution to an ODE of a physical system. The fitted parameters from this model are the answers I require. I'm not sure how segmented can help -- it is a linear regression tool. Can you let me know how it could be used? Thanks, Matt Redding >-----Original Message----- >From: Rolf Turner [mailto:rolf.tur...@xtra.co.nz] >Sent: Thursday, 13 October 2011 6:46 PM >To: Redding, Matthew >Cc: r-help@r-project.org >Subject: Re: [R] nls: singular convergeance > >On 13/10/11 21:26, Redding, Matthew wrote: >> Hi Rolf and others >> >> Will this make any difference to the convergence? > I have no idea, really. I don't know if convergence issues even > arise in the context of the "segmented" package. I have never > encountered any. > > Try it and see. Shouldn't take more than about 10 >minutes, all up. > > cheers, > > Rolf >> ----- Original Message ----- >> From: Rolf Turner<rolf.tur...@xtra.co.nz> >> To: Redding, Matthew >> Cc: r-help@r-project.org<r-help@r-project.org> >> Sent: Thu Oct 13 18:04:53 2011 >> Subject: Re: [R] nls: singular convergeance >> >> On 13/10/11 18:02, Redding, Matthew wrote: >>> Dear R-experts, >>> >>> I have 28 data points that I would like to fit with a non linear >>> broken-stick -- with three fitted parameters. >>> When I view trace -- and use the final values as lines on the graph >>> of data -- it looks pretty good. >>> >>> Q1. Why am I getting singular convergeance? >>> Q2. Can you suggest another approach that may prove more satisfying? >> <SNIP> >> >> Have you thought of using the "segmented" package instead of rolling >> your own with nls? >> >> cheers, >> >> Rolf Turner > > We're behind the Bid! GOLD COAST 2018 - XXI COMMONWEALTH GAMES CANDIDATE CITY www.goldcoast2018bid.com ********************************DISCLAIMER**************************** The information contained in the above e-mail message or messages (which includes any attachments) is confidential and may be legally privileged. It is intended only for the use of the person or entity to which it is addressed. If you are not the addressee any form of disclosure, copying, modification, distribution or any action taken or omitted in reliance on the information is unauthorised. Opinions contained in the message(s) do not necessarily reflect the opinions of the Queensland Government and its authorities. If you received this communication in error, please notify the sender immediately and delete it from your computer system network. ______________________________________________ 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.
