Skip to content

searching for an analytical function

2 messages · Casiano Rodriguez Leon, Spencer Graves

#
Hello all,

This is the problem I am dealing with:

I have an R data frame with the sample of observations of the control
variables "x1", "x2" , ... and the response variable "y".
I also have a set of "base" functions = "x1, "x2", ..., "log(x1)",
"log(x2)", ...

What I need is to have the ANALYTICAL function, i.e. a polynom of the
given base functions, (s.t like x1^3*log(x2) ) that represents my data,
i.e. that minimizes the average errors of the predictions.

I guess that using non-parametric regression I can obtain a non analytical
answer. Do you know of any solutions for that problem or similars?  If so,
where can I find them?

Many, many thanks,

Casiano
#
Have you considered stepwise regression, e.g., stepAIC from the MASS 
library or stepAIC.c dowloadable from "www.prodsyse.com"?  The latter is 
not solidly debugged but has worked with several examples with "lm".  If 
you have the time, you can dig through the code and modify the hierarchy 
rules to suit your needs.

hope this helps.  spencer graves
Casiano Rodriguez Leon wrote: