public void TestGetPositivelyCorrelatedEntities()
{
// create a test CorrelationMatrix
var matrix = new SymmetricCorrelationMatrix(3);
matrix[0, 0] = 1f;
matrix[0, 1] = 0.1f;
matrix[0, 2] = -0.2f;
matrix[1, 0] = 0.1f;
matrix[1, 1] = 1f;
matrix[1, 2] = 0.3f;
matrix[2, 0] = -0.2f;
matrix[2, 1] = 0.3f;
matrix[2, 2] = 1f;
Assert.AreEqual(1f, matrix[0, 0]);
Assert.AreEqual(0.3f, matrix[1, 2]);
// test
IList <int> cor_entities_list = matrix.GetPositivelyCorrelatedEntities(2);
int[] cor_entities = new int[1];
cor_entities_list.CopyTo(cor_entities, 0);
int[] pos_cor_entities = { 1 };
Assert.AreEqual(pos_cor_entities, cor_entities);
}
/// <summary>map to latent factor space (actual function)</summary>
protected override float[] __MapToLatentFactorSpace(int item_id)
{
var est_factors = new float[num_factors];
IList <int> relevant_items = item_correlation.GetPositivelyCorrelatedEntities(item_id);
float weight_sum = 0;
uint neighbors = k;
foreach (int item_id2 in relevant_items)
{
if (item_id2 >= item_factors.dim1) // check whether item is in training data
{
continue;
}
if (Feedback.ItemMatrix[item_id2].Count == 0)
{
continue;
}
float weight = item_correlation[item_id, item_id2];
weight_sum += weight;
for (int f = 0; f < num_factors; f++)
{
est_factors[f] += weight * item_factors[item_id2, f];
}
if (--neighbors == 0)
{
break;
}
}
for (int f = 0; f < num_factors; f++)
{
est_factors[f] /= weight_sum;
}
return(est_factors);
}
public void TestGetPositivelyCorrelatedEntities()
{
// create a test CorrelationMatrix
var matrix = new SymmetricCorrelationMatrix(3);
matrix[0, 0] = 1f;
matrix[0, 1] = 0.1f;
matrix[0, 2] = -0.2f;
matrix[1, 0] = 0.1f;
matrix[1, 1] = 1f;
matrix[1, 2] = 0.3f;
matrix[2, 0] = -0.2f;
matrix[2, 1] = 0.3f;
matrix[2, 2] = 1f;
Assert.AreEqual(1f, matrix[0, 0]);
Assert.AreEqual(0.3f, matrix[1, 2]);
// test
IList<int> cor_entities_list = matrix.GetPositivelyCorrelatedEntities(2);
int[] cor_entities = new int[1];
cor_entities_list.CopyTo(cor_entities, 0);
int[] pos_cor_entities = { 1 };
Assert.AreEqual(pos_cor_entities, cor_entities);
}