[R] Kruskal.test() on lists

Altaweel, Mark R. maltaweel at anl.gov
Thu Aug 21 21:37:36 CEST 2008


I am trying to do a kruskal wallis test on two lists, fVisited and cSN:

[1] 0.17097623 0.30376141 0.17577266 0.14951855 0.03959753 0.08096217 0.05744888 0.02196257....

[1] 0.08557303 0.36477791 0.19601252 0.12981040 0.05351320 0.10385542 0.03539577 0.03106175....

So if I just want to do a test on just one of the entries this is simple enough:


	Kruskal-Wallis rank sum test

data:  fVisited[[1]] and cSN[[1]] 
Kruskal-Wallis chi-squared = 7, df = 7, p-value = 0.4289

However, if I try to do it over the entire list I get a problem.  I wanted to do a test comparing each pair of distributions, so I thought something such as:  kT<-sapply(fVisited,function(.df){sapply(cSN,functions(.vecs){kruskal.test(.df,.vecs)})}
But that produces this:

Error in kruskal.test.default(.df, .vecs) : 
  'x' and 'g' must have the same length

However, the values do have the same length. Can anyone see what I am doing wrong here?

Thanks again for everyone's help.

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