I am using 'by' variables with GAMs in the mgcv package.  In newer versions
of mgcv, there is no sum-to-zero constraint on these terms, unless its
needed for identifiability.  Is there any way to force this constraint in
the current version of mgcv?  I'm trying to visualize some of these terms,
by showing predicted positive or negative effect size across a geographic
area and it would be helpful to have without having to download the older
version of mgcv.

Thanks,
Jen Weave

-- 
Marine Fisheries Fellow
North Carolina State University
Center for Marine Sciences and Technology
303 College Circle
Morehead City, NC 28557

Ph: 252.222.6317
Fax: 252.222.6311
jlweaver@ncsu.edu

	[[alternative HTML version deleted]]

