How to generate PMML for stepwise polynomial regression

Question

I have tried using R and it throws below error. How to generate PMML for stepwise polynomial regression ?

Code snippet:

library(reshape2)

library(pmml)

data(tips)

fit <- lm(total_bill ~ poly(tip, 1, raw=TRUE),data = tips)

pmmlFile<-pmml(fit,data=tips)


 

Error:

Error in .pmmlDataDictionary(field, weights = weights, transformed = transforms) : nmatrix.2 class is not supported for features. Supported classes: numeric, logical, factor.