Package org.tribuo.impl

Class ArrayExample<T extends Output<T>>

java.lang.Object
org.tribuo.Example<T>
org.tribuo.impl.ArrayExample<T>
All Implemented Interfaces:
Serializable, Iterable<Feature>
Direct Known Subclasses:
IndexedArrayExample
public class ArrayExample<T extends Output<T>> extends Example<T>
An Example backed by two arrays, one of String and one of double.
See Also:

  • Field Details

    • DEFAULT_SIZE

      public static final int DEFAULT_SIZE
      Default initial size of the backing arrays.
      See Also:

    • featureNames

      protected String[] featureNames
      Feature names array.

    • featureValues

      protected double[] featureValues
      Feature values array.

    • size

      protected int size
      Number of valid features in this example.

  • Constructor Details

    • ArrayExample

      public ArrayExample(T output, float weight, int initialSize)
      Constructs an example from an output and a weight, with an initial size for the feature arrays.
      Parameters:
      output - The output.
      weight - The weight.
      initialSize - The initial size of the feature arrays.

    • ArrayExample

      public ArrayExample(T output, float weight, Map<String,Object> metadata)
      Constructs an example from an output, a weight and the metadata.
      Parameters:
      output - The output.
      weight - The weight.
      metadata - The metadata.

    • ArrayExample

      public ArrayExample(T output, float weight)
      Constructs an example from an output and a weight.
      Parameters:
      output - The output.
      weight - The example weight.

    • ArrayExample

      public ArrayExample(T output, Map<String,Object> metadata)
      Constructs an example from an output and the metadata.
      Parameters:
      output - The output.
      metadata - The metadata.

    • ArrayExample

      public ArrayExample(T output)
      Constructs an example from an output.
      Parameters:
      output - The output.

    • ArrayExample

      public ArrayExample(T output, String[] names, double[] values)
      Constructs an example from an output, an array of names and an array of values. This is currently the most efficient constructor.
      Parameters:
      output - The output.
      names - The feature names.
      values - The feature values.

    • ArrayExample

      public ArrayExample(T output, List<? extends Feature> features)
      Constructs an example from an output and a list of features.
      Parameters:
      output - The output.
      features - The list of features.

    • ArrayExample

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

    • ArrayExample

      public ArrayExample(T output, Example<U> other, float weight)
      Clones an example's features, but uses the supplied output and weight.
      Type Parameters:
      U - The output type of the other example.
      Parameters:
      output - The output to use.
      other - The features to use.
      weight - The weight to use.

  • Method Details

    • add

      public void add(String name, double value)
      Adds a single feature.
      Parameters:
      name - The name of the feature.
      value - The value of the feature.

    • 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.
      Specified by:
      add in class Example<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.
      Specified by:
      addAll in class Example<T extends Output<T>>
      Parameters:
      features - The features to add.

    • growArray

      protected void growArray(int minCapacity)
      Grows the backing arrays storing the names and values.
      Parameters:
      minCapacity - The new minimum capacity required.

    • growArray

      protected void growArray()
      Grows the backing arrays by size+1.

    • newCapacity

      protected int newCapacity(int minCapacity)
      Returns a capacity at least as large as the given minimum capacity. Returns the current capacity increased by 50% if that suffices. Will not return a capacity greater than MAX_ARRAY_SIZE unless the given minimum capacity is greater than MAX_ARRAY_SIZE.
      Parameters:
      minCapacity - the desired minimum capacity
      Returns:
      The new capacity.
      Throws:
      OutOfMemoryError - if minCapacity is less than zero

    • sort

      protected void sort()
      Sorts the feature list to maintain the lexicographic order invariant.
      Specified by:
      sort in class Example<T extends Output<T>>

    • copyValues

      public double[] copyValues(int newSize)
      Returns a copy of the feature values array at the specific size.
      Parameters:
      newSize - The new size.
      Returns:
      A copy of the feature values.

    • size

      public int size()
      Description copied from class: Example
      Return how many features are in this example.
      Specified by:
      size in class Example<T extends Output<T>>
      Returns:
      The number of features.

    • removeFeatures

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

    • reduceByName

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

    • validateExample

      public boolean validateExample()
      Description copied from class: Example
      Checks the example to see if all the feature names are unique, the feature values are not NaN, and there is at least one feature.
      Specified by:
      validateExample in class Example<T extends Output<T>>
      Returns:
      true if the example is valid.

    • copy

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

    • lookup

      public Feature lookup(String i)
      Description copied from class: Example
      Returns the Feature in this Example which has the supplied name, if it's present.
      Overrides:
      lookup in class Example<T extends Output<T>>
      Parameters:
      i - The feature name to lookup.
      Returns:
      The feature object.

    • set

      public void set(Feature feature)
      Description copied from class: Example
      Overwrites the feature with the matching name.

      Throws IllegalArgumentException if there isn't a feature with that name in this example.

      Specified by:
      set in class Example<T extends Output<T>>
      Parameters:
      feature - The new feature value.

    • transform

      public void transform(TransformerMap transformerMap)
      Description copied from class: Example
      Transforms this example by applying the transformations from the supplied TransformerMap.

      Can be overridden for performance reasons.

      Overrides:
      transform in class Example<T extends Output<T>>
      Parameters:
      transformerMap - The transformations to apply.

    • isDense

      public boolean isDense(FeatureMap fMap)
      Description copied from class: Example
      Is this example dense wrt the supplied feature map.

      An example is "dense" if it contains all the features in the map, and only those features.

      Specified by:
      isDense in class Example<T extends Output<T>>
      Parameters:
      fMap - The feature map to check against.
      Returns:
      True if this example contains only the features in the map, and all the features in the map.

    • 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.
      Specified by:
      densify in class Example<T extends Output<T>>
      Parameters:
      featureList - A *sorted* list of feature names.

    • iterator

      public Iterator<Feature> iterator()

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • equals

      public boolean equals(Object o)
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • canonicalize

      public void canonicalize(FeatureMap featureMap)
      Description copied from class: Example
      Reassigns feature name Strings in the Example to point to those in the FeatureMap. This significantly reduces memory allocation. It is called when an Example is added to a MutableDataset, and should not be called outside of that context as it may interact unexpectedly with HashedFeatureMap.
      Specified by:
      canonicalize in class Example<T extends Output<T>>
      Parameters:
      featureMap - The feature map containing canonical feature names.