org.apache.mahout.math
Class DelegatingVector

java.lang.Object
  extended by org.apache.mahout.math.DelegatingVector
All Implemented Interfaces:
Cloneable, Vector
Direct Known Subclasses:
MatrixSlice, WeightedVector

public class DelegatingVector
extends Object
implements Vector

A delegating vector provides an easy way to decorate vectors with weights or id's and such while keeping all of the Vector functionality. This vector implements LengthCachingVector because almost all delegates cache the length and the cost of false positives is very low.


Nested Class Summary
 
Nested classes/interfaces inherited from interface org.apache.mahout.math.Vector
Vector.Element
 
Field Summary
protected  Vector delegate
           
 
Constructor Summary
protected DelegatingVector()
           
  DelegatingVector(Vector v)
           
 
Method Summary
 double aggregate(DoubleDoubleFunction aggregator, DoubleFunction map)
          Examples speak louder than words: aggregate(plus, pow(2)) is another way to say getLengthSquared(), aggregate(max, abs) is norm(Double.POSITIVE_INFINITY).
 double aggregate(Vector other, DoubleDoubleFunction aggregator, DoubleDoubleFunction combiner)
          Generalized inner product - take two vectors, iterate over them both, using the combiner to combine together (and possibly map in some way) each pair of values, which are then aggregated with the previous accumulated value in the combiner.
 Iterable<Vector.Element> all()
           
 String asFormatString()
           
 Vector assign(double value)
          Assign the value to all elements of the receiver
 Vector assign(double[] values)
          Assign the values to the receiver
 Vector assign(DoubleDoubleFunction f, double y)
          Apply the function to each element of the receiver, using the y value as the second argument of the DoubleDoubleFunction
 Vector assign(DoubleFunction function)
          Apply the function to each element of the receiver
 Vector assign(Vector other)
          Assign the other vector values to the receiver
 Vector assign(Vector other, DoubleDoubleFunction function)
          Apply the function to each element of the receiver and the corresponding element of the other argument
 Vector clone()
          Return a copy of the recipient
 Matrix cross(Vector other)
          Return the cross product of the receiver and the other vector
 Vector divide(double x)
          Return a new vector containing the values of the recipient divided by the argument
 double dot(Vector x)
          Return the dot product of the recipient and the argument
 boolean equals(Object o)
           
 double get(int index)
          Return the value at the given index
 double getDistanceSquared(Vector v)
          Get the square of the distance between this vector and the other vector.
 Vector.Element getElement(int index)
          Return an object of Vector.Element representing an element of this Vector.
 double getIteratorAdvanceCost()
          Gets an estimate of the cost (in number of operations) it takes to advance an iterator through the nonzero elements of this vector.
 double getLengthSquared()
          Return the sum of squares of all elements in the vector.
 double getLookupCost()
          Gets an estimate of the cost (in number of operations) it takes to lookup a random element in this vector.
 int getNumNondefaultElements()
          Return the number of values in the recipient which are not the default value.
 int getNumNonZeroElements()
          Return the number of non zero elements in the vector.
 double getQuick(int index)
          Return the value at the given index, without checking bounds
 Vector getVector()
           
 int hashCode()
           
 void incrementQuick(int index, double increment)
          Increment the value at the given index by the given value.
 void invalidateCachedLength()
          Invalidates the length cache.
 boolean isAddConstantTime()
          Return true iff adding a new (nonzero) element takes constant time for this vector.
 boolean isDense()
           
 boolean isSequentialAccess()
           
 Vector like()
          Return an empty vector of the same underlying class as the receiver
 Vector logNormalize()
          Return a new vector containing the log(1 + entry)/ L_2 norm values of the recipient
 Vector logNormalize(double power)
          Return a new Vector with a normalized value calculated as log_power(1 + entry)/ L_power norm.
 double maxValue()
           
 int maxValueIndex()
           
 void mergeUpdates(OrderedIntDoubleMapping updates)
          Merge a set of (index, value) pairs into the vector.
 Vector minus(Vector that)
          Return a new vector containing the element by element difference of the recipient and the argument
 double minValue()
           
 int minValueIndex()
           
 Iterable<Vector.Element> nonZeroes()
           
 double norm(double power)
          Return the k-norm of the vector.
 Vector normalize()
          Return a new vector containing the normalized (L_2 norm) values of the recipient
 Vector normalize(double power)
          Return a new Vector containing the normalized (L_power norm) values of the recipient.
 Vector plus(double x)
          Return a new vector containing the sum of each value of the recipient and the argument
 Vector plus(Vector x)
          Return a new vector containing the element by element sum of the recipient and the argument
 void set(int index, double value)
          Set the value at the given index
 void setQuick(int index, double value)
          Set the value at the given index, without checking bounds
 int size()
          Return the cardinality of the recipient (the maximum number of values)
 Vector times(double x)
          Return a new vector containing the product of each value of the recipient and the argument
 Vector times(Vector x)
          Return a new vector containing the element-wise product of the recipient and the argument
 String toString()
           
 Vector viewPart(int offset, int length)
          Return a new vector containing the subset of the recipient
 double zSum()
          Return the sum of all the elements of the receiver
 
Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait
 

Field Detail

delegate

protected Vector delegate
Constructor Detail

DelegatingVector

public DelegatingVector(Vector v)

DelegatingVector

protected DelegatingVector()
Method Detail

getVector

public Vector getVector()

aggregate

public double aggregate(DoubleDoubleFunction aggregator,
                        DoubleFunction map)
Description copied from interface: Vector
Examples speak louder than words: aggregate(plus, pow(2)) is another way to say getLengthSquared(), aggregate(max, abs) is norm(Double.POSITIVE_INFINITY). To sum all of the positive values, aggregate(plus, max(0)).

Specified by:
aggregate in interface Vector
Parameters:
aggregator - used to combine the current value of the aggregation with the result of map.apply(nextValue)
map - a function to apply to each element of the vector in turn before passing to the aggregator
Returns:
the final aggregation

aggregate

public double aggregate(Vector other,
                        DoubleDoubleFunction aggregator,
                        DoubleDoubleFunction combiner)
Description copied from interface: Vector

Generalized inner product - take two vectors, iterate over them both, using the combiner to combine together (and possibly map in some way) each pair of values, which are then aggregated with the previous accumulated value in the combiner.

Example: dot(other) could be expressed as aggregate(other, Plus, Times), and kernelized inner products (which are symmetric on the indices) work similarly.

Specified by:
aggregate in interface Vector
Parameters:
other - a vector to aggregate in combination with
aggregator - function we're aggregating with; fa
combiner - function we're combining with; fc
Returns:
the final aggregation; if r0 = fc(this[0], other[0]), ri = fa(r_{i-1}, fc(this[i], other[i])) for all i > 0

viewPart

public Vector viewPart(int offset,
                       int length)
Description copied from interface: Vector
Return a new vector containing the subset of the recipient

Specified by:
viewPart in interface Vector
Parameters:
offset - an int offset into the receiver
length - the cardinality of the desired result
Returns:
a new Vector

clone

public Vector clone()
Description copied from interface: Vector
Return a copy of the recipient

Specified by:
clone in interface Vector
Overrides:
clone in class Object
Returns:
a new Vector

all

public Iterable<Vector.Element> all()
Specified by:
all in interface Vector

nonZeroes

public Iterable<Vector.Element> nonZeroes()
Specified by:
nonZeroes in interface Vector

divide

public Vector divide(double x)
Description copied from interface: Vector
Return a new vector containing the values of the recipient divided by the argument

Specified by:
divide in interface Vector
Parameters:
x - a double value
Returns:
a new Vector

dot

public double dot(Vector x)
Description copied from interface: Vector
Return the dot product of the recipient and the argument

Specified by:
dot in interface Vector
Parameters:
x - a Vector
Returns:
a new Vector

get

public double get(int index)
Description copied from interface: Vector
Return the value at the given index

Specified by:
get in interface Vector
Parameters:
index - an int index
Returns:
the double at the index

getElement

public Vector.Element getElement(int index)
Description copied from interface: Vector
Return an object of Vector.Element representing an element of this Vector. Useful when designing new iterator types.

Specified by:
getElement in interface Vector
Parameters:
index - Index of the Vector.Element required
Returns:
The Vector.Element Object

mergeUpdates

public void mergeUpdates(OrderedIntDoubleMapping updates)
Merge a set of (index, value) pairs into the vector.

Specified by:
mergeUpdates in interface Vector
Parameters:
updates - an ordered mapping of indices to values to be merged in.

minus

public Vector minus(Vector that)
Description copied from interface: Vector
Return a new vector containing the element by element difference of the recipient and the argument

Specified by:
minus in interface Vector
Parameters:
that - a Vector
Returns:
a new Vector

normalize

public Vector normalize()
Description copied from interface: Vector
Return a new vector containing the normalized (L_2 norm) values of the recipient

Specified by:
normalize in interface Vector
Returns:
a new Vector

normalize

public Vector normalize(double power)
Description copied from interface: Vector
Return a new Vector containing the normalized (L_power norm) values of the recipient.

