org.apache.mahout.math

Class AbstractMatrix.TransposeViewVector

java.lang.Object

org.apache.mahout.math.AbstractVector

org.apache.mahout.math.AbstractMatrix.TransposeViewVector

All Implemented Interfaces:

Cloneable, Vector

Enclosing class:

AbstractMatrix

protected static class AbstractMatrix.TransposeViewVector
extends AbstractVector

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.mahout.math.AbstractVector

AbstractVector.LocalElement

Nested classes/interfaces inherited from interface org.apache.mahout.math.Vector

Vector.Element

Field Summary

Fields inherited from class org.apache.mahout.math.AbstractVector

lengthSquared

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractMatrix.TransposeViewVector(Matrix m, int offset)
protected	AbstractMatrix.TransposeViewVector(Matrix m, int offset, boolean rowToColumn)

Method Summary

Methods

Modifier and Type	Method and Description
Vector	clone() Return a copy of the recipient
Vector.Element	getElement(int i) 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	getLookupCost() Gets an estimate of the cost (in number of operations) it takes to lookup a random element in this vector.
int	getNumNondefaultElements() TODO: currently I don't know of an efficient way to getVector this value correctly.
double	getQuick(int index) Return the value at the given index, without checking bounds
boolean	isAddConstantTime() Return true iff adding a new (nonzero) element takes constant time for this vector.
boolean	isDense()
boolean	isSequentialAccess()
Iterator<Vector.Element>	iterateNonZero() Currently delegates to iterator().
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 AbstractVector.getElement(int) for the given index
Vector	like() Return an empty vector of the same underlying class as the receiver
Vector	like(int cardinality) Return a new empty vector of the same underlying class as the receiver with given cardinality
protected Matrix	matrixLike(int rows, int columns) Subclasses must override to return an appropriately sparse or dense result
void	mergeUpdates(OrderedIntDoubleMapping updates) Used internally by assign() to update multiple indices and values at once.
protected Vector	newVector(int cardinality)
void	setQuick(int index, double value) Set the value at the given index, without checking bounds

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

aggregate, aggregate, all, asFormatString, assign, assign, assign, assign, assign, assign, createOptimizedCopy, cross, divide, dot, dotSelf, equals, get, getDistanceSquared, getLengthSquared, getNumNonZeroElements, hashCode, incrementQuick, invalidateCachedLength, logNormalize, logNormalize, logNormalize, maxValue, maxValueIndex, minus, minValue, minValueIndex, nonZeroes, norm, normalize, normalize, plus, plus, set, size, sparseVectorToString, times, times, toString, toString, viewPart, zSum

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractMatrix.TransposeViewVector

protected AbstractMatrix.TransposeViewVector(Matrix m,
                                  int offset)

AbstractMatrix.TransposeViewVector

protected AbstractMatrix.TransposeViewVector(Matrix m,
                                  int offset,
                                  boolean rowToColumn)

Method Detail

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 AbstractVector

Returns:

a new Vector

isDense

public boolean isDense()

Returns:

true iff this implementation should be considered dense -- that it explicitly represents every value

isSequentialAccess

public boolean isSequentialAccess()

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.

matrixLike

protected Matrix matrixLike(int rows,
                int columns)

Description copied from class: AbstractVector

Subclasses must override to return an appropriately sparse or dense result

Specified by:

matrixLike in class AbstractVector

Parameters:

rows - the row cardinality

columns - the column cardinality

Returns:

a Matrix

iterator

public Iterator<Vector.Element> iterator()

Description copied from class: AbstractVector

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 AbstractVector.getElement(int) for the given index

Specified by:

iterator in class AbstractVector

Returns:

An Iterator over all elements

iterateNonZero

public Iterator<Vector.Element> iterateNonZero()

Currently delegates to iterator(). TODO: This could be optimized to at least skip empty rows if there are many of them.

Specified by:

iterateNonZero in class AbstractVector

Returns:

an iterator (currently dense).

getElement

public Vector.Element getElement(int i)

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

Overrides:

getElement in class AbstractVector

Parameters:

i - Index of the Vector.Element required

Returns:

The Vector.Element Object

mergeUpdates

public void mergeUpdates(OrderedIntDoubleMapping updates)

Used internally by assign() to update multiple indices and values at once. Only really useful for sparse vectors (especially SequentialAccessSparseVector).

If someone ever adds a new type of sparse vectors, this method must merge (index, value) pairs into the vector.

Parameters:

updates - a mapping of indices to values to merge in the vector.

getQuick

public double getQuick(int index)

Description copied from interface: Vector

Return the value at the given index, without checking bounds

Parameters:

index - an int index

Returns:

the double at the index

setQuick

public void setQuick(int index,
            double value)

Description copied from interface: Vector

Set the value at the given index, without checking bounds

Parameters:

index - an int index into the receiver

value - a double value to set

newVector

protected Vector newVector(int cardinality)

like

public Vector like()

Description copied from interface: Vector

Return an empty vector of the same underlying class as the receiver

Returns:

a Vector

like

public Vector like(int cardinality)

Description copied from interface: Vector

Return a new empty vector of the same underlying class as the receiver with given cardinality

Returns:

getNumNondefaultElements

public int getNumNondefaultElements()

TODO: currently I don't know of an efficient way to getVector this value correctly.

Returns:

the number of nonzero entries

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.

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.

isAddConstantTime

public boolean isAddConstantTime()

Description copied from interface: Vector

Return true iff adding a new (nonzero) element takes constant time for this vector.