public static double[] ratingVector(PreferenceArray prefs)
{
double[] numArray = new double[prefs.length()];
for (int i = 0; i < prefs.length(); i++)
{
numArray[i] = prefs.get(i).getValue();
}
return(numArray);
}
private static double computeThreshold(PreferenceArray prefs)
{
if (prefs.length() < 2)
{
return(double.NegativeInfinity);
}
RunningAverageAndStdDev dev = new FullRunningAverageAndStdDev();
int num = prefs.length();
for (int i = 0; i < num; i++)
{
dev.addDatum((double)prefs.getValue(i));
}
return(dev.getAverage() + dev.getStandardDeviation());
}
public void removeItemPref(long userID, long itemIDA, float prefValue)
{
PreferenceArray userPreferences = dataModel.getPreferencesFromUser(userID);
try
{
buildAverageDiffsLock.EnterWriteLock();
FastByIDMap <RunningAverage> aMap = averageDiffs.get(itemIDA);
int length = userPreferences.length();
for (int i = 0; i < length; i++)
{
long itemIDB = userPreferences.getItemID(i);
float bValue = userPreferences.getValue(i);
if (itemIDA < itemIDB)
{
if (aMap != null)
{
RunningAverage average = aMap.get(itemIDB);
if (average != null)
{
if (average.getCount() <= 1)
{
aMap.remove(itemIDB);
}
else
{
average.removeDatum(bValue - prefValue);
}
}
}
}
else if (itemIDA > itemIDB)
{
FastByIDMap <RunningAverage> bMap = averageDiffs.get(itemIDB);
if (bMap != null)
{
RunningAverage average = bMap.get(itemIDA);
if (average != null)
{
if (average.getCount() <= 1)
{
aMap.remove(itemIDA);
}
else
{
average.removeDatum(prefValue - bValue);
}
}
}
}
}
}
finally
{
buildAverageDiffsLock.ExitWriteLock();
}
}
private static PreferenceArray cloneAndMergeInto(PreferenceArray delegatePrefs, long itemID, long newUserID, float value)
{
int num4;
int num = (delegatePrefs == null) ? 0 : delegatePrefs.length();
int size = num + 1;
PreferenceArray array = new GenericItemPreferenceArray(size);
array.setItemID(0, itemID);
int i = 0;
while ((i < num) && (newUserID > delegatePrefs.getUserID(i)))
{
i++;
}
for (num4 = 0; num4 < i; num4++)
{
array.setUserID(num4, delegatePrefs.getUserID(num4));
array.setValue(num4, delegatePrefs.getValue(num4));
}
array.setUserID(i, newUserID);
array.setValue(i, value);
for (num4 = i + 1; num4 < size; num4++)
{
array.setUserID(num4, delegatePrefs.getUserID(num4 - 1));
array.setValue(num4, delegatePrefs.getValue(num4 - 1));
}
return(array);
}
public RandomRecommender(DataModel dataModel)
: base(dataModel)
{
this.random = RandomUtils.getRandom();
float negativeInfinity = float.NegativeInfinity;
float positiveInfinity = float.PositiveInfinity;
IEnumerator <long> enumerator = dataModel.getUserIDs();
while (enumerator.MoveNext())
{
long current = enumerator.Current;
PreferenceArray array = dataModel.getPreferencesFromUser(current);
for (int i = 0; i < array.length(); i++)
{
float num5 = array.getValue(i);
if (num5 < positiveInfinity)
{
positiveInfinity = num5;
}
if (num5 > negativeInfinity)
{
negativeInfinity = num5;
}
}
}
this.minPref = positiveInfinity;
this.maxPref = negativeInfinity;
}
public void setTempPrefs(PreferenceArray prefs)
{
this.tempPrefs = prefs;
this.prefItemIDs.clear();
for (int i = 0; i < prefs.length(); i++)
{
this.prefItemIDs.add(prefs.getItemID(i));
}
}
private float doEstimatePreference(long userID, long itemID)
{
double count = 0.0;
double totalPreference = 0.0;
PreferenceArray prefs = getDataModel().getPreferencesFromUser(userID);
RunningAverage[] averages = diffStorage.getDiffs(userID, itemID, prefs);
int size = prefs.length();
