Hi, I've been trying to run a wilcox paired test on some data beforesmall aftersmall [1,] 63.5 512.0 [2,] 54.5 237.5 [3,] 52.5 161.5 [4,] 78.0 153.5 [5,] 53.5 68.0 [6,] 50.5 65.5 [7,] 69.0 52.0 [8,] 76.0 59.0 [9,] 68.0 66.5 [10,] 75.5 66.5 [11,] 67.0 45.5 [12,] 81.0 54.5 [13,] 49.0 44.0 [14,] 51.0 42.5 [15,] 53.0 34.5
using wilcox.test(beforesmall ~ aftersmall,paired=T) but I get the error message: Error in wilcox.test.formula(beforesmall ~ aftersmall, paired = T) : grouping factor must have exactly 2 levels I don't have any missing values, I have the same amount of data points for each group and I've looked everywhere trying to find the answer. Please can somebody tell me how to make it work thanks [[alternative HTML version deleted]] ______________________________________________ R-help@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.