public double Predict(string itemName, Dictionary <string, double> userAssessments)
{
if (userAssessments.ContainsKey(itemName))
{
return(userAssessments[itemName]);
}
var pairs = _matrix.GetSlice(itemName)
.Select(
keyedValue =>
new
{
Similarity = keyedValue.Value,
Rating = _normalizer.Normalize(userAssessments[keyedValue.Key])
})
.ToList();
var normalizedResult = pairs.Sum(pair => pair.Similarity * pair.Rating) /
pairs.Sum(p => p.Similarity.ToAbsolute());
return(_normalizer.Denormalize(normalizedResult));
}