for (int i = 0; i < size; i++)
{
RunningAverage averageDiff = averages[i];
if (averageDiff != null)
{
double averageDiffValue = averageDiff.getAverage();
if (weighted)
{
double weight = averageDiff.getCount();
if (stdDevWeighted)
{
var raaStdDev = averageDiff as RunningAverageAndStdDev;
if (raaStdDev != null)
{
double stdev = raaStdDev.getStandardDeviation();
if (!Double.IsNaN(stdev))
{
weight /= 1.0 + stdev;
}
}
// If stdev is NaN, then it is because count is 1. Because we're weighting by count,
// the weight is already relatively low. We effectively assume stdev is 0.0 here and
// that is reasonable enough. Otherwise, dividing by NaN would yield a weight of NaN
// and disqualify this pref entirely
// (Thanks Daemmon)
}
totalPreference += weight * (prefs.getValue(i) + averageDiffValue);
count += weight;
}
else
{
totalPreference += prefs.getValue(i) + averageDiffValue;
count += 1.0;
}
}
}
if (count <= 0.0)
{
RunningAverage itemAverage = diffStorage.getAverageItemPref(itemID);
return(itemAverage == null ? float.NaN : (float)itemAverage.getAverage());
}
else
{
return((float)(totalPreference / count));
}
}
protected IList <Tuple <int, double> > sparseUserRatingVector(PreferenceArray prefs)
{
List <Tuple <int, double> > list = new List <Tuple <int, double> >(prefs.length());
foreach (Preference preference in prefs)
{
list.Add(new Tuple <int, double>((int)preference.getItemID(), (double)preference.getValue()));
}
return(list);
}
public void setTempPrefs(PreferenceArray prefs, long anonymousUserID)
{
this.tempPrefs[anonymousUserID] = prefs;
FastIDSet set = new FastIDSet();
for (int i = 0; i < prefs.length(); i++)
{
set.add(prefs.getItemID(i));
}
this.prefItemIDs[anonymousUserID] = set;
}
public override FastIDSet getItemIDsFromUser(long userID)
{
PreferenceArray array = this.getPreferencesFromUser(userID);
int size = array.length();
FastIDSet set = new FastIDSet(size);
for (int i = 0; i < size; i++)
{
set.add(array.getItemID(i));
}
return(set);
}
private int countPreferences()
{
int num = 0;
IEnumerator <long> enumerator = this.dataModel.getUserIDs();
while (enumerator.MoveNext())
{
PreferenceArray array = this.dataModel.getPreferencesFromUser(enumerator.Current);
num += array.length();
}
return(num);
}
public void addItemPref(long userID, long itemIDA, float prefValue)
{
PreferenceArray userPreferences = dataModel.getPreferencesFromUser(userID);
try
{
buildAverageDiffsLock.EnterWriteLock();
FastByIDMap <RunningAverage> aMap = averageDiffs.get(itemIDA);
if (aMap == null)
{
aMap = new FastByIDMap <RunningAverage>();
averageDiffs.put(itemIDA, aMap);
}
int length = userPreferences.length();
for (int i = 0; i < length; i++)
{
long itemIDB = userPreferences.getItemID(i);
float bValue = userPreferences.getValue(i);
if (itemIDA < itemIDB)
{
RunningAverage average = aMap.get(itemIDB);
if (average == null)
{
average = buildRunningAverage();
aMap.put(itemIDB, average);
}
average.addDatum(bValue - prefValue);
}
else
{
FastByIDMap <RunningAverage> bMap = averageDiffs.get(itemIDB);
if (bMap == null)
{
bMap = new FastByIDMap <RunningAverage>();
averageDiffs.put(itemIDB, bMap);
}
RunningAverage average = bMap.get(itemIDA);
if (average == null)
{
average = buildRunningAverage();
bMap.put(itemIDA, average);
}
average.addDatum(prefValue - bValue);
}
}
}
finally
{
buildAverageDiffsLock.ExitWriteLock();
}
}
public override int getNumUsersWithPreferenceFor(long itemID1, long itemID2)
{
