/// <summary>Compute the overlap between the vectors in a binary matrix</summary>
/// <returns>a sparse matrix with the overlaps</returns>
/// <param name='entity_data'>the binary matrix</param>
public static Tuple<IMatrix<float>, IList<float>> ComputeWeighted(IBooleanMatrix entity_data)
{
var transpose = (IBooleanMatrix) entity_data.Transpose();
var other_entity_weights = new float[transpose.NumberOfRows];
for (int row_id = 0; row_id < transpose.NumberOfRows; row_id++)
{
int freq = transpose.GetEntriesByRow(row_id).Count;
other_entity_weights[row_id] = 1f / (float) Math.Log(3 + freq, 2); // TODO make configurable
}
IMatrix<float> weighted_overlap = new SymmetricMatrix<float>(entity_data.NumberOfRows);
IList<float> entity_weights = new float[entity_data.NumberOfRows];
// go over all (other) entities
for (int row_id = 0; row_id < transpose.NumberOfRows; row_id++)
{
var row = transpose.GetEntriesByRow(row_id);
for (int i = 0; i < row.Count; i++)
{
int x = row[i];
entity_weights[x] += other_entity_weights[row_id];
for (int j = i + 1; j < row.Count; j++)
{
int y = row[j];
weighted_overlap[x, y] += other_entity_weights[row_id] * other_entity_weights[row_id];
}
}
}
return Tuple.Create(weighted_overlap, entity_weights);
}
/// <summary>Compute the overlap between the vectors in a binary matrix</summary>
/// <returns>a sparse matrix with the overlaps</returns>
/// <param name='entity_data'>the binary matrix</param>
public static Tuple <IMatrix <float>, IList <float> > ComputeWeighted(IBooleanMatrix entity_data)
{
var transpose = (IBooleanMatrix)entity_data.Transpose();
var other_entity_weights = new float[transpose.NumberOfRows];
for (int row_id = 0; row_id < transpose.NumberOfRows; row_id++)
{
int freq = transpose.GetEntriesByRow(row_id).Count;
other_entity_weights[row_id] = 1f / (float)Math.Log(3 + freq, 2); // TODO make configurable
}
IMatrix <float> weighted_overlap = new SymmetricMatrix <float>(entity_data.NumberOfRows);
IList <float> entity_weights = new float[entity_data.NumberOfRows];
// go over all (other) entities
for (int row_id = 0; row_id < transpose.NumberOfRows; row_id++)
{
var row = transpose.GetEntriesByRow(row_id);
for (int i = 0; i < row.Count; i++)
{
int x = row[i];
entity_weights[x] += other_entity_weights[row_id];
for (int j = i + 1; j < row.Count; j++)
{
int y = row[j];
weighted_overlap[x, y] += other_entity_weights[row_id] * other_entity_weights[row_id];
}
}
}
return(Tuple.Create(weighted_overlap, entity_weights));
}
/// <summary>Display data statistics for item recommendation datasets</summary>
/// <param name="training_data">the training dataset</param>
/// <param name="test_data">the test dataset</param>
/// <param name="user_attributes">the user attributes</param>
/// <param name="item_attributes">the item attributes</param>
public static string Statistics(
this IPosOnlyFeedback training_data, IPosOnlyFeedback test_data = null,
IBooleanMatrix user_attributes = null, IBooleanMatrix item_attributes = null)
{
// training data stats
int num_users = training_data.AllUsers.Count;
int num_items = training_data.AllItems.Count;
long matrix_size = (long)num_users * num_items;
long empty_size = (long)matrix_size - training_data.Count;
double sparsity = (double)100L * empty_size / matrix_size;
string s = string.Format(CultureInfo.InvariantCulture, "training data: {0} users, {1} items, {2} events, sparsity {3,0:0.#####}\n", num_users, num_items, training_data.Count, sparsity);
// test data stats
if (test_data != null)
{
num_users = test_data.AllUsers.Count;
num_items = test_data.AllItems.Count;
matrix_size = (long)num_users * num_items;
empty_size = (long)matrix_size - test_data.Count;
sparsity = (double)100L * empty_size / matrix_size; // TODO depends on the eval scheme whether this is correct
s += string.Format(CultureInfo.InvariantCulture, "test data: {0} users, {1} items, {2} events, sparsity {3,0:0.#####}\n", num_users, num_items, test_data.Count, sparsity);
}
return(s + Statistics(user_attributes, item_attributes));
}
void ComputeCorrelationsUShortOverlap(IBooleanMatrix entity_data)
{
var overlap = Overlap.ComputeUShort(entity_data);
for (int x = 0; x < NumEntities; x++)
for (int y = 0; y < x; y++)
this[x, y] = ComputeCorrelationFromOverlap(overlap[x, y], entity_data.NumEntriesByRow(x), entity_data.NumEntriesByRow(y));
}
void ComputeCorrelationsWeighted(IBooleanMatrix entity_data)
{
var overlap_and_entity_weights = Overlap.ComputeWeighted(entity_data);
var overlap = overlap_and_entity_weights.Item1;
var entity_weights = overlap_and_entity_weights.Item2;
for (int x = 0; x < NumEntities; x++)
for (int y = 0; y < x; y++)
this[x, y] = ComputeCorrelationFromOverlap(overlap[x, y], entity_weights[x], entity_weights[y]);
}
///
public int Overlap(IBooleanMatrix s)
{
int c = 0;
for (int i = 0; i < row_list.Count; i++)
foreach (int j in row_list[i])
if (s[i, j])
c++;
return c;
}
void ComputeCorrelationsUShortOverlap(IBooleanMatrix entity_data)
{
var overlap = Overlap.ComputeUShort(entity_data);
for (int x = 0; x < NumEntities; x++)
{
for (int y = 0; y < x; y++)
{
this[x, y] = ComputeCorrelationFromOverlap(overlap[x, y], entity_data.NumEntriesByRow(x), entity_data.NumEntriesByRow(y));
}
}
}
///
protected internal override void InitModel()
{
base.InitModel();
if (user_connections == null)
{
user_connections = new SparseBooleanMatrix();
Console.Error.WriteLine("Warning: UserRelation not set.");
}
group = new float[user_connections.NumberOfEntries];
}
void ComputeCorrelationsUIntOverlap(IBooleanMatrix entity_data)
{
