edu.umd.cloud9.io
Class VectorFloat<F extends WritableComparable>

java.lang.Object
  java.util.AbstractMap<K,V>
      java.util.HashMap<F,Float>
          edu.umd.cloud9.io.VectorFloat<F>

Type Parameters:

F - type of feature

All Implemented Interfaces:

Serializable, Cloneable, Map<F,Float>, Writable

public class VectorFloat<F extends WritableComparable>
extends HashMap<F,Float>
implements Writable

Writable representing a vector of float values. This generic class, based on the Java HashMap, supports the use of any class for the features (i.e., component of the vector), but all values are floats.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class java.util.AbstractMap

AbstractMap.SimpleEntry<K,V>, AbstractMap.SimpleImmutableEntry<K,V>

Constructor Summary

VectorFloat()
Creates a VectorFloat object.

Method Summary

float	dot(VectorFloat<F> v) Computes the dot product between this vector and another vector.
float	get(F f) Returns the value of a feature.
SortedSet<Map.Entry<F,Float>>	getSortedEntries() Returns feature-value entries sorted by descending value.
SortedSet<Map.Entry<F,Float>>	getSortedEntries(int n) Returns top n feature-value entries sorted by descending value.
float	length() Computes the length of this vector.
void	normalize() Normalizes this vector to a unit-length vector.
void	plus(VectorFloat<F> v) Adds another vector to this vector, based on feature-wise addition.
void	readFields(DataInput in) Deserializes the vector.
void	set(F f, float v) Sets the value of a feature.
void	write(DataOutput out) Serializes the vector.

Methods inherited from class java.util.HashMap

clear, clone, containsKey, containsValue, entrySet, get, isEmpty, keySet, put, putAll, remove, size, values

Methods inherited from class java.util.AbstractMap

equals, hashCode, toString

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map

equals, hashCode

Constructor Detail

VectorFloat

public VectorFloat()

Creates a VectorFloat object.

Method Detail

readFields

public void readFields(DataInput in)
                throws IOException

Deserializes the vector.

Specified by:

readFields in interface Writable

Parameters:

in - source for raw byte representation

Throws:

IOException

write

public void write(DataOutput out)
           throws IOException

Serializes the vector.

Specified by:

write in interface Writable

Parameters:

out - where to write the raw byte representation

Throws:

IOException

set

public void set(F f,
                float v)

Sets the value of a feature.

Parameters:

f - the feature

v - the value

get

public float get(F f)

Returns the value of a feature.

Parameters:

f - the feature

Returns:

the value of the feature

plus

public void plus(VectorFloat<F> v)

Adds another vector to this vector, based on feature-wise addition.

Parameters:

v - vector to add

dot

public float dot(VectorFloat<F> v)

Computes the dot product between this vector and another vector.

Parameters:

v - the other vector

length

public float length()

Computes the length of this vector.

Returns:

length of tis vector

normalize

public void normalize()

Normalizes this vector to a unit-length vector.

getSortedEntries

public SortedSet<Map.Entry<F,Float>> getSortedEntries()

Returns feature-value entries sorted by descending value. Ties broken by the natural sort order of the feature.

Returns:

feature-value entries sorted by descending value

getSortedEntries

public SortedSet<Map.Entry<F,Float>> getSortedEntries(int n)

Returns top n feature-value entries sorted by descending value. Ties broken by the natural sort order of the feature.

Parameters:

n - number of entries to return

Returns:

top n feature-value entries sorted by descending value