PreferenceArray array = this.preferenceForItems.get(itemID1);
if (array == null)
{
return(0);
}
PreferenceArray array2 = this.preferenceForItems.get(itemID2);
if (array2 == null)
{
return(0);
}
int num = array.length();
int num2 = array2.length();
int num3 = 0;
int i = 0;
int num5 = 0;
long num6 = array.getUserID(0);
long num7 = array2.getUserID(0);
while (true)
{
if (num6 < num7)
{
if (++i == num)
{
return(num3);
}
num6 = array.getUserID(i);
}
else if (num6 > num7)
{
if (++num5 == num2)
{
return(num3);
}
num7 = array2.getUserID(num5);
}
else
{
num3++;
if ((++i == num) || (++num5 == num2))
{
return(num3);
}
num6 = array.getUserID(i);
num7 = array2.getUserID(num5);
}
}
}
private static float?getPreferenceForItem(PreferenceArray preferencesFromUser, long itemID)
{
int num = preferencesFromUser.length();
for (int i = 0; i < num; i++)
{
if (preferencesFromUser.getItemID(i) == itemID)
{
return(new float?(preferencesFromUser.getValue(i)));
}
}
return(null);
}
public override PreferenceArray getPreferencesForItem(long itemID)
{
int num;
if (this.tempPrefs.Count == 0)
{
return(base.getDelegate().getPreferencesForItem(itemID));
}
PreferenceArray array = null;
try
{
array = base.getDelegate().getPreferencesForItem(itemID);
}
catch (NoSuchItemException)
{
}
List <Preference> list = new List <Preference>();
foreach (KeyValuePair <long, PreferenceArray> pair in this.tempPrefs)
{
PreferenceArray array2 = pair.Value;
num = 0;
while (num < array2.length())
{
if (array2.getItemID(num) == itemID)
{
list.Add(array2.get(num));
}
num++;
}
}
int num2 = (array == null) ? 0 : array.length();
int count = list.Count;
int num4 = 0;
PreferenceArray array3 = new GenericItemPreferenceArray(num2 + count);
for (num = 0; num < num2; num++)
{
array3.set(num4++, array.get(num));
}
foreach (Preference preference in list)
{
array3.set(num4++, preference);
}
if (array3.length() == 0)
{
throw new NoSuchItemException(itemID);
}
return(array3);
}
public override float?getPreferenceValue(long userID, long itemID)
{
PreferenceArray array = this.getPreferencesFromUser(userID);
int num = array.length();
for (int i = 0; i < num; i++)
{
if (array.getItemID(i) == itemID)
{
return(new float?(array.getValue(i)));
}
}
return(null);
}
public FastIDSet getRelevantItemsIDs(long userID, int at, double relevanceThreshold, DataModel dataModel)
{
PreferenceArray array = dataModel.getPreferencesFromUser(userID);
FastIDSet set = new FastIDSet(at);
array.sortByValueReversed();
for (int i = 0; (i < array.length()) && (set.size() < at); i++)
{
if (array.getValue(i) >= relevanceThreshold)
{
set.add(array.getItemID(i));
}
}
return(set);
}
private static long setBits(FastIDSet modelSet, PreferenceArray prefs, int max)
{
long num = -1L;
for (int i = 0; (i < prefs.length()) && (i < max); i++)
{
long key = prefs.getItemID(i);
modelSet.add(key);
if (key > num)
{
num = key;
}
}
return(num);
}
public override float?getPreferenceValue(long userID, long itemID)
{
if (this.isAnonymousUser(userID))
{
PreferenceArray array = this.tempPrefs[userID];
for (int i = 0; i < array.length(); i++)
{
if (array.getItemID(i) == itemID)
{
return(new float?(array.getValue(i)));
}
}
return(null);
}
return(base.getDelegate().getPreferenceValue(userID, itemID));
}
protected override FastIDSet doGetCandidateItems(long[] preferredItemIDs, DataModel dataModel)
{
FastIDSet set = new FastIDSet();
foreach (long num in preferredItemIDs)
{
PreferenceArray array = dataModel.getPreferencesForItem(num);
