Hi All: OK, this is probably a stupid thing to do but....... Say I have 706 controls and 6 treatments, and want to do a basic two-sample permutation test. I could do a monte carlo approximation but instead want to use perm.test. Now it happens that my data is counts with> unique(x)[1] 1 2> unique(y)[1] 1 2 5 3 10 9 7 4 6 11 8 23 18 30 16 29 42 so there aren't that many categories. I thought perm.test makes this an Rx2 table and then does some sort of network algorithm on it. But I get the following error message:> perm.test(x,y,exact=T)Error in cperm(eq, m, paired) : N > 200 in cpermdistr2>I understand this is a sample size error but it doesn't seem to make sense to me since there aren't that many unique categories for x and y. What am I missing ? Thanks, Steve __________________________________________________ Yahoo! Finance - Get real-time stock quotes -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
Sorry of this is a repeat-the original message didn't seem to go through..... I have two groups that I am trying to do a two sample permutation test on (equality of means). The x group has 6 elements and the y group has 703 elements. However, the data is counts and there are only a few unique values:> unique(x)[1] 1 2> unique(y)[1] 1 2 5 3 10 9 7 4 6 11 8 23 18 30 16 29 42 Now I understand that you don't need to be a weatherman to see which way the wind is blowing here and clearly you would reject the null of equality. I thought that perm.test creates a rx2 contingency table and then does a network algorithm ala stat exact (or something like that). In this example it doesn't seem that the contingency table would be that big. Any suggestions or comments ? Thanks, Steve But I get the following error:> perm.test(x,y,exact=T)Error in cperm(eq, m, paired) : N > 200 in cpermdistr2 __________________________________________________ Yahoo! Finance - Get real-time stock quotes -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._