var overlap = Overlap.ComputeUInt(entity_data);
// compute correlations
for (int x = 0; x < num_entities; x++)
for (int y = 0; y < x; y++)
{
this[x, y] = ComputeCorrelationFromOverlap(overlap[x, y], entity_data.NumEntriesByRow(x), entity_data.NumEntriesByRow(y));
this[y, x] = ComputeCorrelationFromOverlap(overlap[x, y], entity_data.NumEntriesByRow(y), entity_data.NumEntriesByRow(x));
}
}
///
protected internal override void InitModel()
{
if (user_connections == null)
{
user_connections = new SparseBooleanMatrix();
Console.Error.WriteLine("Warning: UserRelation not set.");
}
this.MaxUserID = Math.Max(MaxUserID, user_connections.NumberOfRows - 1);
this.MaxUserID = Math.Max(MaxUserID, user_connections.NumberOfColumns - 1);
base.InitModel();
}
///
protected internal override void InitModel()
{
if (user_connections == null)
{
user_connections = new SparseBooleanMatrix();
Console.Error.WriteLine("Warning: UserRelation not set.");
}
this.MaxUserID = Math.Max(MaxUserID, user_connections.NumberOfRows - 1);
this.MaxUserID = Math.Max(MaxUserID, user_connections.NumberOfColumns - 1);
base.InitModel();
}
void ComputeCorrelationsWeighted(IBooleanMatrix entity_data)
{
var overlap_and_entity_weights = Overlap.ComputeWeighted(entity_data);
var overlap = overlap_and_entity_weights.Item1;
var entity_weights = overlap_and_entity_weights.Item2;
for (int x = 0; x < NumEntities; x++)
{
for (int y = 0; y < x; y++)
{
this[x, y] = ComputeCorrelationFromOverlap(overlap[x, y], entity_weights[x], entity_weights[y]);
}
}
}
/// <summary>Optimizes the specified data</summary>
/// <param name="data">data</param>
/// <param name="W">W</param>
/// <param name="H">H</param>
protected virtual void Optimize(IBooleanMatrix data, Matrix<float> W, Matrix<float> H)
{
// comments are in terms of computing the user factors
// ... works the same with users and items exchanged
// (1) create HH in O(f^2|Items|)
var HH = ComputeSquareMatrix(H);
// (2) optimize all U
Parallel.For(
0,
W.dim1,
u => { Optimize(u, data, W, H, HH); }
);
}
void ComputeCorrelationsUIntOverlap(IBooleanMatrix entity_data)
{
var overlap = Overlap.ComputeUInt(entity_data);
// compute correlations
for (int x = 0; x < num_entities; x++)
{
for (int y = 0; y < x; y++)
{
this[x, y] = ComputeCorrelationFromOverlap(overlap[x, y], entity_data.NumEntriesByRow(x), entity_data.NumEntriesByRow(y));
this[y, x] = ComputeCorrelationFromOverlap(overlap[x, y], entity_data.NumEntriesByRow(y), entity_data.NumEntriesByRow(x));
}
}
}
/// <summary>Display dataset statistics</summary>
/// <param name="train">the training data</param>
/// <param name="test">the test data</param>
/// <param name="user_attributes">the user attributes</param>
/// <param name="item_attributes">the item attributes</param>
/// <param name="display_overlap">if set true, display the user/item overlap between train and test</param>
public static string Statistics(
this IRatings train, IRatings test = null,
IBooleanMatrix user_attributes = null, IBooleanMatrix item_attributes = null,
bool display_overlap = false)
{
// training data stats
int num_users = train.AllUsers.Count;
int num_items = train.AllItems.Count;
long matrix_size = (long)num_users * num_items;
long empty_size = (long)matrix_size - train.Count;
double sparsity = (double)100L * empty_size / matrix_size;
string s = string.Format(CultureInfo.InvariantCulture, "training data: {0} users, {1} items, {2} ratings, sparsity {3,0:0.#####}\n", num_users, num_items, train.Count, sparsity);
if (train is ITimedRatings)
{
var time_train = train as ITimedRatings;
s += string.Format(CultureInfo.InvariantCulture, "rating period: {0} to {1}\n", time_train.EarliestTime, time_train.LatestTime);
}
// test data stats
if (test != null)
{
num_users = test.AllUsers.Count;
num_items = test.AllItems.Count;
matrix_size = (long)num_users * num_items;
empty_size = (long)matrix_size - test.Count; // TODO depends on the eval scheme whether this is correct
sparsity = (double)100L * empty_size / matrix_size;
s += string.Format(CultureInfo.InvariantCulture, "test data: {0} users, {1} items, {2} ratings, sparsity {3,0:0.#####}\n", num_users, num_items, test.Count, sparsity);
if (test is ITimedRatings)
{
var time_test = test as ITimedRatings;
s += string.Format(CultureInfo.InvariantCulture, "rating period: {0} to {1}\n", time_test.EarliestTime, time_test.LatestTime);
}
}
// count and display the overlap between train and test
if (display_overlap && test != null)
{
int num_new_users = 0;
int num_new_items = 0;
TimeSpan seconds = Wrap.MeasureTime(delegate() {
num_new_users = test.AllUsers.Except(train.AllUsers).Count();
num_new_items = test.AllItems.Except(train.AllItems).Count();
});
s += string.Format("{0} new users, {1} new items ({2} seconds)\n", num_new_users, num_new_items, seconds);
}
return(s + Statistics(user_attributes, item_attributes));
}
/// <summary>Optimizes the specified data</summary>
/// <param name="data">data</param>
/// <param name="W">W</param>
/// <param name="H">H</param>
protected virtual void Optimize(IBooleanMatrix data, Matrix <float> W, Matrix <float> H)
{
// comments are in terms of computing the user factors
// ... works the same with users and items exchanged
// (1) create HH in O(f^2|Items|)
var HH = ComputeSquareMatrix(H);
// (2) optimize all U
Parallel.For(
0,
W.dim1,
u => { Optimize(u, data, W, H, HH); }
);
}
///
public void ComputeCorrelations(IBooleanMatrix entity_data)
{
Resize(entity_data.NumberOfRows);
// the diagonal of the correlation matrix
for (int i = 0; i < NumEntities; i++)
