org.apache.mahout.math.map
Class AbstractDoubleObjectMap<T>

java.lang.Object
  org.apache.mahout.math.PersistentObject
      org.apache.mahout.math.set.AbstractSet
          org.apache.mahout.math.map.AbstractDoubleObjectMap<T>

All Implemented Interfaces:

Serializable, Cloneable

Direct Known Subclasses:

OpenDoubleObjectHashMap

public abstract class AbstractDoubleObjectMap<T>
extends AbstractSet

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.mahout.math.set.AbstractSet

defaultCapacity, defaultMaxLoadFactor, defaultMinLoadFactor, distinct, highWaterMark, lowWaterMark, maxLoadFactor, minLoadFactor

Constructor Summary

AbstractDoubleObjectMap()

Method Summary

boolean	containsKey(double key) Returns true if the receiver contains the specified key.
boolean	containsValue(T value) Returns true if the receiver contains the specified value.
AbstractDoubleObjectMap<T>	copy() Returns a deep copy of the receiver; uses clone() and casts the result.
boolean	equals(Object obj) Compares the specified object with this map for equality.
abstract boolean	forEachKey(DoubleProcedure procedure) Applies a procedure to each key of the receiver, if any.
boolean	forEachPair(DoubleObjectProcedure<T> procedure) Applies a procedure to each (key,value) pair of the receiver, if any.
abstract T	get(double key) Returns the value associated with the specified key.
DoubleArrayList	keys() Returns a list filled with all keys contained in the receiver.
void	keys(DoubleArrayList list) Fills all keys contained in the receiver into the specified list.
void	keysSortedByValue(DoubleArrayList keyList) Fills all keys sorted ascending by their associated value into the specified list.
void	pairsMatching(DoubleObjectProcedure<T> condition, DoubleArrayList keyList, List<T> valueList) Fills all pairs satisfying a given condition into the specified lists.
void	pairsSortedByKey(DoubleArrayList keyList, List<T> valueList) Fills all keys and values sorted ascending by key into the specified lists.
void	pairsSortedByValue(DoubleArrayList keyList, List<T> valueList) Fills all keys and values sorted ascending by value according to natural ordering into the specified lists.
abstract boolean	put(double key, T value) Associates the given key with the given value.
abstract boolean	removeKey(double key) Removes the given key with its associated element from the receiver, if present.
String	toString() Returns a string representation of the receiver, containing the String representation of each key-value pair, sorted ascending by key.
String	toStringByValue() Returns a string representation of the receiver, containing the String representation of each key-value pair, sorted ascending by value, according to natural ordering.
List<T>	values() Returns a list filled with all values contained in the receiver.
void	values(List<T> list) Fills all values contained in the receiver into the specified list.

Methods inherited from class org.apache.mahout.math.set.AbstractSet

chooseGrowCapacity, chooseHighWaterMark, chooseLowWaterMark, chooseMeanCapacity, chooseShrinkCapacity, clear, ensureCapacity, equalsMindTheNull, isEmpty, nextPrime, setUp, size, trimToSize

Methods inherited from class org.apache.mahout.math.PersistentObject

clone

Methods inherited from class java.lang.Object

finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

AbstractDoubleObjectMap

public AbstractDoubleObjectMap()

Method Detail

containsKey

public boolean containsKey(double key)

Returns true if the receiver contains the specified key.

Returns:

true if the receiver contains the specified key.

containsValue

public boolean containsValue(T value)

Returns true if the receiver contains the specified value. Tests for identity.

Returns:

true if the receiver contains the specified value.

copy

public AbstractDoubleObjectMap<T> copy()

Returns a deep copy of the receiver; uses clone() and casts the result.

Returns:

a deep copy of the receiver.

equals

public boolean equals(Object obj)

Compares the specified object with this map for equality. Returns true if the given object is also a map and the two maps represent the same mappings. More formally, two maps m1 and m2 represent the same mappings iff

 m1.forEachPair(
    new DoubleObjectProcedure() {
      public boolean apply(double key, Object value) {
        return m2.containsKey(key) && m2.get(key) == value;
      }
    }
  )
 &&
 m2.forEachPair(
    new DoubleObjectProcedure() {
      public boolean apply(double key, Object value) {
        return m1.containsKey(key) && m1.get(key) == value;
      }
    }
  );
 

This implementation first checks if the specified object is this map; if so it returns true. Then, it checks if the specified object is a map whose size is identical to the size of this set; if not, it it returns false. If so, it applies the iteration as described above.

Overrides:

equals in class Object

Parameters:

obj - object to be compared for equality with this map.

Returns:

true if the specified object is equal to this map.

forEachKey

public abstract boolean forEachKey(DoubleProcedure procedure)

Applies a procedure to each key of the receiver, if any. Note: Iterates over the keys in no particular order. Subclasses can define a particular order, for example, "sorted by key". All methods which can be expressed in terms of this method (most methods can) must guarantee to use the same order defined by this method, even if it is no particular order. This is necessary so that, for example, methods keys and values will yield association pairs, not two uncorrelated lists.

Parameters:

procedure - the procedure to be applied. Stops iteration if the procedure returns false, otherwise continues.

Returns:

false if the procedure stopped before all keys where iterated over, true otherwise.

forEachPair

public boolean forEachPair(DoubleObjectProcedure<T> procedure)

Applies a procedure to each (key,value) pair of the receiver, if any. Iteration order is guaranteed to be identical to the order used by method #forEachKey(${keyTypeCap}Procedure).

