Estimated Marginal Means from PSCL Object

Hi R-Help,

I have a pscl zero-inflated poisson regression object from which I am
trying to extract the estimated marginal means by category (e.g. GROUPA), I
can't figure out what I'm doing wrong with the lsmeans package:

FU1NSSI<-zeroinfl(W8_PAST4WEEKS_NSSI ~ GROUPA,
                na.action="na.exclude",data = FHB, dist = "poisson")

and

lsmeans(FU1NSSI, GROUPA)
Error in ref.grid(object = <S4 object of class "ref.grid">) :
  Can't handle an object of class  ?ref.grid?
 Use help("models", package = "lsmeans") for information on supported
models.

Thanks! Edward

Edward H Patzelt | Clinical Science PhD Student
Psychology | Harvard University
*Computational Cognitive Neuroscience Laboratory
<http://gershmanlab.webfactional.com/>*

	[[alternative HTML version deleted]]