[R] wilcox.test warnig message p-value where are the zeros in the data?
Knut Krueger
admin at biostatistic.de
Thu Jan 12 16:16:39 CET 2006
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",
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