R help - Jul 2011 - Simulating from the null distribution of a 2 x 3 table

Dear all,

I want to simulate from the null distribution of the following 2 x 3 table,

2   5  10
4   8   5

I am using  a chi-squared test.
Anyone has any idea how to do this?

-- 
Thanks,
Jim.

	[[alternative HTML version deleted]]

On Jul 6, 2011, at 8:58 PM, Jim Silverton wrote:
> Dear all,
>
> I want to simulate from the null distribution of the following 2 x 3  
> table,
>
> 2   5  10
> 4   8   5
>
> I am using  a chi-squared test.
Yeah. Right. A "chi-squared test". That certainly narrows it down ...
to maybe one quarter of all statistical tests ever invented.

> Anyone has any idea how to do this?

Depending on what you actually mean by "the null distribution of a 2 X  
3 table". possibly:

?r2dtable

-- 
David.
>
> -- 
> Thanks,
> Jim.
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at 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.
David Winsemius, MD
West Hartford, CT

Homework?

If not, context?

-- Bert

On Wed, Jul 6, 2011 at 5:58 PM, Jim Silverton <jim.silverton at gmail.com>
wrote:
> Dear all,
>
> I want to simulate from the null distribution of the following 2 x 3 table,
>
> 2 ? 5 ?10
> 4 ? 8 ? 5
>
> I am using ?a chi-squared test.
> Anyone has any idea how to do this?
>
> --
> Thanks,
> Jim.
>
> ? ? ? ?[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at 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.
>


-- 
"Men by nature long to get on to the ultimate truths, and will often
be impatient with elementary studies or fight shy of them. If it were
possible to reach the ultimate truths without the elementary studies
usually prefixed to them, these would not be preparatory studies but
superfluous diversions."

-- Maimonides (1135-1204)

Bert Gunter
Genentech Nonclinical Biostatistics

On Thu, Jul 7, 2011 at 12:58 PM, Jim Silverton <jim.silverton at
gmail.com> wrote:
> Dear all,
>
> I want to simulate from the null distribution of the following 2 x 3 table,
>
> 2 ? 5 ?10
> 4 ? 8 ? 5
>
> I am using ?a chi-squared test.
> Anyone has any idea how to do this?
The r2dtable() function will simulate tables with a given set of row
and column totals.

    -thomas

-- 
Thomas Lumley
Professor of Biostatistics
University of Auckland

On Jul 7, 2011, at 05:01 , Thomas Lumley wrote:
> On Thu, Jul 7, 2011 at 12:58 PM, Jim Silverton <jim.silverton at
gmail.com> wrote:
>> Dear all,
>> 
>> I want to simulate from the null distribution of the following 2 x 3
table,
>> 
>> 2   5  10
>> 4   8   5
>> 
>> I am using  a chi-squared test.
>> Anyone has any idea how to do this?
> 
> The r2dtable() function will simulate tables with a given set of row
> and column totals.
Or, as a shortcut, maybe look into chisq.test(..., simulate.p.value=TRUE).

Notice that both use hypergeometric-type sampling. One could also consider
sampling with rmultinom (either of order 6, twice of order three, or thrice of
order 2), or even rpois, assuming a Poisson distribution of the total count.

> 
>    -thomas
> 
> -- 
> Thomas Lumley
> Professor of Biostatistics
> University of Auckland
> 
> ______________________________________________
> R-help at 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.
-- 
Peter Dalgaard
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com