/// <summary>Write item predictions (scores) to a TextWriter object</summary>
/// <param name="recommender">the <see cref="IRecommender"/> to use for making the predictions</param>
/// <param name="user_id">the ID of the user to make recommendations for</param>
/// <param name="relevant_items">the list of candidate items</param>
/// <param name="ignore_items">a list of items for which no predictions should be made</param>
/// <param name="num_predictions">the number of items to return per user, -1 if there should be no limit</param>
/// <param name="user_mapping">an <see cref="IEntityMapping"/> object for the user IDs</param>
/// <param name="item_mapping">an <see cref="IEntityMapping"/> object for the item IDs</param>
/// <param name="writer">the <see cref="TextWriter"/> to write to</param>
static public void WritePredictions(
IRecommender recommender,
int user_id,
ICollection <int> relevant_items,
ICollection <int> ignore_items,
int num_predictions,
IEntityMapping user_mapping, IEntityMapping item_mapping,
TextWriter writer)
{
var score_list = new List <WeightedItem>();
foreach (int item_id in relevant_items)
{
score_list.Add(new WeightedItem(item_id, recommender.Predict(user_id, item_id)));
}
score_list.Sort();
score_list.Reverse();
int prediction_count = 0;
writer.Write("{0}\t[", user_mapping.ToOriginalID(user_id));
foreach (var wi in score_list)
{
if (!ignore_items.Contains(wi.item_id) && wi.weight > double.MinValue)
{
if (prediction_count == 0)
{
writer.Write("{0}:{1}", item_mapping.ToOriginalID(wi.item_id), wi.weight.ToString(CultureInfo.InvariantCulture));
}
else
{
writer.Write(",{0}:{1}", item_mapping.ToOriginalID(wi.item_id), wi.weight.ToString(CultureInfo.InvariantCulture));
}
prediction_count++;
}
if (prediction_count == num_predictions)
{
break;
}
}
writer.WriteLine("]");
}
// TODO as soon as we drop support for Mono 2.6, use default arguments
/// <summary>Rate a given set of instances and write it to a TextWriter</summary>
/// <param name="recommender">rating predictor</param>
/// <param name="ratings">test cases</param>
/// <param name="user_mapping">an <see cref="EntityMapping"/> object for the user IDs</param>
/// <param name="item_mapping">an <see cref="EntityMapping"/> object for the item IDs</param>
/// <param name="line_format">a format string specifying the line format; {0} is the user ID, {1} the item ID, {2} the rating</param>
/// <param name="writer">the TextWriter to write the predictions to</param>
public static void WritePredictions(
IRatingPredictor recommender,
IRatings ratings,
IEntityMapping user_mapping, IEntityMapping item_mapping,
string line_format,
TextWriter writer)
{
for (int index = 0; index < ratings.Count; index++)
writer.WriteLine(line_format,
user_mapping.ToOriginalID(ratings.Users[index]),
item_mapping.ToOriginalID(ratings.Items[index]),
recommender.Predict(ratings.Users[index], ratings.Items[index]).ToString(CultureInfo.InvariantCulture));
}
// TODO as soon as we drop support for Mono 2.6, use default arguments
/// <summary>Rate a given set of instances and write it to a TextWriter</summary>
/// <param name="recommender">rating predictor</param>
/// <param name="ratings">test cases</param>
/// <param name="user_mapping">an <see cref="EntityMapping"/> object for the user IDs</param>
/// <param name="item_mapping">an <see cref="EntityMapping"/> object for the item IDs</param>
/// <param name="line_format">a format string specifying the line format; {0} is the user ID, {1} the item ID, {2} the rating</param>
/// <param name="writer">the TextWriter to write the predictions to</param>
public static void WritePredictions(
IRatingPredictor recommender,
IRatings ratings,
IEntityMapping user_mapping, IEntityMapping item_mapping,
string line_format,
TextWriter writer)
{
for (int index = 0; index < ratings.Count; index++)
{
writer.WriteLine(line_format,
user_mapping.ToOriginalID(ratings.Users[index]),
item_mapping.ToOriginalID(ratings.Items[index]),
recommender.Predict(ratings.Users[index], ratings.Items[index]).ToString(CultureInfo.InvariantCulture));
}
}
/// <summary>Write item predictions (scores) to a TextWriter object</summary>
/// <param name="recommender">the <see cref="IRecommender"/> to use for making the predictions</param>
/// <param name="user_id">the ID of the user to make recommendations for</param>
/// <param name="relevant_items">the list of candidate items</param>
/// <param name="ignore_items">a list of items for which no predictions should be made</param>
/// <param name="num_predictions">the number of items to return per user, -1 if there should be no limit</param>
/// <param name="user_mapping">an <see cref="IEntityMapping"/> object for the user IDs</param>
/// <param name="item_mapping">an <see cref="IEntityMapping"/> object for the item IDs</param>
/// <param name="writer">the <see cref="TextWriter"/> to write to</param>
public static void WritePredictions(
IRecommender recommender,
int user_id,
ICollection<int> relevant_items,
ICollection<int> ignore_items,
int num_predictions,
IEntityMapping user_mapping, IEntityMapping item_mapping,
TextWriter writer)
{
var score_list = new List<WeightedItem>();
foreach (int item_id in relevant_items)
score_list.Add( new WeightedItem(item_id, recommender.Predict(user_id, item_id)));
score_list.Sort();
score_list.Reverse();
int prediction_count = 0;
writer.Write("{0}\t[", user_mapping.ToOriginalID(user_id));
foreach (var wi in score_list)
{
if (!ignore_items.Contains(wi.item_id) && wi.weight > double.MinValue)
{
if (prediction_count == 0)
writer.Write("{0}:{1}", item_mapping.ToOriginalID(wi.item_id), wi.weight.ToString(CultureInfo.InvariantCulture));
else
writer.Write(",{0}:{1}", item_mapping.ToOriginalID(wi.item_id), wi.weight.ToString(CultureInfo.InvariantCulture));
prediction_count++;
}
if (prediction_count == num_predictions)
break;
}
writer.WriteLine("]");
}