I'm quite sure the VGAM package has been installed because I used it to
estimate the model before I use summary(). One reason I can guess is that
the default method for summary() is S3, but here it is S4. But I'm not sure
and don't know what to do with that. Here is an example you can reproduce:

counts = c(18,17,15,20,10,20,25,13,12)
outcome = gl(3,1,9)
treatment = gl(3,3)
print(d.AD <- data.frame(treatment, outcome, counts))
vglm.D93 = vglm(counts ~ outcome + treatment, family=poissonff)
summary(vglm.D93)

With this, I got:

> summary(vglm.D93)
Length  Class   Mode
     1   vglm     S4

If I just type "vglm.D93", I got:

Call:
vglm(formula = counts ~ outcome + treatment, family = poissonff)

Coefficients:
  (Intercept)      outcome2      outcome3    treatment2    treatment3
 3.044522e+00 -4.542553e-01 -2.929871e-01  7.766813e-16  3.009745e-16

Degrees of Freedom: 9 Total; 4 Residual
Residual Deviance: 5.129141
Log-likelihood: -23.38066


Looking forward to see more advices. Thanks.

Harry




On Sat, Aug 15, 2009 at 8:18 PM, Ronggui Huang <ronggui.huang@gmail.com>wrote:

> I cannot reproduce what you mentioned. One possible is that you use
> summary() without loading VGAM package.
>
>
> 2009/8/16 Hongwei Dong <pdxdong@gmail.com>:
> > Hi, R users,
> >  I'm using the function "vglm" to estimate a multinomial logit model.
> Every
> > time I use "summary()" to ask for the coefficients and std error, I got
> > this:
> >
> > Length  Class   Mode
> >     1   vglm     S4
> >
> > Anyone know what's wrong here? Thanks.
> >
> > Harry
> >
> >        [[alternative HTML version deleted]]
> >
> > ______________________________________________
> > R-help@r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
> >
>
>
>
> --
> HUANG Ronggui, Wincent
> PhD Candidate
> Dept of Public and Social Administration
> City University of Hong Kong
> Home page: http://asrr.r-forge.r-project.org/rghuang.html
>

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