[R] Wilcoxon Test and Mean Ratios

[Mohamed Radhouane Aniba]

Hello All,

I am writing to ask your opinion on how to interpret this case. I have two vectors "a" and "b" that I am trying to compare.

The wilcoxon test is giving me a pvalue of 5.139217e-303 of a over b with the alternative "greater". Now if I make a summary on each of them I have the following

> summary(a)
     Min.   1st Qu.    Median      Mean   3rd Qu.      Max. 
0.0000000 0.0001411 0.0002381 0.0002671 0.0003623 0.0012910 
> summary(c)
     Min.   1st Qu.    Median      Mean   3rd Qu.      Max. 
0.0000000 0.0000000 0.0000000 0.0004947 0.0002972 1.0000000

The mean ratio is then around 0.5399031 which naively goes in opposite direction of the wilcoxon test ( I was expecting to find a ratio >> 1)

Even after removing outlier using the outlier package, I still have the same thing. Can someone help me explain why I do have this result and how to explain it ?

Thanks in advance

Rad