[RsR] calculating deviance for glmrob

Standard glm returns a deviance field, which is apparently minus twice the maximized log-likelihood.
glmrob claims to do the same in its help page, but seems to always return NULL for deviance.

It seems to be an unimplemented feature.  Does anyone have code or an algorithm that can calculate it?

Any pointers appreciated


Alex Holcombe
www.psych.usyd.edu.au/staff/alexh/