/// <summary>Create a AdjustedCosine matrix from given data</summary>
/// <param name="ratings">the ratings data</param>
/// <param name="entity_type">the entity type, either USER or ITEM</param>
/// <param name="shrinkage">a shrinkage parameter</param>
/// <returns>the complete AdjustedCosine matrix</returns>
static public CorrelationMatrix Create(IRatings ratings, EntityType entity_type, float shrinkage)
{
AdjustedCosine cm;
int num_entities = 0;
if (entity_type.Equals(EntityType.USER))
{
num_entities = ratings.MaxUserID + 1;
}
else if (entity_type.Equals(EntityType.ITEM))
{
num_entities = ratings.MaxItemID + 1;
}
else
{
throw new ArgumentException("Unknown entity type: " + entity_type);
}
try
{
cm = new AdjustedCosine(num_entities);
}
catch (OverflowException)
{
Console.Error.WriteLine("Too many entities: " + num_entities);
throw;
}
cm.shrinkage = shrinkage;
cm.ComputeCorrelations(ratings, entity_type);
return(cm);
}
/// <summary>Create a AdjustedCosine matrix from given data</summary>
/// <param name="ratings">the ratings data</param>
/// <param name="entity_type">the entity type, either USER or ITEM</param>
/// <param name="shrinkage">a shrinkage parameter</param>
/// <returns>the complete AdjustedCosine matrix</returns>
public static CorrelationMatrix Create(IRatings ratings, EntityType entity_type, float shrinkage)
{
AdjustedCosine cm;
int num_entities = 0;
if (entity_type.Equals(EntityType.USER))
num_entities = ratings.MaxUserID + 1;
else if (entity_type.Equals(EntityType.ITEM))
num_entities = ratings.MaxItemID + 1;
else
throw new ArgumentException("Unknown entity type: " + entity_type);
try
{
cm = new AdjustedCosine(num_entities);
}
catch (OverflowException)
{
Console.Error.WriteLine("Too many entities: " + num_entities);
throw;
}
cm.shrinkage = shrinkage;
cm.ComputeCorrelations(ratings, entity_type);
return cm;
}