Package org.tribuo.impl

Class IndexedArrayExample<T extends Output<T>>

java.lang.Object
org.tribuo.Example<T>
org.tribuo.impl.ArrayExample<T>
org.tribuo.impl.IndexedArrayExample<T>
All Implemented Interfaces:
Serializable, Iterable<Feature>
public class IndexedArrayExample<T extends Output<T>> extends ArrayExample<T>
A version of ArrayExample which also has the id numbers.

Used in feature selection to provide log n lookups. May be used elsewhere in the future as a performance optimisation.

Note: output id caching is only valid with single dimensional Outputs like ClusterID, Event and Label. Other outputs may return -1 from getOutputID().

See Also:

  • Field Details

    • featureIDs

      protected int[] featureIDs
      Feature id numbers from the internal featureMap.

    • outputID

      protected final int outputID
      Output id from the internal output map. Note this only works for single dimensional outputs, in multi-dimensional cases it is likely to be -1.

  • Constructor Details

    • IndexedArrayExample

      public IndexedArrayExample(IndexedArrayExample<T> other)
      Copy constructor.
      Parameters:
      other - The example to copy.

    • IndexedArrayExample

      public IndexedArrayExample(Example<T> other, ImmutableFeatureMap featureMap, ImmutableOutputInfo<T> outputMap)
      This constructor removes unknown features.
      Parameters:
      other - The example to copy from.
      featureMap - The feature map.
      outputMap - The output info.

  • Method Details

    • equals

      public boolean equals(Object o)
      Overrides:
      equals in class ArrayExample<T extends Output<T>>

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class ArrayExample<T extends Output<T>>

    • growArray

      protected void growArray(int minCapacity)
      Description copied from class: ArrayExample
      Grows the backing arrays storing the names and values.
      Overrides:
      growArray in class ArrayExample<T extends Output<T>>
      Parameters:
      minCapacity - The new minimum capacity required.

    • add

      public void add(Feature feature)
      Description copied from class: Example
      Adds a feature. This maintains the sorted invariant and has a lg(example.size()) cost per insertion.
      Overrides:
      add in class ArrayExample<T extends Output<T>>
      Parameters:
      feature - The feature to add.

    • addAll

      public void addAll(Collection<? extends Feature> features)
      Description copied from class: Example
      Adds a collection of features. This maintains the sorted invariant but is more efficient than adding one at a time due to allocation.
      Overrides:
      addAll in class ArrayExample<T extends Output<T>>
      Parameters:
      features - The features to add.

    • sort

      protected void sort()
      Description copied from class: ArrayExample
      Sorts the feature list to maintain the lexicographic order invariant.
      Overrides:
      sort in class ArrayExample<T extends Output<T>>

    • reduceByName

      public void reduceByName(Merger merger)
      Description copied from class: Example
      Merges features with the same name using the supplied Merger.
      Overrides:
      reduceByName in class ArrayExample<T extends Output<T>>
      Parameters:
      merger - A function to merge two doubles.

    • removeFeatures

      public void removeFeatures(List<Feature> featureList)
      Description copied from class: Example
      Removes all features in this list from the Example.
      Overrides:
      removeFeatures in class ArrayExample<T extends Output<T>>
      Parameters:
      featureList - Features to remove from this Example.

    • contains

      public boolean contains(int i)
      Does this example contain a feature with id i.
      Parameters:
      i - The index to check.
      Returns:
      True if the example contains the id.

    • copy

      public IndexedArrayExample<T> copy()
      Description copied from class: Example
      Returns a deep copy of this Example.
      Overrides:
      copy in class ArrayExample<T extends Output<T>>
      Returns:
      A deep copy of this example.

    • densify

      public void densify(List<String> featureList)
      Description copied from class: Example
      Converts all implicit zeros into explicit zeros based on the supplied feature names.
      Overrides:
      densify in class ArrayExample<T extends Output<T>>
      Parameters:
      featureList - A *sorted* list of feature names.

    • getIdx

      public int getIdx(int i)
      Gets the feature at internal index i.
      Parameters:
      i - The internal index.
      Returns:
      The feature index.

    • getOutputID

      public int getOutputID()
      Gets the output id dimension number.
      Returns:
      The output id.

    • idIterator

      public Iterable<IndexedArrayExample.FeatureTuple> idIterator()
      Iterator over the feature ids and values.
      Returns:
      The feature ids and values.