Re: [R] formula for nls

2008-01-28 Thread Jarosław Jasiewicz
Christian Ritz pisze: > Hi Jarek, > > an alternative approach is to provide more precise starting values! > > It pays off to realise that it's possible to find quite good guesses > for some of the parameters in your model function: > > t ~ tr+(ts-tr)/((1+(a*h)^n)^(1-(1/n))) > > The par

Re: [R] formula for nls

2008-01-25 Thread Christian Ritz
Hi Jarek, an alternative approach is to provide more precise starting values! It pays off to realise that it's possible to find quite good guesses for some of the parameters in your model function: t ~ tr+(ts-tr)/((1+(a*h)^n)^(1-(1/n))) The parameters tr and ts correspond to the re

Re: [R] formula for nls

2008-01-23 Thread Gabor Grothendieck
On Jan 23, 2008 3:44 PM, Jarek Jasiewicz <[EMAIL PROTECTED]> wrote: > Gabor Grothendieck wrote: > > Try port algorithm. Please provide complete reproducible code and data > > when posting. > > > > > >> y <- 1/(x <- 1:5) > >> nls(y~k/x^n, start=list(k=1, n=1), algorithm = "port") > >> > > Nonlinear

Re: [R] formula for nls

2008-01-23 Thread Jarek Jasiewicz
Gabor Grothendieck wrote: > Try port algorithm. Please provide complete reproducible code and data > when posting. > > >> y <- 1/(x <- 1:5) >> nls(y~k/x^n, start=list(k=1, n=1), algorithm = "port") >> > Nonlinear regression model > model: y ~ k/x^n >data: parent.frame() > k n > 1 1

Re: [R] formula for nls

2008-01-23 Thread Gabor Grothendieck
Try port algorithm. Please provide complete reproducible code and data when posting. > y <- 1/(x <- 1:5) > nls(y~k/x^n, start=list(k=1, n=1), algorithm = "port") Nonlinear regression model model: y ~ k/x^n data: parent.frame() k n 1 1 residual sum-of-squares: 0 Algorithm "port", converge

[R] formula for nls

2008-01-23 Thread Jarek Jasiewicz
Hi! How to write in model's formula of type: nls(y~k/(x^n), data=data, start=list(k=1,n=1)) i.e the problem is on x^n, I(x^n) generate error thanks Jarek __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read