this[i, i] = 1;
if (Weighted)
ComputeCorrelationsWeighted(entity_data);
else if (entity_data.NumberOfColumns > ushort.MaxValue) // if possible, save some memory
ComputeCorrelationsUIntOverlap(entity_data);
else
ComputeCorrelationsUShortOverlap(entity_data);
}
/// <summary>Display dataset statistics</summary>
/// <param name="train">the training data</param>
/// <param name="test">the test data</param>
/// <param name="user_attributes">the user attributes</param>
/// <param name="item_attributes">the item attributes</param>
/// <param name="display_overlap">if set true, display the user/item overlap between train and test</param>
public static string Statistics(
this IRatings train, IRatings test = null,
IBooleanMatrix user_attributes = null, IBooleanMatrix item_attributes = null,
bool display_overlap = false)
{
// training data stats
int num_users = train.AllUsers.Count;
int num_items = train.AllItems.Count;
long matrix_size = (long) num_users * num_items;
long empty_size = (long) matrix_size - train.Count;
double sparsity = (double) 100L * empty_size / matrix_size;
string s = string.Format(CultureInfo.InvariantCulture, "training data: {0} users, {1} items, {2} ratings, sparsity {3,0:0.#####}\n", num_users, num_items, train.Count, sparsity);
if (train is ITimedRatings)
{
var time_train = train as ITimedRatings;
s += string.Format(CultureInfo.InvariantCulture, "rating period: {0} to {1}\n", time_train.EarliestTime, time_train.LatestTime);
}
// test data stats
if (test != null)
{
num_users = test.AllUsers.Count;
num_items = test.AllItems.Count;
matrix_size = (long) num_users * num_items;
empty_size = (long) matrix_size - test.Count; // TODO depends on the eval scheme whether this is correct
sparsity = (double) 100L * empty_size / matrix_size;
s += string.Format(CultureInfo.InvariantCulture, "test data: {0} users, {1} items, {2} ratings, sparsity {3,0:0.#####}\n", num_users, num_items, test.Count, sparsity);
if (test is ITimedRatings)
{
var time_test = test as ITimedRatings;
s += string.Format(CultureInfo.InvariantCulture, "rating period: {0} to {1}\n", time_test.EarliestTime, time_test.LatestTime);
}
}
// count and display the overlap between train and test
if (display_overlap && test != null)
{
int num_new_users = 0;
int num_new_items = 0;
TimeSpan seconds = Wrap.MeasureTime(delegate() {
num_new_users = test.AllUsers.Except(train.AllUsers).Count();
num_new_items = test.AllItems.Except(train.AllItems).Count();
});
s += string.Format("{0} new users, {1} new items ({2} seconds)\n", num_new_users, num_new_items, seconds);
}
return s + Statistics(user_attributes, item_attributes);
}
/// <summary>Creates a Cosine similarity matrix from given data</summary>
/// <param name="vectors">the boolean data</param>
/// <returns>the similarity matrix based on the data</returns>
public static CorrelationMatrix Create(IBooleanMatrix vectors)
{
BinaryDataCorrelationMatrix cm;
int num_entities = vectors.NumberOfRows;
try
{
cm = new WeightedBinaryCosine(num_entities);
}
catch (OverflowException)
{
Console.Error.WriteLine("Too many entities: " + num_entities);
throw;
}
cm.ComputeCorrelations(vectors);
return cm;
}
///
public override void ComputeCorrelations(IBooleanMatrix entity_data)
{
var transpose = entity_data.Transpose();
var overlap = new SparseMatrix <int>(entity_data.NumberOfRows, entity_data.NumberOfRows);
// go over all (other) entities
for (int row_id = 0; row_id < transpose.NumberOfRows; row_id++)
{
var row = ((IBooleanMatrix)transpose).GetEntriesByRow(row_id);
for (int i = 0; i < row.Count; i++)
{
int x = row[i];
for (int j = i + 1; j < row.Count; j++)
{
int y = row[j];
if (x < y)
{
overlap[x, y]++;
}
else
{
overlap[y, x]++;
}
}
}
}
// the diagonal of the correlation matrix
for (int i = 0; i < num_entities; i++)
{
this[i, i] = 1;
}
// compute cosine
foreach (var index_pair in overlap.NonEmptyEntryIDs)
{
int x = index_pair.First;
int y = index_pair.Second;
this[x, y] = (float)(overlap[x, y] / Math.Sqrt(entity_data.NumEntriesByRow(x) * entity_data.NumEntriesByRow(y)));
}
}
/// <summary>Get the overlap of two matrices, i.e. the number of true entries where they agree</summary>
/// <param name="s">the <see cref="SparseBooleanMatrix"/> to compare to</param>
/// <returns>the number of entries that are true in both matrices</returns>
public int Overlap(IBooleanMatrix s)
{
int c = 0;
for (int i = 0; i < row_list.Count; i++)
{
foreach (int j in row_list[i])
{
if (s[i, j])
{
c++;
}
}
}
return(c);
}
/// <summary>Creates a Cosine similarity matrix from given data</summary>
/// <param name="vectors">the boolean data</param>
/// <returns>the similarity matrix based on the data</returns>
static public CorrelationMatrix Create(IBooleanMatrix vectors)
{
BinaryDataCorrelationMatrix cm;
int num_entities = vectors.NumberOfRows;
try
{
cm = new BinaryCosine(num_entities);
}
catch (OverflowException)
{
Console.Error.WriteLine("Too many entities: " + num_entities);
throw;
}
cm.ComputeCorrelations(vectors);
return(cm);
}
/// <summary>Compute the overlap between the vectors in a binary matrix</summary>
/// <returns>a sparse matrix with the overlaps</returns>
/// <param name='entity_data'>the binary matrix</param>
public static IMatrix<uint> ComputeUInt(IBooleanMatrix entity_data)
{
var transpose = entity_data.Transpose() as IBooleanMatrix;
var overlap = new SymmetricSparseMatrix<uint>(entity_data.NumberOfRows);
// go over all (other) entities
for (int row_id = 0; row_id < transpose.NumberOfRows; row_id++)
{
var row = transpose.GetEntriesByRow(row_id);
