org.apache.mahout.cf.taste.impl.model
Class AbstractDataModel
java.lang.Object
org.apache.mahout.cf.taste.impl.model.AbstractDataModel
- All Implemented Interfaces:
- Serializable, Refreshable, DataModel
- Direct Known Subclasses:
- FileDataModel, GenericBooleanPrefDataModel, GenericDataModel
public abstract class AbstractDataModel
- extends Object
- implements DataModel
Contains some features common to all implementations.
- See Also:
- Serialized Form
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Methods inherited from interface org.apache.mahout.cf.taste.model.DataModel |
getItemIDs, getItemIDsFromUser, getNumItems, getNumUsers, getNumUsersWithPreferenceFor, getNumUsersWithPreferenceFor, getPreferencesForItem, getPreferencesFromUser, getPreferenceTime, getPreferenceValue, getUserIDs, hasPreferenceValues, removePreference, setPreference |
AbstractDataModel
protected AbstractDataModel()
getMaxPreference
public float getMaxPreference()
- Specified by:
getMaxPreference
in interface DataModel
- Returns:
- the maximum preference value that is possible in the current problem domain being evaluated. For
example, if the domain is movie ratings on a scale of 1 to 5, this should be 5. While a
Recommender
may estimate a preference value above 5.0, it
isn't "fair" to consider that the system is actually suggesting an impossible rating of, say, 5.4 stars.
In practice the application would cap this estimate to 5.0. Since evaluators evaluate
the difference between estimated and actual value, this at least prevents this effect from unfairly
penalizing a Recommender
setMaxPreference
protected void setMaxPreference(float maxPreference)
getMinPreference
public float getMinPreference()
- Specified by:
getMinPreference
in interface DataModel
- See Also:
DataModel.getMaxPreference()
setMinPreference
protected void setMinPreference(float minPreference)
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