Yingjie Zhang wrote:
> Dear all,
>
> Thanks for all your perspectives, I agree with Dr. Gavin Simpson's opinion
> that the author cooked the model by themselves, and there is no Hurdle
> function in package 'stats'.
>
> I got a data set of the abundance of microbial community, I think some of yo
Dear all,
Thanks for all your perspectives, I agree with Dr. Gavin Simpson's opinion that
the author cooked the model by themselves, and there is no Hurdle function in
package 'stats'.
I got a data set of the abundance of microbial community, I think some of you
will know how it looks like, i
Dear All,
I had a quick look at the internal functions used by pscl::hurdle to
do the numerical optimization by optim. It clearly corresponds to the
hurdle model defined in the paper/vignette, where the zero component
is based on a right censored random variable, that is 0 if the
original count da
On Thu, 2010-08-19 at 14:54 +0300, Gavin Simpson wrote:
> On Thu, 2010-08-19 at 13:20 +0200, Yingjie Zhang wrote:
> They fit several models and compare them:
>
> I. Poisson
> II. Negative Binomial
>III. Quasi-likelihood
> IV. Hurdle model
> V. zero-inflated model
>
> III sh
Hi Conrado and Jari,
Indeed, using vegan 1.17.2 and R version 2.10.1 (32-bits), I got no warnings
and the output Conrado sent above.
All the best,
Marcus
On Thu, Aug 19, 2010 at 8:36 AM, Conrado Galdino wrote:
> 2010/8/19 Jari Oksanen
>
> > On 19/08/10 01:07 AM, "Conrado Galdino" wrote:
> >
On Thu, 2010-08-19 at 13:20 +0200, Yingjie Zhang wrote:
> Thanks for the details, the paper is 'Comparing species abundance
> models' by Joanne M.Potts, Jane Elith. Click the link... on page 158,
> in the table, they compare 5 models, both Quasi-likelihood and Hurdle
> are mentioned.
>
> http://w
2010/8/19 Jari Oksanen
> On 19/08/10 01:07 AM, "Conrado Galdino" wrote:
>
> > Thanks very much for your response Jari,
> >
> > Is good to know from you that there is nothing to worry. I'll surely
> check
> > the plots. Taking the opportunity I also like to inform that in newer
> > versions of th
Thanks for the details, the paper is 'Comparing species abundance models' by
Joanne M.Potts, Jane Elith. Click the link... on page 158, in the table, they
compare 5 models, both Quasi-likelihood and Hurdle are mentioned.
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VBS-4KD5C2N-1&_
On Thu, 2010-08-19 at 11:14 +0200, Yingjie Zhang wrote:
> Hi,
>
> There is a reason why am I addict to Quasi likelihood, since Hurdle
> from 'pscl' use Zero Truncated Poisson regression for the non-zero
> part, which incapable of handling the over-disperson comes from the
> positive part of the da
Hi,
There is a reason why am I addict to Quasi likelihood, since Hurdle from
'pscl' use Zero Truncated Poisson regression for the non-zero part, which
incapable of handling the over-disperson comes from the positive part of the
data. Apparently, Quasi likelihood is at least a better choice. I
On Thu, 2010-08-19 at 10:30 +0200, Yingjie Zhang wrote:
> I'd like to try the same way to my dataset, hurdle but estimated by
> 'quasi-likelihood', but it's not in the standard 'pscl' package I
> think, right?
Please keep discussion on list; just because I replied doesn't give you
a direct line to
On Thu, 2010-08-19 at 09:52 +0200, Yingjie Zhang wrote:
> Hello everyone,
>
> Does anyone of you using hurdle model? I am reading a paper which said
> " Hurdle model removes effect of zero-inflation and over-dispersion in
> the non-zero observations using a quasi-likelihood", I've checked the
> he
Hello everyone,
Does anyone of you using hurdle model? I am reading a paper which said " Hurdle
model removes effect of zero-inflation and over-dispersion in the non-zero
observations using a quasi-likelihood", I've checked the help file from hurdle
in R, which said differently that"for non-zer
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