Message-ID: <16209B07-F65E-4F7B-AC06-5F7C2ED2CDC7@comcast.net>
Date: 2011-11-21T20:16:25Z
From: David Winsemius
Subject: count ties after rank?
In-Reply-To: <805CF575416A5648A33D58C35B7D3552AD604E06@it-monad.sooner.net.ou.edu>
On Nov 21, 2011, at 2:36 PM, Hao, Zhaozhe wrote:
> Hello!
>
> I need to use Kruskal-Wallis test and post-hoc test (Dunn's test)
> for my data. But when I searched around,
"Searching around" is a bit vague as a search strategy:
Try :kruskal dunn" at the location that RSiteSearch gets you to:
http://search.r-project.org/cgi-bin/namazu.cgi?query=kruskal+Dunn&max=100&result=normal&sort=score&idxname=functions&idxname=Rhelp08&idxname=Rhelp10&idxname=Rhelp02
Or in its default settings:
http://search.r-project.org/cgi-bin/namazu.cgi?query=kruskal+Dunn&max=100&result=normal&sort=score&idxname=functions&idxname=vignettes&idxname=views
> I only found this function: kruskal.test. But nothing for Dunn's test.
>
> So I started to write one myself.
You are perhaps referring to what others are callng the Nemenyi-
Damico-Wolfe-Dunn test. See the last example in the entry that ?
kruskal_test would have gotten you... had you known where it was.
install.packages("coin")
require(coin)
help("LocationTests")
> But I do not know how to count ties in the data frame. I can use
> for loops but it seems long and unnecessary since the rank function
> actually knows the ties. So can anyone give me a hint on how I can
> "count" the number of ties?
>
> Many thanks.
--
David Winsemius, MD
West Hartford, CT