for (int i = 0; i < row.Count; i++)
{
int x = row[i];
for (int j = i + 1; j < row.Count; j++)
overlap[x, row[j]]++;
}
}
return overlap;
}
protected virtual void LoadData()
{
training_file = Path.Combine(data_dir, training_file);
if (test_file != null)
{
test_file = Path.Combine(data_dir, test_file);
}
// user attributes
if (user_attributes_file != null)
{
user_attributes = AttributeData.Read(Path.Combine(data_dir, user_attributes_file), user_mapping);
}
if (recommender is IUserAttributeAwareRecommender)
{
((IUserAttributeAwareRecommender)recommender).UserAttributes = user_attributes;
}
// item attributes
if (item_attributes_file != null)
{
item_attributes = AttributeData.Read(Path.Combine(data_dir, item_attributes_file), item_mapping);
}
if (recommender is IItemAttributeAwareRecommender)
{
((IItemAttributeAwareRecommender)recommender).ItemAttributes = item_attributes;
}
// user relation
if (recommender is IUserRelationAwareRecommender)
{
((IUserRelationAwareRecommender)recommender).UserRelation = RelationData.Read(Path.Combine(data_dir, user_relations_file), user_mapping);
Console.WriteLine("relation over {0} users", ((IUserRelationAwareRecommender)recommender).NumUsers);
}
// item relation
if (recommender is IItemRelationAwareRecommender)
{
((IItemRelationAwareRecommender)recommender).ItemRelation = RelationData.Read(Path.Combine(data_dir, item_relations_file), item_mapping);
Console.WriteLine("relation over {0} items", ((IItemRelationAwareRecommender)recommender).NumItems);
}
}
/// <summary>Display statistics for user and item attributes</summary>
/// <param name="user_attributes">the user attributes</param>
/// <param name="item_attributes">the item attributes</param>
public static string Statistics(IBooleanMatrix user_attributes, IBooleanMatrix item_attributes)
{
string s = string.Empty;
if (user_attributes != null)
{
s += string.Format(
"{0} user attributes for {1} users, {2} assignments, {3} users with attribute assignments\n",
user_attributes.NumberOfColumns, user_attributes.NumberOfRows,
user_attributes.NumberOfEntries, user_attributes.NonEmptyRowIDs.Count);
}
if (item_attributes != null)
{
s += string.Format(
"{0} item attributes for {1} items, {2} assignments, {3} items with attribute assignments\n",
item_attributes.NonEmptyColumnIDs.Count, item_attributes.NumberOfRows,
item_attributes.NumberOfEntries, item_attributes.NonEmptyRowIDs.Count);
}
return(s);
}
/// <summary>Computes the overlap between the vectors in a binary matrix</summary>
/// <returns>a sparse matrix with the overlaps</returns>
/// <param name='entity_data'>the binary matrix</param>
public static IMatrix <ushort> ComputeUShort(IBooleanMatrix entity_data)
{
var transpose = entity_data.Transpose() as IBooleanMatrix;
var overlap = new SymmetricSparseMatrix <ushort>(entity_data.NumberOfRows);
// go over all (other) entities
for (int row_id = 0; row_id < transpose.NumberOfRows; row_id++)
{
var row = transpose.GetEntriesByRow(row_id);
for (int i = 0; i < row.Count; i++)
{
int x = row[i];
for (int j = i + 1; j < row.Count; j++)
{
overlap[x, row[j]]++;
}
}
}
return(overlap);
}
///
public void ComputeCorrelations(IBooleanMatrix entity_data)
{
Resize(entity_data.NumberOfRows);
// the diagonal of the correlation matrix
for (int i = 0; i < NumEntities; i++)
{
this[i, i] = 1;
}
if (Weighted)
{
ComputeCorrelationsWeighted(entity_data);
}
else if (entity_data.NumberOfColumns > ushort.MaxValue) // if possible, save some memory
{
ComputeCorrelationsUIntOverlap(entity_data);
}
else
{
ComputeCorrelationsUShortOverlap(entity_data);
}
}
///
public override void ComputeCorrelations(IBooleanMatrix entity_data)
{
var transpose = entity_data.Transpose() as IBooleanMatrix;
var overlap = new SymmetricMatrix<int>(entity_data.NumberOfRows);
// go over all (other) entities
for (int row_id = 0; row_id < transpose.NumberOfRows; row_id++)
{
var row = transpose.GetEntriesByRow(row_id);
for (int i = 0; i < row.Count; i++)
{
int x = row[i];
for (int j = i + 1; j < row.Count; j++)
{
int y = row[j];
overlap[x, y]++;
}
}
}
// the diagonal of the correlation matrix
for (int i = 0; i < num_entities; i++)
this[i, i] = 1;
// compute Jaccard index
for (int x = 0; x < num_entities; x++)
for (int y = 0; y < x; y++)
this[x, y] = (float) (overlap[x, y] / (entity_data.NumEntriesByRow(x) + entity_data.NumEntriesByRow(y) - overlap[x, y]));
}
///
protected internal override void InitModel()
{
base.InitModel();
if (user_connections == null)
{
user_connections = new SparseBooleanMatrix();
Console.Error.WriteLine("Warning: UserRelation not set.");
}
group = new float[user_connections.NumberOfEntries];
}
/// <summary>Compute the correlations from an implicit feedback, positive-only dataset</summary>
/// <param name="entity_data">the implicit feedback set, rows contain the entities to correlate</param>
public virtual void ComputeCorrelations(IBooleanMatrix entity_data)
{
throw new NotSupportedException();
}
/// <summary>Optimizes the specified data</summary>
/// <param name="data">data</param>
/// <param name="W">W</param>
/// <param name="H">H</param>
protected virtual void Optimize(IBooleanMatrix data, Matrix <float> W, Matrix <float> H)
{
var HH = new Matrix <double>(num_factors, num_factors);
// comments are in terms of computing the user factors
// ... works the same with users and items exchanged
// (1) create HH in O(f^2|Items|)
// HH is symmetric
for (int f_1 = 0; f_1 < num_factors; f_1++)
{
for (int f_2 = 0; f_2 < num_factors; f_2++)
{
double d = 0;
for (int i = 0; i < H.dim1; i++)
{
