TRIPLESTEST

H = TRIPLESTEST(X) performs the non-parametric triples test for symmetry (skewness) of the null hypothesis that the data in X comes from a symmetrical distribution with an unknown median. The test involves the examination of subsets of three variables from X (triples) to determine the likelihood that the distribution is skewed. H==0 indicated that the null hypothesis cannot be rejected at the 5% significance level. H==1 indicates that the null hypothesis can be rejected at the 5% level.

This test is suitable for date measured on a ordinal, interval, and rational scales, wheres the 3rd central moment (skewness) is valid for a rational scale only.

The syntax follows the style of most statistical tests in matlab. Note that the statistical toolbox is not required.

See help for an example.

Version 2.2, may 2012