[R] nls()

[J.M. Breiwick]

Hi,

I am using nls() with the form: nls(~my.fcn(...)) because I have to 
iteratively compute the expected y values. The function my.fcn() returns 
y.obs-y.pred

However, I want to fix some of the parameters in my.fcn at various values 
and compute the parameter estimates. In Splus there is such a thing as a 
parameterized dataframe. I don't think this exists in R so does anyone know 
how to set one or more of the parameters as constants in the model? Thank 
you.

Jeff Breiwick