[R] nls()

[Spencer Graves]

	  I have passed the identities and values of fixed parameters via the 
"..." arguments in optim;  I don't know about nls.  Then internal to the 
function that optim is to minimize, I combine the "x" argument with the 
fixed parameters to obtain the full set of parameters.  I've used that 
effectively.  It's not trivial, but it can be made to work.

	  spencer graves

J.M. Breiwick wrote:

> 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
> 
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Spencer Graves, PhD
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