int num2 = array.length();
for (int i = 0; i < num2; i++)
{
set.addAll(dataModel.getItemIDsFromUser(array.getUserID(i)));
}
}
set.removeAll(preferredItemIDs);
return(set);
}
public List <RecommendedItem> recommendedBecause(long userID, long itemID, int howMany)
{
DataModel model = this.getDataModel();
TopItems.Estimator <long> estimator = new RecommendedBecauseEstimator(this, userID, itemID);
PreferenceArray array = model.getPreferencesFromUser(userID);
int size = array.length();
FastIDSet set = new FastIDSet(size);
for (int i = 0; i < size; i++)
{
set.add(array.getItemID(i));
}
set.remove(itemID);
return(TopItems.getTopItems(howMany, set.GetEnumerator(), null, estimator));
}
public float get(long key)
{
PreferenceArray array = this.inf.dataModel.getPreferencesFromUser(key);
int num = array.length();
if (num == 0)
{
return(AveragingPreferenceInferrer.ZERO);
}
RunningAverage average = new FullRunningAverage();
for (int i = 0; i < num; i++)
{
average.addDatum((double)array.getValue(i));
}
return((float)average.getAverage());
}
public static FastByIDMap <FastIDSet> toDataMap(FastByIDMap <PreferenceArray> data)
{
FastByIDMap <FastIDSet> map = new FastByIDMap <FastIDSet>(data.size());
foreach (KeyValuePair <long, PreferenceArray> pair in data.entrySet())
{
PreferenceArray array = pair.Value;
int size = array.length();
FastIDSet set = new FastIDSet(size);
for (int i = 0; i < size; i++)
{
set.add(array.getItemID(i));
}
map.put(pair.Key, set);
}
return(map);
}
public override List <RecommendedItem> recommend(long userID, int howMany, IDRescorer rescorer)
{
log.debug("Recommending items for user ID '{}'", new object[] { userID });
PreferenceArray preferencesFromUser = this.getDataModel().getPreferencesFromUser(userID);
if (preferencesFromUser.length() == 0)
{
return(new List <RecommendedItem>());
}
FastIDSet set = this.getAllOtherItems(userID, preferencesFromUser);
TopItems.Estimator <long> estimator = new Estimator(this, userID, preferencesFromUser);
List <RecommendedItem> list = TopItems.getTopItems(howMany, set.GetEnumerator(), rescorer, estimator);
log.debug("Recommendations are: {}", new object[] { list });
return(list);
}
private static long[] getCommonItems(FastIDSet commonSet, PreferenceArray prefs1, int max)
{
long[] numArray = new long[max];
int num = 0;
for (int i = 0; i < prefs1.length(); i++)
{
long key = prefs1.getItemID(i);
if (commonSet.contains(key))
{
numArray[num++] = key;
}
if (num == max)
{
return(numArray);
}
}
return(numArray);
}
private long processOneUser(long averageCount, long userID)
{
log.debug("Processing prefs for user {}", userID);
// Save off prefs for the life of this loop iteration
PreferenceArray userPreferences = dataModel.getPreferencesFromUser(userID);
int length = userPreferences.length();
for (int i = 0; i < length - 1; i++)
{
float prefAValue = userPreferences.getValue(i);
long itemIDA = userPreferences.getItemID(i);
FastByIDMap <RunningAverage> aMap = averageDiffs.get(itemIDA);
if (aMap == null)
{
aMap = new FastByIDMap <RunningAverage>();
averageDiffs.put(itemIDA, aMap);
}
for (int j = i + 1; j < length; j++)
{
// This is a performance-critical block
long itemIDB = userPreferences.getItemID(j);
RunningAverage average = aMap.get(itemIDB);
if (average == null && averageCount < maxEntries)
{
average = buildRunningAverage();
aMap.put(itemIDB, average);
averageCount++;
}
if (average != null)
{
average.addDatum(userPreferences.getValue(j) - prefAValue);
