[R] Substitute initial guesses of parameters in a function

[philippe massicotte]

Thank you!


> Date: Wed, 3 Dec 2014 08:02:17 -0500
> From: murdoch.duncan at gmail.com
> To: pmassicotte at hotmail.com; r-help at r-project.org
> Subject: Re: [R] Substitute initial guesses of parameters in a function
> 
> On 03/12/2014 7:37 AM, philippe massicotte wrote:
> > Hi everyone, I have a formula like this:
> >
> > f <- as.formula(y ~ p0a * exp(-0.5 * ((x - p1a)/p2a)^2))
> >
> > I would like to "dynamically" provide starting values for p0a, p1a, p2a. Is there a way to do it?
> 
> Just give a named vector of starting values.
> >
> > #Params estimates
> > p <- c(12, 10, 1)
> 
> Should be p <- c(p0a = 12, p1a = 10, p2a = 1)
> >
> > # This is where I have difficulties
> > mystart <- substitute(...)
> >
> > nls(formula = f, start = mystart)
> 
> Now start = p will work.  No need to mess with substitute.  (And no need 
> to use as.formula on the very first line; that's already a formula.)
> 
> Duncan Murdoch
> >
> > Regards,
> > Philippe
> >   		 	   		
> > 	[[alternative HTML version deleted]]
> >
> > ______________________________________________
> > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> > 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]]