See http://en.wikipedia.org/wiki/Lp_space

Technically, when 0 < power < 1, we don't have a norm, just a metric, but we'll overload this here.

Also supports power == 0 (number of non-zero elements) and power = Double.POSITIVE_INFINITY (max element). Again, see the Wikipedia page for more info

Specified by:
normalize in interface Vector
Parameters:
power - The power to use. Must be >= 0. May also be Double.POSITIVE_INFINITY. See the Wikipedia link for more on this.
Returns:
a new Vector x such that norm(x, power) == 1

logNormalize

public Vector logNormalize()
Description copied from interface: Vector
Return a new vector containing the log(1 + entry)/ L_2 norm values of the recipient

Specified by:
logNormalize in interface Vector
Returns:
a new Vector

logNormalize

public Vector logNormalize(double power)
Description copied from interface: Vector
Return a new Vector with a normalized value calculated as log_power(1 + entry)/ L_power norm.

Specified by:
logNormalize in interface Vector
Parameters:
power - The power to use. Must be > 1. Cannot be Double.POSITIVE_INFINITY.
Returns:
a new Vector

norm

public double norm(double power)
Description copied from interface: Vector
Return the k-norm of the vector.

See http://en.wikipedia.org/wiki/Lp_space

Technically, when 0 > power < 1, we don't have a norm, just a metric, but we'll overload this here. Also supports power == 0 (number of non-zero elements) and power = Double.POSITIVE_INFINITY (max element). Again, see the Wikipedia page for more info.

Specified by:
norm in interface Vector
Parameters:
power - The power to use.
See Also:
Vector.normalize(double)

getLengthSquared

public double getLengthSquared()
Description copied from interface: Vector
Return the sum of squares of all elements in the vector. Square root of this value is the length of the vector.

Specified by:
getLengthSquared in interface Vector
Returns:
The sum of the squares of all elements in the vector.

invalidateCachedLength

public void invalidateCachedLength()
Invalidates the length cache. This should be called by all mutators of the vector.


getDistanceSquared

public double getDistanceSquared(Vector v)
Description copied from interface: Vector
Get the square of the distance between this vector and the other vector.

Specified by:
getDistanceSquared in interface Vector

getLookupCost

public double getLookupCost()
Description copied from interface: Vector
Gets an estimate of the cost (in number of operations) it takes to lookup a random element in this vector.

Specified by:
getLookupCost in interface Vector

getIteratorAdvanceCost

public double getIteratorAdvanceCost()
Description copied from interface: Vector
Gets an estimate of the cost (in number of operations) it takes to advance an iterator through the nonzero elements of this vector.

Specified by:
getIteratorAdvanceCost in interface Vector

isAddConstantTime

public boolean isAddConstantTime()
Description copied from interface: Vector
Return true iff adding a new (nonzero) element takes constant time for this vector.

Specified by:
isAddConstantTime in interface Vector

maxValue

public double maxValue()
Specified by:
maxValue in interface Vector
Returns:
The maximum value in the Vector

maxValueIndex

public int maxValueIndex()
Specified by:
maxValueIndex in interface Vector
Returns:
The index of the maximum value

minValue

public double minValue()
Specified by:
minValue in interface Vector
Returns:
The minimum value in the Vector

minValueIndex

public int minValueIndex()
Specified by:
minValueIndex in interface Vector
Returns:
The index of the minimum value

plus

public Vector plus(double x)
Description copied from interface: Vector
Return a new vector containing the sum of each value of the recipient and the argument

Specified by:
plus in interface Vector
Parameters:
x - a double
Returns:
a new Vector

plus

public Vector plus(Vector x)
Description copied from interface: Vector
Return a new vector containing the element by element sum of the recipient and the argument

Specified by:
plus in interface Vector
Parameters:
x - a Vector
Returns:
a new Vector

set

public void set(int index,
                double value)
Description copied from interface: Vector
Set the value at the given index

Specified by:
set in interface Vector
Parameters:
index - an int index into the receiver
value - a double value to set

times

public Vector times(double x)
Description copied from interface: Vector
Return a new vector containing the product of each value of the recipient and the argument

