nls factor
On Wed, Apr 15, 2009 at 2:33 PM, Paul Smith <phhs80 at gmail.com> wrote:
On Wed, Apr 15, 2009 at 1:27 PM, Manuel Gutierrez <manuelgutierrezlopez at gmail.com> wrote:
I want to fit the model y=a*x^b using nls; where "a" should be different for each level of a factor. What is the easiest way to fit it? Can i do it with nls? I've looked the help pages and the MASS example in page 249 but the formula is different and I don't know how to specify it for my model.
What about linearizing the model with log() and use lm() afterwards?
Oops, sorry, I misread your post -- 'a' changes with the level of a factor. Paul