Parameters:

procedure - the procedure to be applied. Stops iteration if the procedure returns false, otherwise continues.

Returns:

false if the procedure stopped before all keys where iterated over, true otherwise.

get

public abstract T get(double key)

Returns the value associated with the specified key. It is often a good idea to first check with #containsKey(${keyType}) whether the given key has a value associated or not, i.e. whether there exists an association for the given key or not.

Parameters:

key - the key to be searched for.

Returns:

the value associated with the specified key; null if no such key is present.

keys

public DoubleArrayList keys()

Returns a list filled with all keys contained in the receiver. The returned list has a size that equals this.size(). Iteration order is guaranteed to be identical to the order used by method #forEachKey(${keyTypeCap}Procedure).

This method can be used to iterate over the keys of the receiver.

Returns:

the keys.

keys

public void keys(DoubleArrayList list)

Fills all keys contained in the receiver into the specified list. Fills the list, starting at index 0. After this call returns the specified list has a new size that equals this.size(). Iteration order is guaranteed to be identical to the order used by method #forEachKey(${keyTypeCap}Procedure).

This method can be used to iterate over the keys of the receiver.

Parameters:

list - the list to be filled, can have any size.

keysSortedByValue

public void keysSortedByValue(DoubleArrayList keyList)

Fills all keys sorted ascending by their associated value into the specified list. Fills into the list, starting at index 0. After this call returns the specified list has a new size that equals this.size(). Primary sort criterium is "value", secondary sort criterium is "key". This means that if any two values are equal, the smaller key comes first.

Example:
keys = (8,7,6), values = (1,2,2) --> keyList = (8,6,7)

Parameters:

keyList - the list to be filled, can have any size.

pairsMatching

public void pairsMatching(DoubleObjectProcedure<T> condition,
                          DoubleArrayList keyList,
                          List<T> valueList)

Fills all pairs satisfying a given condition into the specified lists. Fills into the lists, starting at index 0. After this call returns the specified lists both have a new size, the number of pairs satisfying the condition. Iteration order is guaranteed to be identical to the order used by method #forEachKey(${keyTypeCap}Procedure).

Example:

 DoubleObjectProcedure condition = new DoubleObjectProcedure() { // match even keys only
 public boolean apply(double key, Object value) { return key%2==0; }
 }
 keys = (8,7,6), values = (1,2,2) --> keyList = (6,8), valueList = (2,1)
 

Parameters:

condition - the condition to be matched. Takes the current key as first and the current value as second argument.

keyList - the list to be filled with keys, can have any size.

valueList - the list to be filled with values, can have any size.

pairsSortedByKey

public void pairsSortedByKey(DoubleArrayList keyList,
                             List<T> valueList)

Fills all keys and values sorted ascending by key into the specified lists. Fills into the lists, starting at index 0. After this call returns the specified lists both have a new size that equals this.size().

Example:
keys = (8,7,6), values = (1,2,2) --> keyList = (6,7,8), valueList = (2,2,1)

Parameters:

keyList - the list to be filled with keys, can have any size.

valueList - the list to be filled with values, can have any size.

pairsSortedByValue

public void pairsSortedByValue(DoubleArrayList keyList,
                               List<T> valueList)

Fills all keys and values sorted ascending by value according to natural ordering into the specified lists. Fills into the lists, starting at index 0. After this call returns the specified lists both have a new size that equals this.size(). Primary sort criterium is "value", secondary sort criterium is "key". This means that if any two values are equal, the smaller key comes first.

Example:
keys = (8,7,6), values = (1,2,2) --> keyList = (8,6,7), valueList = (1,2,2)

Parameters:

keyList - the list to be filled with keys, can have any size.

valueList - the list to be filled with values, can have any size.

put

public abstract boolean put(double key,
                            T value)

Associates the given key with the given value. Replaces any old (key,someOtherValue) association, if existing.

Parameters:

key - the key the value shall be associated with.

value - the value to be associated.

Returns:

true if the receiver did not already contain such a key; false if the receiver did already contain such a key - the new value has now replaced the formerly associated value.

removeKey

public abstract boolean removeKey(double key)

Removes the given key with its associated element from the receiver, if present.

Parameters:

key - the key to be removed from the receiver.

Returns:

true if the receiver contained the specified key, false otherwise.

toString

public String toString()

Returns a string representation of the receiver, containing the String representation of each key-value pair, sorted ascending by key.

Overrides:

toString in class Object

toStringByValue

public String toStringByValue()

Returns a string representation of the receiver, containing the String representation of each key-value pair, sorted ascending by value, according to natural ordering.

values

public List<T> values()

Returns a list filled with all values contained in the receiver. The returned list has a size that equals this.size(). Iteration order is guaranteed to be identical to the order used by method #forEachKey(${keyTypeCap}Procedure).

This method can be used to iterate over the values of the receiver.

Returns:

the values.

values

public void values(List<T> list)

Fills all values contained in the receiver into the specified list. Fills the list, starting at index 0. After this call returns the specified list has a new size that equals this.size(). Iteration order is guaranteed to be identical to the order used by method #forEachKey(${keyTypeCap}Procedure).

This method can be used to iterate over the values of the receiver.

Parameters:

list - the list to be filled, can have any size.