Specified by:
times in interface Vector
Parameters:
x - a double argument
Returns:
a new Vector

times

public Vector times(Vector x)
Description copied from interface: Vector
Return a new vector containing the element-wise product of the recipient and the argument

Specified by:
times in interface Vector
Parameters:
x - a Vector argument
Returns:
a new Vector

zSum

public double zSum()
Description copied from interface: Vector
Return the sum of all the elements of the receiver

Specified by:
zSum in interface Vector
Returns:
a double

assign

public Vector assign(double value)
Description copied from interface: Vector
Assign the value to all elements of the receiver

Specified by:
assign in interface Vector
Parameters:
value - a double value
Returns:
the modified receiver

assign

public Vector assign(double[] values)
Description copied from interface: Vector
Assign the values to the receiver

Specified by:
assign in interface Vector
Parameters:
values - a double[] of values
Returns:
the modified receiver

assign

public Vector assign(Vector other)
Description copied from interface: Vector
Assign the other vector values to the receiver

Specified by:
assign in interface Vector
Parameters:
other - a Vector
Returns:
the modified receiver

assign

public Vector assign(DoubleDoubleFunction f,
                     double y)
Description copied from interface: Vector
Apply the function to each element of the receiver, using the y value as the second argument of the DoubleDoubleFunction

Specified by:
assign in interface Vector
Parameters:
f - a DoubleDoubleFunction to be applied
y - a double value to be argument to the function
Returns:
the modified receiver

assign

public Vector assign(DoubleFunction function)
Description copied from interface: Vector
Apply the function to each element of the receiver

Specified by:
assign in interface Vector
Parameters:
function - a DoubleFunction to apply
Returns:
the modified receiver

assign

public Vector assign(Vector other,
                     DoubleDoubleFunction function)
Description copied from interface: Vector
Apply the function to each element of the receiver and the corresponding element of the other argument

Specified by:
assign in interface Vector
Parameters:
other - a Vector containing the second arguments to the function
function - a DoubleDoubleFunction to apply
Returns:
the modified receiver

cross

public Matrix cross(Vector other)
Description copied from interface: Vector
Return the cross product of the receiver and the other vector

Specified by:
cross in interface Vector
Parameters:
other - another Vector
Returns:
a Matrix

size

public int size()
Description copied from interface: Vector
Return the cardinality of the recipient (the maximum number of values)

Specified by:
size in interface Vector
Returns:
an int

asFormatString

public String asFormatString()
Specified by:
asFormatString in interface Vector
Returns:
a formatted String suitable for output

hashCode

public int hashCode()
Overrides:
hashCode in class Object

equals

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

toString

public String toString()
Overrides:
toString in class Object

isDense

public boolean isDense()
Specified by:
isDense in interface Vector
Returns:
true iff this implementation should be considered dense -- that it explicitly represents every value

isSequentialAccess

public boolean isSequentialAccess()
Specified by:
isSequentialAccess in interface Vector
Returns:
true iff this implementation should be considered to be iterable in index order in an efficient way. In particular this implies that Vector.all() and Vector.nonZeroes() ()} return elements in ascending order by index.

getQuick

public double getQuick(int index)
Description copied from interface: Vector
Return the value at the given index, without checking bounds

Specified by:
getQuick in interface Vector
Parameters:
index - an int index
Returns:
the double at the index

like

public Vector like()
Description copied from interface: Vector
Return an empty vector of the same underlying class as the receiver

Specified by:
like in interface Vector
Returns:
a Vector

setQuick

public void setQuick(int index,
                     double value)
Description copied from interface: Vector
Set the value at the given index, without checking bounds

Specified by:
setQuick in interface Vector
Parameters:
index - an int index into the receiver
value - a double value to set

incrementQuick

public void incrementQuick(int index,
                           double increment)
Description copied from interface: Vector
Increment the value at the given index by the given value.

Specified by:
incrementQuick in interface Vector
Parameters:
index - an int index into the receiver
increment - sets the value at the given index to value + increment;

getNumNondefaultElements

public int getNumNondefaultElements()
Description copied from interface: Vector
Return the number of values in the recipient which are not the default value. For instance, for a sparse vector, this would be the number of non-zero values.

Specified by:
getNumNondefaultElements in interface Vector
Returns:
an int

getNumNonZeroElements

public int getNumNonZeroElements()
Description copied from interface: Vector
Return the number of non zero elements in the vector.

Specified by:
getNumNonZeroElements in interface Vector
Returns:
an int


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