Performs the Wilcoxon rank sum test to compare the median between two samples.
Technical details
Description
This test can be applied to two samples of equal or different sizes. For paired samples see Test  Nonparametric  Paired Samples Wilcoxon Test.
Inputs
 Outcome Variable containing the sample to analyze.
 Group Variable specifying the group that each observation comes from. Where this Variable is numeric, it is automatically grouped into two approximatelyequallysized groups, using the median.
 mu Difference in the median of the two samples, as assumed under the null hypothesis.
 Alternative hypothesis Use a twosided or onesided test.
 Type of test Method by which the pvalue is computed.

Output
 Summary Shows a nicely formatted table of the test results (default).
 R The original textbased output from the wilcox.test function.
 Variable names Display Variable Names in the output, instead of Variable Labels.
 More decimal places Display numeric values with 8 decimal places.
Output
Acknowledgements
Uses the wilcox.test function from the stats R package.
Method
 In Displayr: How to Perform TwoSample Wilcoxon Rank Sum Test
 In Q: Create > Test > Nonparametric > TwoSample Wilcoxon Test