d += H[i, f_1] * H[i, f_2];
}
HH[f_1, f_2] = d;
}
}
// (2) optimize all U
// HC_minus_IH is symmetric
Parallel.For(0, W.dim1, u =>
{
var row = data.GetEntriesByRow(u);
// create HC_minus_IH in O(f^2|S_u|)
var HC_minus_IH = new Matrix <double>(num_factors, num_factors);
for (int f_1 = 0; f_1 < num_factors; f_1++)
{
for (int f_2 = 0; f_2 < num_factors; f_2++)
{
double d = 0;
foreach (int i in row)
{
d += H[i, f_1] * H[i, f_2] * alpha;
}
HC_minus_IH[f_1, f_2] = d;
}
}
// create HCp in O(f|S_u|)
var HCp = new double[num_factors];
for (int f = 0; f < num_factors; f++)
{
double d = 0;
foreach (int i in row)
{
d += H[i, f] * (1 + alpha);
}
HCp[f] = d;
}
// create m = HH + HC_minus_IH + reg*I
// m is symmetric
// the inverse m_inv is symmetric
var m = new DenseMatrix(num_factors, num_factors);
for (int f_1 = 0; f_1 < num_factors; f_1++)
{
for (int f_2 = 0; f_2 < num_factors; f_2++)
{
double d = HH[f_1, f_2] + HC_minus_IH[f_1, f_2];
if (f_1 == f_2)
{
d += regularization;
}
m[f_1, f_2] = d;
}
}
var m_inv = m.Inverse();
// write back optimal W
for (int f = 0; f < num_factors; f++)
{
double d = 0;
for (int f_2 = 0; f_2 < num_factors; f_2++)
{
d += m_inv[f, f_2] * HCp[f_2];
}
W[u, f] = (float)d;
}
});
}
/// <summary>Optimizes the specified data</summary>
/// <param name="data">data</param>
/// <param name="W">W</param>
/// <param name="H">H</param>
protected virtual void Optimize(IBooleanMatrix data, Matrix <double> W, Matrix <double> H)
{
var HH = new Matrix <double>(num_factors, num_factors);
var HC_minus_IH = new Matrix <double>(num_factors, num_factors);
var HCp = new double[num_factors];
var m = new MathNet.Numerics.LinearAlgebra.Matrix(num_factors, num_factors);
MathNet.Numerics.LinearAlgebra.Matrix m_inv;
// TODO speed up using more parts of that library
// source code comments are in terms of computing the user factors
// works the same with users and items exchanged
// (1) create HH in O(f^2|Items|)
// HH is symmetric
for (int f_1 = 0; f_1 < num_factors; f_1++)
{
for (int f_2 = 0; f_2 < num_factors; f_2++)
{
double d = 0;
for (int i = 0; i < H.dim1; i++)
{
d += H[i, f_1] * H[i, f_2];
}
HH[f_1, f_2] = d;
}
}
// (2) optimize all U
// HC_minus_IH is symmetric
for (int u = 0; u < W.dim1; u++)
{
var row = data.GetEntriesByRow(u);
// create HC_minus_IH in O(f^2|S_u|)
for (int f_1 = 0; f_1 < num_factors; f_1++)
{
for (int f_2 = 0; f_2 < num_factors; f_2++)
{
double d = 0;
foreach (int i in row)
{
//d += H[i, f_1] * H[i, f_2] * (c_pos - 1);
d += H[i, f_1] * H[i, f_2] * c_pos;
}
HC_minus_IH[f_1, f_2] = d;
}
}
// create HCp in O(f|S_u|)
for (int f = 0; f < num_factors; f++)
{
double d = 0;
foreach (int i in row)
{
//d += H[i, f] * c_pos;
d += H[i, f] * (1 + c_pos);
}
HCp[f] = d;
}
// create m = HH + HC_minus_IH + reg*I
// m is symmetric
// the inverse m_inv is symmetric
for (int f_1 = 0; f_1 < num_factors; f_1++)
{
for (int f_2 = 0; f_2 < num_factors; f_2++)
{
double d = HH[f_1, f_2] + HC_minus_IH[f_1, f_2];
if (f_1 == f_2)
{
d += regularization;
}
m[f_1, f_2] = d;
}
}
m_inv = m.Inverse();
// write back optimal W
for (int f = 0; f < num_factors; f++)
{
double d = 0;
for (int f_2 = 0; f_2 < num_factors; f_2++)
{
d += m_inv[f, f_2] * HCp[f_2];
}
W[u, f] = d;
}
}
}
/// <summary>Optimizes the specified data</summary>
/// <param name="data">data</param>
/// <param name="inverse_data">data</param>
/// <param name="W">W</param>
/// <param name="H">H</param>
void Optimize(IBooleanMatrix data, IBooleanMatrix inverse_data, Matrix<double> W, Matrix<double> H)
{
var HH = new Matrix<double>(num_factors, num_factors);
var HC_minus_IH = new Matrix<double>(num_factors, num_factors);
var HCp = new double[num_factors];
var m = new MathNet.Numerics.LinearAlgebra.Matrix(num_factors, num_factors);
MathNet.Numerics.LinearAlgebra.Matrix m_inv;
// TODO speed up using more parts of that library
// TODO using properties gives a 3-5% performance penalty
// source code comments are in terms of computing the user factors
// works the same with users and items exchanged
// (1) create HH in O(f^2|Items|)
// HH is symmetric
for (int f_1 = 0; f_1 < num_factors; f_1++)
for (int f_2 = 0; f_2 < num_factors; f_2++)
{
double d = 0;
for (int i = 0; i < H.dim1; i++)
d += H[i, f_1] * H[i, f_2];
HH[f_1, f_2] = d;
}
// (2) optimize all U
// HC_minus_IH is symmetric
for (int u = 0; u < W.dim1; u++)
{
var row = data.GetEntriesByRow(u);
// prepare KDD Cup specific weighting
int num_user_items = row.Count;
int user_positive_weight_sum = 0;
foreach (int i in row)
user_positive_weight_sum += inverse_data.NumEntriesByRow(i);
double neg_weight_normalization = (double) (num_user_items * (1 + CPos)) / (Feedback.Count - user_positive_weight_sum);
// TODO precompute
// TODO check whether this is correct
// create HC_minus_IH in O(f^2|S_u|)
for (int f_1 = 0; f_1 < num_factors; f_1++)
for (int f_2 = 0; f_2 < num_factors; f_2++)
{
double d = 0;
foreach (int i in row)
//d += H[i, f_1] * H[i, f_2] * (c_pos - 1);
d += H[i, f_1] * H[i, f_2] * CPos;
HC_minus_IH[f_1, f_2] = d;
}
// create HCp in O(f|S_u|)
for (int f = 0; f < num_factors; f++)
{
double d = 0;
for (int i = 0; i < inverse_data.NumberOfRows; i++)
if (row.Contains(i))
d += H[i, f] * (1 + CPos);
else
d += H[i, f] * inverse_data.NumEntriesByRow(i) * neg_weight_normalization;
HCp[f] = d;
}
// create m = HH + HC_minus_IH + reg*I
// m is symmetric
// the inverse m_inv is symmetric
for (int f_1 = 0; f_1 < num_factors; f_1++)
for (int f_2 = 0; f_2 < num_factors; f_2++)
{
double d = HH[f_1, f_2] + HC_minus_IH[f_1, f_2];
if (f_1 == f_2)
d += Regularization;
