[R] Large file size while persisting rpart model to disk

[Terry Therneau]

Brian R makes good points.

I made a mistake in the prior post, it should have said
	new.env(parent=globalenv())	

for pspline.  You want the saved function to pay attention to the search() path. 
This is what is actually in the code, I was guilty of mistyping.  
  If the print function uses a not-exported function from the enclosing package 
then we need to be more careful.  This is the case for rpart.