jsat.utils

Class DoubleList

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractList<Double>

jsat.utils.DoubleList

All Implemented Interfaces:

Serializable, Iterable<Double>, Collection<Double>, List<Double>

public class DoubleList
extends AbstractList<Double>
implements Serializable

Provides a modifiable implementation of a List using a double array. This provides considerable memory efficency improvements over using an ArrayList to store doubles.
Null is not allowed into the list.

Author:

Edward Raff

See Also:

Serialized Form

Field Summary

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

Constructors

Constructor and Description
DoubleList() Creates a new empty DoubleList
DoubleList(Collection<Double> c) Creates a new DoubleList containing the values of the given collection
DoubleList(int capacity) Creates a new empty DoubleList

Method Summary

Modifier and Type	Method and Description
boolean	add(double e) Performs exactly the same as add(java.lang.Double).
boolean	add(Double e)
void	add(int index, double element) Operates exactly as add(int, java.lang.Double)
void	add(int index, Double element)
void	clear()
Double	get(int index)
double[]	getBackingArray() Returns the reference to the array that backs this list.
double	getD(int index) Operates exactly as get(int)
Vec	getVecView() Obtains a view of this double list as a dense vector with equal length.
Double	remove(int index)
double	removeD(int index) Operates exactly as remove(int)
double	set(int index, double element) Operates exactly as set(int, java.lang.Double)
Double	set(int index, Double element)
int	size()
static List<Double>	unmodifiableView(double[] array, int length) Creates an returns an unmodifiable view of the given double array that requires only a small object allocation.
static DoubleList	view(double[] array, int length) Creates and returns a view of the given double array that requires only a small object allocation.

Methods inherited from class java.util.AbstractList

addAll, equals, hashCode, indexOf, iterator, lastIndexOf, listIterator, listIterator, removeRange, subList

Methods inherited from class java.util.AbstractCollection

addAll, contains, containsAll, isEmpty, remove, removeAll, retainAll, toArray, toArray, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.List

addAll, contains, containsAll, isEmpty, remove, removeAll, replaceAll, retainAll, sort, spliterator, toArray, toArray

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream

Methods inherited from interface java.lang.Iterable

forEach

Constructor Detail

DoubleList

public DoubleList()

Creates a new empty DoubleList

DoubleList

public DoubleList(int capacity)

Creates a new empty DoubleList

Parameters:

capacity - the starting internal capacity of the list

DoubleList

public DoubleList(Collection<Double> c)

Creates a new DoubleList containing the values of the given collection

Parameters:

c - the collection of values to fill this double list with

Method Detail

clear

public void clear()

Specified by:

clear in interface Collection<Double>

Specified by:

clear in interface List<Double>

Overrides:

clear in class AbstractList<Double>

size

public int size()

Specified by:

size in interface Collection<Double>

Specified by:

size in interface List<Double>

Specified by:

size in class AbstractCollection<Double>

add

public boolean add(double e)

Performs exactly the same as add(java.lang.Double).

Parameters:

e - the value to add

Returns:

true if it was added, false otherwise

add

public boolean add(Double e)

Specified by:

add in interface Collection<Double>

Specified by:

add in interface List<Double>

Overrides:

add in class AbstractList<Double>

getD

public double getD(int index)

Operates exactly as get(int)

Parameters:

index - the index of the value to get

Returns:

the value at the given index

get

public Double get(int index)

Specified by:

get in interface List<Double>

Specified by:

get in class AbstractList<Double>

set

public double set(int index,
                  double element)

Operates exactly as set(int, java.lang.Double)

Parameters:

index - the index to set

element - the value to set

Returns:

the previous value at said index

set

public Double set(int index,
                  Double element)

Specified by:

set in interface List<Double>

Overrides:

set in class AbstractList<Double>

add

public void add(int index,
                double element)

Operates exactly as add(int, java.lang.Double)

Parameters:

index - the index to add at

element - the value to add

add

public void add(int index,
                Double element)

Specified by:

add in interface List<Double>

Overrides:

add in class AbstractList<Double>

removeD

public double removeD(int index)

Operates exactly as remove(int)

Parameters:

index - the index to remove

Returns:

the value removed

remove

public Double remove(int index)

Specified by:

remove in interface List<Double>

Overrides:

remove in class AbstractList<Double>

getBackingArray

public double[] getBackingArray()

Returns the reference to the array that backs this list. Alterations to the array will be visible to the DoubelList and vise versa. The array returned may not the the same size as the value returned by size()

Returns:

the underlying array used by this DoubleList

getVecView

public Vec getVecView()

Obtains a view of this double list as a dense vector with equal length. This is a soft reference, and altering the values in the matrix with alter the double list, and vise versa.

While no error will be thrown if the size of the underlying list changes, this view should be discarded if the size of the list changes. Once the list has changed sizes, there is no guarantee on the behavior that will occur if the vector is used.

Returns:

a vector view of this list

unmodifiableView

public static List<Double> unmodifiableView(double[] array,
                                            int length)

Creates an returns an unmodifiable view of the given double array that requires only a small object allocation.

Parameters:

array - the array to wrap into an unmodifiable list

length - the number of values of the array to use, starting from zero

Returns:

an unmodifiable list view of the array

view

public static DoubleList view(double[] array,
                              int length)

Creates and returns a view of the given double array that requires only a small object allocation. Changes to the list will be reflected in the array up to a point. If the modification would require increasing the capacity of the array, a new array will be allocated - at which point operations will no longer be reflected in the original array.

Parameters:

array - the array to wrap by a DoubleList object

length - the initial length of the list

Returns:

a DoubleList backed by the given array, unless modified to the point of requiring the allocation of a new array