Hi Timothy,
Look at the help page for multcompLetters, especially the examples to
see what the function expects the input to look like:
?multcompLetters
example(multcompLetters)
Then look at the structure of kr:
str(kr)
and notice that the the logical vector you need is in the column named
"difference" in the dif.com data.frame. Extract those values and
format as required for multcompLetters
kr.diff <- kr$dif.com$difference
names(kr.diff) <- rownames(kr$dif.com)
Then run multcompLetters:
multcompLetters(kr.diff)
HTH,
Ista
On Wed, Oct 27, 2010 at 2:27 PM, Timothy Spier <timspier at hotmail.com>
wrote:>
> I am interested in using "multcompLetters" after running
"kruskalmc" but
> I'm a newbie and I'm not having luck figuring it out. I can run
"kruskalmc" just fine,
> but after studying the documentation for "multcompletters" for a
long time,
> I cannot figure out how to make it work. Any ideas? R input is below
>>
>>> #here is my data set
>>> tst
>> ? ? Month Food_kg
>> 1 ? ?Feb ? ? 4.7
>> 2 ? ?Feb ? ? 4.9
>> 3 ? ?Feb ? ? 5.0
>> 4 ? ?Feb ? ? 4.8
>> 5 ? ?Feb ? ? 4.7
>> 6 ? ?May ? ? 4.6
>> 7 ? ?May ? ? 4.4
>> 8 ? ?May ? ? 4.3
>> 9 ? ?May ? ? 4.4
>> 10 ? May ? ? 4.1
>> 11 ? May ? ? 4.2
>> 12 ? Aug ? ? 4.8
>> 13 ? Aug ? ? 4.7
>> 14 ? Aug ? ? 4.6
>> 15 ? Aug ? ? 4.4
>> 16 ? Aug ? ? 4.7
>> 17 ? Aug ? ? 4.8
>> 18 ? Nov ? ? 4.9
>> 19 ? Nov ? ? 5.2
>> 20 ? Nov ? ? 5.4
>> 21 ? Nov ? ? 5.1
>> 22 ? Nov ? ? 5.6
>>> #run the KW test
>>> k = kruskal.test(Food_kg, Month)
>>> k
>> ? ? ? ? ?Kruskal-Wallis rank sum test
>>
>> data: ?Food_kg and Month
>> Kruskal-Wallis chi-squared = 17.2561, df = 3, p-value = 0.000626
>>
>>> #run the kruskalmc
>>> kr = kruskalmc(Food_kg, Month)
>>> kr
>> Multiple comparison test after Kruskal-Wallis
>> p.value: 0.05
>> Comparisons
>> ? ? ? ? ? ?obs.dif critical.dif difference
>> Aug-Feb ?3.650000 ? ?10.373791 ? ? ?FALSE
>> Aug-May ?6.333333 ? ? 9.891022 ? ? ?FALSE
>> Aug-Nov ?9.450000 ? ?10.373791 ? ? ?FALSE
>> Feb-May ?9.983333 ? ?10.373791 ? ? ?FALSE
>> Feb-Nov ?5.800000 ? ?10.835071 ? ? ?FALSE
>> May-Nov 15.783333 ? ?10.373791 ? ? ? TRUE
>
>
>>> #now I want to run multcompLetters but I'm stuck
>>
> ? ? ? ?[[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.
>
--
Ista Zahn
Graduate student
University of Rochester
Department of Clinical and Social Psychology
http://yourpsyche.org