does anybody know why there are the two warnings in the example above? Regards Knut
> day_4 [1] 540 1 1 1 1 1 1 300 720 480 > day_1 [1] 438 343 1 475 1 562 500 435 1045 890 > is.vector (day_1) [1] TRUE > is.vector (day_4) [1] TRUE > wilcox.test(day_4 ,day_1,paired=TRUE,alternative="two.sided",exact=TRUE,conf.int=TRUE) Wilcoxon signed rank test with continuity correction data: day_4 and day_1 V = 1, p-value = 0.02086 alternative hypothesis: true mu is not equal to 0 95 percent confidence interval: -486.5 -120.0 sample estimates: (pseudo)median -348 Warning messages: 1: cannot compute exact p-value with zeroes in: wilcox.test.default(day_4, day_1, paired = TRUE, alternative = "two.sided", 2: cannot compute exact confidence interval with zeroes in: wilcox.test.default(day_4, day_1, paired = TRUE, alternative = "two.sided", ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html