Package org.apache.commons.math.util

Class OpenIntToDoubleHashMap

java.lang.Object
org.apache.commons.math.util.OpenIntToDoubleHashMap
All Implemented Interfaces:
Serializable
public class OpenIntToDoubleHashMap extends Object implements Serializable
Open addressed map from int to double.

This class provides a dedicated map from integers to doubles with a much smaller memory overhead than standard java.util.Map.

This class is not synchronized. The specialized iterators returned by iterator() are fail-fast: they throw a ConcurrentModificationException when they detect the map has been modified during iteration.

Since:
2.0
See Also:

  • Constructor Details

    • OpenIntToDoubleHashMap

      public OpenIntToDoubleHashMap()
      Build an empty map with default size and using NaN for missing entries.

    • OpenIntToDoubleHashMap

      public OpenIntToDoubleHashMap(double missingEntries)
      Build an empty map with default size
      Parameters:
      missingEntries - value to return when a missing entry is fetched

    • OpenIntToDoubleHashMap

      public OpenIntToDoubleHashMap(int expectedSize)
      Build an empty map with specified size and using NaN for missing entries.
      Parameters:
      expectedSize - expected number of elements in the map

    • OpenIntToDoubleHashMap

      public OpenIntToDoubleHashMap(int expectedSize, double missingEntries)
      Build an empty map with specified size.
      Parameters:
      expectedSize - expected number of elements in the map
      missingEntries - value to return when a missing entry is fetched

    • OpenIntToDoubleHashMap

      public OpenIntToDoubleHashMap(OpenIntToDoubleHashMap source)
      Copy constructor.
      Parameters:
      source - map to copy

  • Method Details

    • get

      public double get(int key)
      Get the stored value associated with the given key
      Parameters:
      key - key associated with the data
      Returns:
      data associated with the key

    • containsKey

      public boolean containsKey(int key)
      Check if a value is associated with a key.
      Parameters:
      key - key to check
      Returns:
      true if a value is associated with key

    • iterator

      public OpenIntToDoubleHashMap.Iterator iterator()
      Get an iterator over map elements.

      The specialized iterators returned are fail-fast: they throw a ConcurrentModificationException when they detect the map has been modified during iteration.

      Returns:
      iterator over the map elements

    • size

      public int size()
      Get the number of elements stored in the map.
      Returns:
      number of elements stored in the map

    • remove

      public double remove(int key)
      Remove the value associated with a key.
      Parameters:
      key - key to which the value is associated
      Returns:
      removed value

    • put

      public double put(int key, double value)
      Put a value associated with a key in the map.
      Parameters:
      key - key to which value is associated
      value - value to put in the map
      Returns:
      previous value associated with the key