org.apache.mahout.math
Class NamedVector

java.lang.Object
  extended by org.apache.mahout.math.NamedVector
All Implemented Interfaces:
java.lang.Cloneable, java.lang.Iterable<Vector.Element>, Vector

public class NamedVector
extends java.lang.Object
implements Vector


Nested Class Summary
 
Nested classes/interfaces inherited from interface org.apache.mahout.math.Vector
Vector.Element
 
Constructor Summary
NamedVector()
           
NamedVector(NamedVector other)
           
NamedVector(Vector delegate, java.lang.String name)
           
 
Method Summary
 void addTo(Vector v)
          Add the elements to the other vector and results are stored in that vector.
 double aggregate(BinaryFunction aggregator, UnaryFunction 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, BinaryFunction aggregator, BinaryFunction 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.
 java.lang.String asFormatString()
           
 Vector assign(BinaryFunction f, double y)
          Apply the function to each element of the receiver, using the y value as the second argument of the BinaryFunction
 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(UnaryFunction 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, BinaryFunction function)
          Apply the function to each element of the receiver and the corresponding element of the other argument
 NamedVector 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(java.lang.Object other)
          To not break transitivity with other Vectors, this does not compare name.
 double get(int index)
          Return the value at the given index
 Vector getDelegate()
           
 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 getLengthSquared()
          Return the sum of squares of all elements in the vector.
 java.lang.String getName()
           
 int getNumNondefaultElements()
          Return the number of values in the recipient
 double getQuick(int index)
          Return the value at the given index, without checking bounds
 int hashCode()
           
 boolean isDense()
           
 boolean isSequentialAccess()
           
 java.util.Iterator<Vector.Element> iterateNonZero()
          Iterates over all non-zero elements.
 java.util.Iterator<Vector.Element> iterator()
          Iterates over all elements

* NOTE: Implementations may choose to reuse the Element returned for performance reasons, so if you need a copy of it, you should call Vector.getElement(int) for the given index

 NamedVector 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()
           
 Vector minus(Vector x)
          Return a new vector containing the element by element difference of the recipient and the argument
 double minValue()
           
 int minValueIndex()
           
 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
 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, toString, wait, wait, wait
 

Constructor Detail

NamedVector

public NamedVector()

NamedVector

public NamedVector(NamedVector other)

NamedVector

public NamedVector(Vector delegate,
                   java.lang.String name)
Method Detail

getName

public java.lang.String getName()

getDelegate

public Vector getDelegate()

hashCode

public int hashCode()
Overrides:
hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object other)
To not break transitivity with other Vectors, this does not compare name.

Overrides:
equals in class java.lang.Object

clone

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

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

asFormatString

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

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

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

assign

public Vector assign(Vector other,
                     BinaryFunction 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 BinaryFunction to apply
Returns:
the modified receiver

assign

public Vector assign(BinaryFunction 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 BinaryFunction

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

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

isDense

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

isSequentialAccess

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

iterator

public java.util.Iterator<Vector.Element> iterator()
Description copied from interface: Vector
Iterates over all elements

* NOTE: Implementations may choose to reuse the Element returned for performance reasons, so if you need a copy of it, you should call Vector.getElement(int) for the given index

Specified by:
iterator in interface java.lang.Iterable<Vector.Element>
Specified by:
iterator in interface Vector
Returns:
An Iterator over all elements

iterateNonZero

public java.util.Iterator<Vector.Element> iterateNonZero()
Description copied from interface: Vector
Iterates over all non-zero elements.

NOTE: Implementations may choose to reuse the Element returned for performance reasons, so if you need a copy of it, you should call Vector.getElement(int) for the given index

Specified by:
iterateNonZero in interface Vector
Returns:
An Iterator over all non-zero elements

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

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

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 NamedVector 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

minus

public Vector minus(Vector x)
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:
x - 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

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)

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

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

getNumNondefaultElements

public int getNumNondefaultElements()
Description copied from interface: Vector
Return the number of values in the recipient

Specified by:
getNumNondefaultElements in interface Vector
Returns:
an int

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

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

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

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

aggregate

public double aggregate(BinaryFunction aggregator,
                        UnaryFunction 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 postive 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,
                        BinaryFunction aggregator,
                        BinaryFunction 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
Returns:
the final aggregation

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

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

addTo

public void addTo(Vector v)
Description copied from interface: Vector
Add the elements to the other vector and results are stored in that vector.

Specified by:
addTo in interface Vector


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