public void Statistics_TauCorrelationTest()
{
var mergeSorter = new MergeSorter <int>();
var target = new TauCorrelation <int, int, double>(
(a, c) => Array.Sort(a, c),
(a, c) => mergeSorter.SortCountSwaps(a),
(v, q) => v / q,
v => Math.Sqrt(v));
// Correlação perfeita
var n = 100;
var firstColumn = new int[n];
var secondColumn = new int[n];
for (var i = 0; i < n; ++i)
{
firstColumn[i] = i;
secondColumn[i] = i;
}
var result = target.Run(
firstColumn,
secondColumn,
Comparer <int> .Default,
Comparer <int> .Default);
Assert.AreEqual(1.0, result);
// Correlação contrária
for (var i = 0; i < n; ++i)
{
firstColumn[i] = n - i - 1;
secondColumn[i] = i;
}
result = target.Run(
firstColumn,
secondColumn,
Comparer <int> .Default,
Comparer <int> .Default);
Assert.AreEqual(0.0, result);
}