[Test()] public void TestComputeCorrelation()
{
var vector1 = new HashSet <int>();
vector1.Add(0);
vector1.Add(2);
vector1.Add(4);
var vector2 = new HashSet <int>();
vector2.Add(1);
vector2.Add(3);
vector2.Add(4);
var cosine = new BinaryCosine(4);
Assert.AreEqual(1 / 3f, cosine.ComputeCorrelation(vector1, vector2), DELTA);
Assert.AreEqual(0f, cosine.ComputeCorrelation(vector1, new HashSet <int>()), DELTA);
}
///
protected override void RetrainUser(int user_id)
{
base.RetrainUser(user_id);
if (UpdateUsers)
{
for (int i = 0; i <= MaxUserID; i++)
{
correlation[user_id, i] = BinaryCosine.ComputeCorrelation(new HashSet <int>(data_user[user_id]), new HashSet <int>(data_user[i]));
}
}
}
///
protected override void RetrainItem(int item_id)
{
base.RetrainUser(item_id);
if (UpdateItems)
{
for (int i = 0; i <= MaxItemID; i++)
{
correlation[item_id, i] = BinaryCosine.ComputeCorrelation(new HashSet <int>(data_item[item_id]), new HashSet <int>(data_item[i]));
}
}
}
[Test()] public void TestComputeCorrelation()
{
// create test objects
var vector1 = new HashSet <int>();
vector1.Add(0);
vector1.Add(2);
vector1.Add(4);
var vector2 = new HashSet <int>();
vector2.Add(1);
vector2.Add(3);
vector2.Add(4);
// test
Assert.AreEqual(Math.Round(1 / 3d, 4), Math.Round(BinaryCosine.ComputeCorrelation(vector1, vector2), 4));
}