}
}
RunningAverage itemAverage = averageItemPref.get(itemIDA);
if (itemAverage == null)
{
itemAverage = buildRunningAverage();
averageItemPref.put(itemIDA, itemAverage);
}
itemAverage.addDatum(prefAValue);
}
return(averageCount);
}
private void buildAverageDiffs()
{
lock (this)
{
DataModel model = this.getDataModel();
IEnumerator <long> enumerator = model.getUserIDs();
while (enumerator.MoveNext())
{
long current = enumerator.Current;
PreferenceArray array = model.getPreferencesFromUser(current);
int num2 = array.length();
for (int i = 0; i < num2; i++)
{
long itemID = array.getItemID(i);
float num5 = array.getValue(i);
addDatumAndCreateIfNeeded(itemID, num5, this.itemAverages);
addDatumAndCreateIfNeeded(current, num5, this.userAverages);
this.overallAveragePrefValue.addDatum((double)num5);
}
}
}
}
protected override FastIDSet doGetCandidateItems(long[] preferredItemIDs, DataModel dataModel)
{
IEnumerator <long> enumerator = ((IEnumerable <long>)preferredItemIDs).GetEnumerator();
if (preferredItemIDs.Length > this.maxItems)
{
double samplingRate = ((double)this.maxItems) / ((double)preferredItemIDs.Length);
log.info("preferredItemIDs.Length {0}, samplingRate {1}", new object[] { preferredItemIDs.Length, samplingRate });
enumerator = new SamplingLongPrimitiveIterator(enumerator, samplingRate);
}
FastIDSet possibleItemIDs = new FastIDSet();
while (enumerator.MoveNext())
{
long current = enumerator.Current;
PreferenceArray array = dataModel.getPreferencesForItem(current);
int num3 = array.length();
if (num3 > this.maxUsersPerItem)
{
FixedSizeSamplingIterator <Preference> iterator = new FixedSizeSamplingIterator <Preference>(this.maxUsersPerItem, array.GetEnumerator());
while (iterator.MoveNext())
{
this.addSomeOf(possibleItemIDs, dataModel.getItemIDsFromUser(iterator.Current.getUserID()));
}
}
else
{
for (int i = 0; i < num3; i++)
{
this.addSomeOf(possibleItemIDs, dataModel.getItemIDsFromUser(array.getUserID(i)));
}
}
}
possibleItemIDs.removeAll(preferredItemIDs);
return(possibleItemIDs);
}
private void splitOneUsersPrefs(double trainingPercentage, FastByIDMap <PreferenceArray> trainingPrefs, FastByIDMap <PreferenceArray> testPrefs, long userID, DataModel dataModel)
{
List <Preference> prefs = null;
List <Preference> list2 = null;
PreferenceArray array = dataModel.getPreferencesFromUser(userID);
int num = array.length();
for (int i = 0; i < num; i++)
{
Preference item = new GenericPreference(userID, array.getItemID(i), array.getValue(i));
if (this.random.nextDouble() < trainingPercentage)
{
if (prefs == null)
{
prefs = new List <Preference>(3);
}
prefs.Add(item);
}
else
{
if (list2 == null)
{
list2 = new List <Preference>(3);
}
list2.Add(item);
}
}
if (prefs != null)
{
trainingPrefs.put(userID, new GenericUserPreferenceArray(prefs));
if (list2 != null)
{
testPrefs.put(userID, new GenericUserPreferenceArray(list2));
}
}
}
private void buildAverageDiffs()
{
lock (this)
{
DataModel model = this.getDataModel();
IEnumerator <long> enumerator = model.getUserIDs();
while (enumerator.MoveNext())
{
PreferenceArray array = model.getPreferencesFromUser(enumerator.Current);
int num = array.length();
for (int i = 0; i < num; i++)
{
long key = array.getItemID(i);
RunningAverage average = this.itemAverages.get(key);
if (average == null)
{
average = new FullRunningAverage();
this.itemAverages.put(key, average);
}
average.addDatum((double)array.getValue(i));
}
}
}
}
