Re: [R] Fitting Weibull Model with Levenberg-Marquardt regression method

2010-08-23 Thread Gabor Grothendieck
On Mon, Aug 23, 2010 at 11:01 AM, Veronesi, Fabio wrote: > Hi, > I have a problem fitting the following Weibull Model to a set of data. > The model is this one: a-b*exp(-c*x^d) > If I fitted the model with CurveExpert I can find a very nice set of > coefficients which create a curve very close to

[R] Fitting Weibull Model with Levenberg-Marquardt regression method

2010-08-23 Thread Veronesi, Fabio
Hi, I have a problem fitting the following Weibull Model to a set of data. The model is this one: a-b*exp(-c*x^d) If I fitted the model with CurveExpert I can find a very nice set of coefficients which create a curve very close to my data, but when I use the nls.lm function in R I can't obtain th