# ranksum

Wilcoxon rank sum test

## Description

returns
the `p`

= ranksum(`x`

,`y`

)*p*-value of a two-sided Wilcoxon rank sum test. `ranksum`

tests
the null hypothesis that data in `x`

and `y`

are
samples from continuous distributions with equal medians, against
the alternative that they are not. The test assumes that the two samples
are independent. `x`

and `y`

can
have different lengths.

`[___] = ranksum(`

returns
any of the output arguments in the previous syntaxes, for a rank sum
test with additional options specified by one or more `x`

,`y`

,`Name,Value`

)`Name`

,`Value`

pair
arguments.

## Examples

## Input Arguments

## Output Arguments

## More About

## Algorithms

`ranksum`

treats `NaN`

s in `x`

and `y`

as
missing values and ignores them.

For a two-sided test of medians with unequal sample sizes, the
test statistic that `ranksum`

returns is the rank
sum of the first sample.

## References

[1] Gibbons, J. D., and S. Chakraborti. *Nonparametric
Statistical Inference*, 5th Ed., Boca Raton, FL: Chapman
& Hall/CRC Press, Taylor & Francis Group, 2011.

[2] Hollander, M., and D. A. Wolfe. *Nonparametric
Statistical Methods*. Hoboken, NJ: John Wiley & Sons,
Inc., 1999.

## Version History

**Introduced before R2006a**

## See Also

`kruskalwallis`

| `signrank`

| `signtest`

| `ttest2 `