Package tech.tablesaw.selection

Class BitmapBackedSelection

java.lang.Object

tech.tablesaw.selection.BitmapBackedSelection

All Implemented Interfaces:

it.unimi.dsi.fastutil.ints.IntIterable, Iterable<Integer>, Selection

public class BitmapBackedSelection
extends Object
implements Selection

A Selection implemented using bitmaps

Constructor Summary

Constructors

Constructor	Description
BitmapBackedSelection()	Constructs an empty Selection
BitmapBackedSelection(int size)	Returns a selection initialized from 0 to the given size, which cane be used for queries that exclude certain items, by first selecting the items to exclude, then flipping the bits.
BitmapBackedSelection(int[] arr)	Constructs a selection containing the elements in the given array
BitmapBackedSelection(org.roaringbitmap.RoaringBitmap bitmap)	Constructs a selection containing the elements in the given bitmap

Method Summary

Modifier and Type	Method	Description
Selection	add(int... ints)	Adds the given integers to the Selection if it is not already present, and does nothing otherwise
Selection	addRange(int start, int end)	Adds to the current bitmap all integers in [rangeStart,rangeEnd)
Selection	and(Selection otherSelection)	Intersects the receiver and otherSelection, updating the receiver
Selection	andNot(Selection otherSelection)	Implements the set difference operation between the receiver and otherSelection, after updating the receiver
Selection	clear()	Returns this selection with all its values cleared
boolean	contains(int i)	Returns true if the index i is selected in this object
boolean	equals(Object o)
Selection	flip(int rangeStart, int rangeEnd)	Returns a selection with the bits from this selection flipped over the given range
int	get(int i)	Returns the value of the ith element.
int	hashCode()
boolean	isEmpty()	Returns true if this selection has no values, and false otherwise
it.unimi.dsi.fastutil.ints.IntIterator	iterator()	Returns a fastUtil intIterator that wraps a bitmap intIterator
Selection	or(Selection otherSelection)	Implements the union of the receiver and otherSelection, updating the receiver
Selection	removeRange(long start, long end)	Removes from the current bitmap from all integers in [rangeStart,rangeEnd)
protected static Selection	selectNRowsAtRandom(int n, int max)	Returns an randomly generated selection of size N where Max is the largest possible value
int	size()	Returns the number of integers represented by this Selection
int[]	toArray()	Returns the elements of this selection as an array of ints
String	toString()
protected static Selection	with(int... rows)	Returns a Selection containing all indexes in the array
protected static Selection	withoutRange(int totalRangeStart, int totalRangeEnd, int excludedRangeStart, int excludedRangeEnd)	Returns a Selection containing all values from totalRangeStart to totalRangeEnd, except for those in the range from excludedRangeStart to excludedRangeEnd.
protected static Selection	withRange(int start, int end)	Returns a Selection containing all indexes in the range start (inclusive) to end (exclusive),

Methods inherited from interface it.unimi.dsi.fastutil.ints.IntIterable

forEach, forEach

Methods inherited from interface java.lang.Iterable

spliterator

Methods inherited from class java.lang.Object

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

Constructor Detail

BitmapBackedSelection

public BitmapBackedSelection(int size)

Returns a selection initialized from 0 to the given size, which cane be used for queries that exclude certain items, by first selecting the items to exclude, then flipping the bits.

Parameters:

size - The size The end point, exclusive

BitmapBackedSelection

public BitmapBackedSelection(int[] arr)

Constructs a selection containing the elements in the given array

BitmapBackedSelection

public BitmapBackedSelection(org.roaringbitmap.RoaringBitmap bitmap)

Constructs a selection containing the elements in the given bitmap

BitmapBackedSelection

public BitmapBackedSelection()

Constructs an empty Selection

Method Detail

removeRange

public Selection removeRange(long start,
                             long end)

Removes from the current bitmap from all integers in [rangeStart,rangeEnd)

Specified by:

removeRange in interface Selection

Parameters:

start - inclusive beginning of range

end - exclusive ending of range

flip

public Selection flip(int rangeStart,
                      int rangeEnd)

Returns a selection with the bits from this selection flipped over the given range

Specified by:

flip in interface Selection

add

public Selection add(int... ints)

Adds the given integers to the Selection if it is not already present, and does nothing otherwise

Specified by:

add in interface Selection

toString

public String toString()

Overrides:

toString in class Object

size

public int size()

Returns the number of integers represented by this Selection

Specified by:

size in interface Selection

toArray

public int[] toArray()

Returns the elements of this selection as an array of ints

Specified by:

toArray in interface Selection

and

public Selection and(Selection otherSelection)

Intersects the receiver and otherSelection, updating the receiver

Specified by:

and in interface Selection

or

public Selection or(Selection otherSelection)

Implements the union of the receiver and otherSelection, updating the receiver

Specified by:

or in interface Selection

andNot

public Selection andNot(Selection otherSelection)

Implements the set difference operation between the receiver and otherSelection, after updating the receiver

Specified by:

andNot in interface Selection

isEmpty

public boolean isEmpty()

Returns true if this selection has no values, and false otherwise

Specified by:

isEmpty in interface Selection

clear

public Selection clear()

Returns this selection with all its values cleared

Specified by:

clear in interface Selection

contains

public boolean contains(int i)

Returns true if the index i is selected in this object

Specified by:

contains in interface Selection

addRange

public Selection addRange(int start,
                          int end)

Adds to the current bitmap all integers in [rangeStart,rangeEnd)

Specified by:

addRange in interface Selection

Parameters:

start - inclusive beginning of range

end - exclusive ending of range

get

public int get(int i)

Returns the value of the ith element. For example, if there are three ints {4, 32, 71} in the selection, get(0) returns 4, get(1) returns 32, and get(2) returns 71

It can be useful if you need to iterate over the data, although there is also an iterator

Specified by:

get in interface Selection

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

iterator

public it.unimi.dsi.fastutil.ints.IntIterator iterator()

Returns a fastUtil intIterator that wraps a bitmap intIterator

Specified by:

iterator in interface it.unimi.dsi.fastutil.ints.IntIterable

Specified by:

iterator in interface Iterable<Integer>

with

protected static Selection with(int... rows)

Returns a Selection containing all indexes in the array

withRange

protected static Selection withRange(int start,
                                     int end)

Returns a Selection containing all indexes in the range start (inclusive) to end (exclusive),

withoutRange

protected static Selection withoutRange(int totalRangeStart,
                                        int totalRangeEnd,
                                        int excludedRangeStart,
                                        int excludedRangeEnd)

Returns a Selection containing all values from totalRangeStart to totalRangeEnd, except for those in the range from excludedRangeStart to excludedRangeEnd. Start values are inclusive, end values exclusive.

selectNRowsAtRandom

protected static Selection selectNRowsAtRandom(int n,
                                               int max)

Returns an randomly generated selection of size N where Max is the largest possible value