Function levenesTest
Tests the null hypothesis that the variances of all groups are equal against the alternative that heteroscedasticity exists. data must be either a tuple of ranges or a range of ranges. central is an alias for the measure of central tendency to be used. This can be any function that maps a forward range of numeric types to a numeric type. The commonly used ones are median (default) and mean (less robust). Trimmed mean is sometimes useful, but is currently not implemented in dstats.summary.
References
Levene, Howard (1960). "Robust tests for equality of variances". in Ingram Olkin, Harold Hotelling et al. Contributions to Probability and Statistics: Essays in Honor of Harold Hotelling. Stanford University Press. pp. 278-292.
Examples
int[] sample1 = [1,2,3,4,5];
int[] sample2 = [100,200,300,400,500];
auto result = levenesTest(sample1, sample2);
// Clearly the variances are different between these two samples.
assert( approxEqual(result .testStat, 10.08));
assert( approxEqual(result .p, 0.01310));