Function name: vartests
Description:

The "vartests" perform hypothesis test for the equality of the variances in two ways, either via the Levene or via the Brown-Forshythe procedure. Levene's test employs the means, whereas the Brown-Forsythe procedure employs the medians and is therefore more robust to outliers.

Authors: Author: Michail Tsagris and Manos Papadakis