Re: [R] nls function error

2013-10-27 Thread Rolf Turner
On 10/28/13 00:10, Hansol Yu wrote: data(Boston, package='MASS') y <- Boston$nox x <- Boston$dis nls(y~ A + B * exp(C * x), start=list(A=1, B=1, C=1)) Error in nls(y ~ A + B * exp(C * x), start = list(A = 1, B = 1, C = 1), : step factor 0.000488281 reduced below 'minFactor' of 0.000976562 I

Re: [R] nls function

2012-04-11 Thread peter dalgaard
On Apr 11, 2012, at 16:51 , John C Nash wrote: > nls() often gives this message, which is misleading in that it is the > Jacobian that is not > of full rank in the solution of J * delta ~ - residuals or in more > conventional > Gauss-Newton J' * J delta = -g = - J' * residuals. My view is

Re: [R] nls function

2012-04-11 Thread John C Nash
nls() often gives this message, which is misleading in that it is the Jacobian that is not of full rank in the solution of J * delta ~ - residuals or in more conventional Gauss-Newton J' * J delta = -g = - J' * residuals. My view is that the gradient itself cannot be "singular". It's just

Re: [R] nls function

2012-04-10 Thread peter dalgaard
On Apr 10, 2012, at 22:03 , nerak13 wrote: > Hi, > > I've got the following data: > > x<-c(1,3,5,7) > y<-c(37.98,11.68,3.65,3.93) > penetrationks28<-dataframe(x=x,y=y) > > now I need to fit a non linear function so I did: > > fit <- nls(y ~ I(a+b*exp(1)^(-c * x)), data = penetrationks28, star

Re: [R] nls function

2012-04-10 Thread David Winsemius
On Apr 10, 2012, at 4:03 PM, nerak13 wrote: Hi, I've got the following data: x<-c(1,3,5,7) y<-c(37.98,11.68,3.65,3.93) penetrationks28<-dataframe(x=x,y=y) now I need to fit a non linear function so I did: fit <- nls(y ~ I(a+b*exp(1)^(-c * x)), data = penetrationks28, start = list(a=0,b = 1,