m[f_1, f_2] = d;
}
m_inv = m.Inverse();
// write back optimal W
for (int f = 0; f < num_factors; f++)
{
double d = 0;
for (int f_2 = 0; f_2 < num_factors; f_2++)
d += m_inv[f, f_2] * HCp[f_2];
W[u, f] = d;
}
}
}
/// <summary>Compute the correlations from an implicit feedback, positive-only dataset</summary>
/// <param name="entity_data">the implicit feedback set, rows contain the entities to correlate</param>
public virtual void ComputeCorrelations(IBooleanMatrix entity_data)
{
throw new NotSupportedException();
}
/// <summary>Compute the correlations from an implicit feedback, positive-only dataset</summary> /// <param name="entity_data">the implicit feedback set, rows contain the entities to correlate</param> public abstract void ComputeCorrelations(IBooleanMatrix entity_data);
///
public override void ComputeCorrelations(IBooleanMatrix entity_data)
{
// if possible, save some memory
if (entity_data.NumberOfColumns > ushort.MaxValue)
ComputeCorrelationsUIntOverlap(entity_data);
else
ComputeCorrelationsUShortOverlap(entity_data);
}
private void Optimize(int u, IBooleanMatrix data, Matrix <float> W, Matrix <float> H, Matrix <double> HH)
{
var row = data.GetEntriesByRow(u);
// HC_minus_IH is symmetric
// create HC_minus_IH in O(f^2|S_u|)
var HC_minus_IH = new Matrix <double>(num_factors, num_factors);
for (int f_1 = 0; f_1 < num_factors; f_1++)
{
for (int f_2 = f_1; f_2 < num_factors; f_2++)
{
double d = 0;
foreach (int i in row)
{
d += H[i, f_1] * H[i, f_2];
}
HC_minus_IH[f_1, f_2] = d * Alpha;
HC_minus_IH[f_2, f_1] = d * Alpha;
}
}
// create HCp in O(f|S_u|)
var HCp = new double[num_factors];
for (int f = 0; f < num_factors; f++)
{
double d = 0;
foreach (int i in row)
{
d += H[i, f];
}
HCp[f] = d * (1 + Alpha);
}
// create m = HH + HC_minus_IH + reg*I
// m is symmetric
// the inverse m_inv is symmetric
var m = new DenseMatrix(num_factors, num_factors);
for (int f_1 = 0; f_1 < num_factors; f_1++)
{
for (int f_2 = f_1; f_2 < num_factors; f_2++)
{
double d = HH[f_1, f_2] + HC_minus_IH[f_1, f_2];
if (f_1 == f_2)
{
d += Regularization;
}
m[f_1, f_2] = d;
m[f_2, f_1] = d;
}
}
var m_inv = m.Inverse();
// write back optimal W
for (int f = 0; f < num_factors; f++)
{
double d = 0;
for (int f_2 = 0; f_2 < num_factors; f_2++)
{
d += m_inv[f, f_2] * HCp[f_2];
}
W[u, f] = (float)d;
}
}
///
public override void ComputeCorrelations(IBooleanMatrix entity_data)
{
var transpose = (IBooleanMatrix) entity_data.Transpose();
var other_entity_weights = new float[transpose.NumberOfRows];
for (int row_id = 0; row_id < transpose.NumberOfRows; row_id++)
{
int freq = transpose.GetEntriesByRow(row_id).Count;
other_entity_weights[row_id] = 1f / (float) Math.Log(3 + freq, 2); // TODO make configurable
}
var weighted_overlap = new SymmetricMatrix<float>(entity_data.NumberOfRows);
var entity_weights = new float[entity_data.NumberOfRows];
// go over all (other) entities
for (int row_id = 0; row_id < transpose.NumberOfRows; row_id++)
{
var row = transpose.GetEntriesByRow(row_id);
for (int i = 0; i < row.Count; i++)
{
int x = row[i];
entity_weights[x] += other_entity_weights[row_id];
for (int j = i + 1; j < row.Count; j++)
{
int y = row[j];
weighted_overlap[x, y] += other_entity_weights[row_id] * other_entity_weights[row_id];
}
}
}
// the diagonal of the correlation matrix
for (int i = 0; i < num_entities; i++)
this[i, i] = 1;
// compute cosine
for (int x = 0; x < num_entities; x++)
for (int y = 0; y < x; y++)
this[x, y] = (float) (weighted_overlap[x, y] / Math.Sqrt(entity_weights[x] * entity_weights[y] ));
}
///
public int Overlap(IBooleanMatrix s)
{
int c = 0;
for (int i = 0; i < row_list.Count; i++)
foreach (int j in row_list[i])
if (s[i, j])
c++;
return c;
}
void ComputeCorrelationsUShortOverlap(IBooleanMatrix entity_data)
{
var transpose = entity_data.Transpose() as IBooleanMatrix;
var overlap = new SymmetricMatrix<ushort>(entity_data.NumberOfRows);
// go over all (other) entities
for (int row_id = 0; row_id < transpose.NumberOfRows; row_id++)
{
var row = transpose.GetEntriesByRow(row_id);
for (int i = 0; i < row.Count; i++)
{
int x = row[i];
for (int j = i + 1; j < row.Count; j++)
overlap[x, row[j]]++;
}
}
// the diagonal of the correlation matrix
for (int i = 0; i < num_entities; i++)
this[i, i] = 1;
// compute cosine
for (int x = 0; x < num_entities; x++)
for (int y = 0; y < x; y++)
{
long size_product = entity_data.NumEntriesByRow(x) * entity_data.NumEntriesByRow(y);
if (size_product > 0)
this[x, y] = (float) (overlap[x, y] / Math.Sqrt(size_product));
}
}
private void Optimize(int u, IBooleanMatrix data, Matrix<float> W, Matrix<float> H, Matrix<double> HH)
{
var row = data.GetEntriesByRow(u);
// HC_minus_IH is symmetric
// create HC_minus_IH in O(f^2|S_u|)
var HC_minus_IH = new Matrix<double>(num_factors, num_factors);
for (int f_1 = 0; f_1 < num_factors; f_1++)
for (int f_2 = f_1; f_2 < num_factors; f_2++)
{
double d = 0;
foreach (int i in row)
d += H[i, f_1] * H[i, f_2];
HC_minus_IH[f_1, f_2] = d * alpha;
HC_minus_IH[f_2, f_1] = d * alpha;
}
// create HCp in O(f|S_u|)
var HCp = new double[num_factors];
for (int f = 0; f < num_factors; f++)
{
double d = 0;
foreach (int i in row)
d += H[i, f];
HCp[f] = d * (1 + alpha);
}
// create m = HH + HC_minus_IH + reg*I
// m is symmetric
// the inverse m_inv is symmetric
var m = new DenseMatrix(num_factors, num_factors);
for (int f_1 = 0; f_1 < num_factors; f_1++)
for (int f_2 = f_1; f_2 < num_factors; f_2++)
{
double d = HH[f_1, f_2] + HC_minus_IH[f_1, f_2];
if (f_1 == f_2)
d += regularization;
m[f_1, f_2] = d;
m[f_2, f_1] = d;
}
var m_inv = m.Inverse();
// write back optimal W
for (int f = 0; f < num_factors; f++)
{
double d = 0;
for (int f_2 = 0; f_2 < num_factors; f_2++)
d += m_inv[f, f_2] * HCp[f_2];
W[u, f] = (float) d;
}
}
/// <summary>Display statistics for user and item attributes</summary>
/// <param name="user_attributes">the user attributes</param>
/// <param name="item_attributes">the item attributes</param>
public static string Statistics(IBooleanMatrix user_attributes, IBooleanMatrix item_attributes)
{
string s = string.Empty;
if (user_attributes != null)
{
s += string.Format(
"{0} user attributes for {1} users, {2} assignments, {3} users with attribute assignments\n",
user_attributes.NumberOfColumns, user_attributes.NumberOfRows,
user_attributes.NumberOfEntries, user_attributes.NonEmptyRowIDs.Count);
}
if (item_attributes != null)
s += string.Format(
"{0} item attributes for {1} items, {2} assignments, {3} items with attribute assignments\n",
item_attributes.NonEmptyColumnIDs.Count, item_attributes.NumberOfRows,
item_attributes.NumberOfEntries, item_attributes.NonEmptyRowIDs.Count);
return s;
}
///
public override void ComputeCorrelations(IBooleanMatrix entity_data)
{
var transpose = entity_data.Transpose();
var overlap = new SparseMatrix<int>(entity_data.NumberOfRows, entity_data.NumberOfRows);
// go over all (other) entities
for (int row_id = 0; row_id < transpose.NumberOfRows; row_id++)
{
var row = ((IBooleanMatrix) transpose).GetEntriesByRow(row_id);
for (int i = 0; i < row.Count; i++)
{
int x = row[i];
for (int j = i + 1; j < row.Count; j++)
{
int y = row[j];
if (x < y)
overlap[x, y]++;
else
overlap[y, x]++;
}
}
}
// the diagonal of the correlation matrix
for (int i = 0; i < num_entities; i++)
this[i, i] = 1;
// compute cosine
foreach (var index_pair in overlap.NonEmptyEntryIDs)
{
int x = index_pair.First;
int y = index_pair.Second;
this[x, y] = (float) (overlap[x, y] / Math.Sqrt(entity_data.NumEntriesByRow(x) * entity_data.NumEntriesByRow(y) ));
}
}
/// <summary>Display data statistics for item recommendation datasets</summary>
/// <param name="training_data">the training dataset</param>
/// <param name="test_data">the test dataset</param>
/// <param name="user_attributes">the user attributes</param>
/// <param name="item_attributes">the item attributes</param>
public static string Statistics(
this IPosOnlyFeedback training_data, IPosOnlyFeedback test_data = null,
IBooleanMatrix user_attributes = null, IBooleanMatrix item_attributes = null)
{
// training data stats
int num_users = training_data.AllUsers.Count;
int num_items = training_data.AllItems.Count;
long matrix_size = (long) num_users * num_items;
long empty_size = (long) matrix_size - training_data.Count;
double sparsity = (double) 100L * empty_size / matrix_size;
string s = string.Format(CultureInfo.InvariantCulture, "training data: {0} users, {1} items, {2} events, sparsity {3,0:0.#####}\n", num_users, num_items, training_data.Count, sparsity);
// test data stats
if (test_data != null)
{
num_users = test_data.AllUsers.Count;
num_items = test_data.AllItems.Count;
matrix_size = (long) num_users * num_items;
empty_size = (long) matrix_size - test_data.Count;
sparsity = (double) 100L * empty_size / matrix_size; // TODO depends on the eval scheme whether this is correct
s += string.Format(CultureInfo.InvariantCulture, "test data: {0} users, {1} items, {2} events, sparsity {3,0:0.#####}\n", num_users, num_items, test_data.Count, sparsity);
}
return s + Statistics(user_attributes, item_attributes);
}
/// <summary>Optimizes the specified data</summary>
/// <param name="data">data</param>
/// <param name="W">W</param>
/// <param name="H">H</param>
protected virtual void Optimize(IBooleanMatrix data, Matrix<float> W, Matrix<float> H)
{
var HH = new Matrix<double>(num_factors, num_factors);
var HC_minus_IH = new Matrix<double>(num_factors, num_factors);
var HCp = new double[num_factors];
var m = new DenseMatrix(num_factors, num_factors);
// source code comments are in terms of computing the user factors
// works the same with users and items exchanged
// (1) create HH in O(f^2|Items|)
// HH is symmetric
for (int f_1 = 0; f_1 < num_factors; f_1++)
for (int f_2 = 0; f_2 < num_factors; f_2++)
{
double d = 0;
for (int i = 0; i < H.dim1; i++)
d += H[i, f_1] * H[i, f_2];
HH[f_1, f_2] = d;
}
// (2) optimize all U
// HC_minus_IH is symmetric
for (int u = 0; u < W.dim1; u++)
{
var row = data.GetEntriesByRow(u);
// create HC_minus_IH in O(f^2|S_u|)
for (int f_1 = 0; f_1 < num_factors; f_1++)
for (int f_2 = 0; f_2 < num_factors; f_2++)
{
double d = 0;
foreach (int i in row)
//d += H[i, f_1] * H[i, f_2] * (c_pos - 1);
d += H[i, f_1] * H[i, f_2] * c_pos;
HC_minus_IH[f_1, f_2] = d;
}
// create HCp in O(f|S_u|)
for (int f = 0; f < num_factors; f++)
{
double d = 0;
foreach (int i in row)
//d += H[i, f] * c_pos;
d += H[i, f] * (1 + c_pos);
HCp[f] = d;
}
// create m = HH + HC_minus_IH + reg*I
// m is symmetric
// the inverse m_inv is symmetric
for (int f_1 = 0; f_1 < num_factors; f_1++)
for (int f_2 = 0; f_2 < num_factors; f_2++)
{
double d = HH[f_1, f_2] + HC_minus_IH[f_1, f_2];
if (f_1 == f_2)
d += regularization;
m[f_1, f_2] = d;
}
var m_inv = m.Inverse();
// write back optimal W
for (int f = 0; f < num_factors; f++)
{
double d = 0;
for (int f_2 = 0; f_2 < num_factors; f_2++)
d += m_inv[f, f_2] * HCp[f_2];
W[u, f] = (float) d;
}
}
}
/// <summary>Optimizes the specified data</summary>
/// <param name="data">data</param>
/// <param name="inverse_data">data</param>
/// <param name="W">W</param>
/// <param name="H">H</param>
void Optimize(IBooleanMatrix data, IBooleanMatrix inverse_data, Matrix <double> W, Matrix <double> H)
{
var HH = new Matrix <double>(num_factors, num_factors);
var HC_minus_IH = new Matrix <double>(num_factors, num_factors);
var HCp = new double[num_factors];
var m = new MathNet.Numerics.LinearAlgebra.Matrix(num_factors, num_factors);
MathNet.Numerics.LinearAlgebra.Matrix m_inv;
// TODO speed up using more parts of that library
// TODO using properties gives a 3-5% performance penalty
// source code comments are in terms of computing the user factors
// works the same with users and items exchanged
// (1) create HH in O(f^2|Items|)
// HH is symmetric
for (int f_1 = 0; f_1 < num_factors; f_1++)
{
for (int f_2 = 0; f_2 < num_factors; f_2++)
{
double d = 0;
for (int i = 0; i < H.dim1; i++)
{
d += H[i, f_1] * H[i, f_2];
}
HH[f_1, f_2] = d;
}
}
// (2) optimize all U
// HC_minus_IH is symmetric
for (int u = 0; u < W.dim1; u++)
{
var row = data.GetEntriesByRow(u);
// prepare KDD Cup specific weighting
int num_user_items = row.Count;
int user_positive_weight_sum = 0;
foreach (int i in row)
{
user_positive_weight_sum += inverse_data.NumEntriesByRow(i);
}
double neg_weight_normalization = (double)(num_user_items * (1 + CPos)) / (Feedback.Count - user_positive_weight_sum);
// TODO precompute
// TODO check whether this is correct
// create HC_minus_IH in O(f^2|S_u|)
for (int f_1 = 0; f_1 < num_factors; f_1++)
{
for (int f_2 = 0; f_2 < num_factors; f_2++)
{
double d = 0;
foreach (int i in row)
{
//d += H[i, f_1] * H[i, f_2] * (c_pos - 1);
d += H[i, f_1] * H[i, f_2] * CPos;
}
HC_minus_IH[f_1, f_2] = d;
}
}
// create HCp in O(f|S_u|)
for (int f = 0; f < num_factors; f++)
{
double d = 0;
for (int i = 0; i < inverse_data.NumberOfRows; i++)
{
if (row.Contains(i))
{
d += H[i, f] * (1 + CPos);
}
else
{
d += H[i, f] * inverse_data.NumEntriesByRow(i) * neg_weight_normalization;
}
}
HCp[f] = d;
}
// create m = HH + HC_minus_IH + reg*I
// m is symmetric
// the inverse m_inv is symmetric
for (int f_1 = 0; f_1 < num_factors; f_1++)
{
for (int f_2 = 0; f_2 < num_factors; f_2++)
{
double d = HH[f_1, f_2] + HC_minus_IH[f_1, f_2];
if (f_1 == f_2)
{
d += Regularization;
}
m[f_1, f_2] = d;
}
}
m_inv = m.Inverse();
// write back optimal W
for (int f = 0; f < num_factors; f++)
{
double d = 0;
for (int f_2 = 0; f_2 < num_factors; f_2++)
{
d += m_inv[f, f_2] * HCp[f_2];
}
W[u, f] = d;
}
}
}
/// <summary>Evaluation for rankings of items recommended to groups</summary>
/// <remarks>
/// </remarks>
/// <param name="recommender">group recommender</param>
/// <param name="test">test cases</param>
/// <param name="train">training data</param>
/// <param name="group_to_user">group to user relation</param>
/// <param name="candidate_items">a collection of integers with all candidate items</param>
/// <param name="ignore_overlap">if true, ignore items that appear for a group in the training set when evaluating for that user</param>
/// <returns>a dictionary containing the evaluation results</returns>
public static ItemRecommendationEvaluationResults Evaluate(
this GroupRecommender recommender,
IPosOnlyFeedback test,
IPosOnlyFeedback train,
IBooleanMatrix group_to_user,
ICollection<int> candidate_items,
bool ignore_overlap = true)
{
var result = new ItemRecommendationEvaluationResults();
int num_groups = 0;
foreach (int group_id in group_to_user.NonEmptyRowIDs)
{
var users = group_to_user.GetEntriesByRow(group_id);
var correct_items = new HashSet<int>();
foreach (int user_id in users)
correct_items.UnionWith(test.UserMatrix[user_id]);
correct_items.IntersectWith(candidate_items);
var candidate_items_in_train = new HashSet<int>();
foreach (int user_id in users)
candidate_items_in_train.UnionWith(train.UserMatrix[user_id]);
candidate_items_in_train.IntersectWith(candidate_items);
int num_eval_items = candidate_items.Count - (ignore_overlap ? candidate_items_in_train.Count() : 0);
// skip all groups that have 0 or #candidate_items test items
if (correct_items.Count == 0)
continue;
if (num_eval_items - correct_items.Count == 0)
continue;
IList<int> prediction_list = recommender.RankItems(users, candidate_items);
if (prediction_list.Count != candidate_items.Count)
throw new Exception("Not all items have been ranked.");
var ignore_items = ignore_overlap ? candidate_items_in_train : new HashSet<int>();
double auc = AUC.Compute(prediction_list, correct_items, ignore_items);
double map = PrecisionAndRecall.AP(prediction_list, correct_items, ignore_items);
double ndcg = NDCG.Compute(prediction_list, correct_items, ignore_items);
double rr = ReciprocalRank.Compute(prediction_list, correct_items, ignore_items);
var positions = new int[] { 5, 10 };
var prec = PrecisionAndRecall.PrecisionAt(prediction_list, correct_items, ignore_items, positions);
var recall = PrecisionAndRecall.RecallAt(prediction_list, correct_items, ignore_items, positions);
// thread-safe incrementing
lock(result)
{
num_groups++;
result["AUC"] += (float) auc;
result["MAP"] += (float) map;
result["NDCG"] += (float) ndcg;
result["MRR"] += (float) rr;
result["prec@5"] += (float) prec[5];
result["prec@10"] += (float) prec[10];
result["recall@5"] += (float) recall[5];
result["recall@10"] += (float) recall[10];
}
if (num_groups % 1000 == 0)
Console.Error.Write(".");
if (num_groups % 60000 == 0)
Console.Error.WriteLine();
}
result["num_groups"] = num_groups;
result["num_lists"] = num_groups;
result["num_items"] = candidate_items.Count;
return result;
}