Module me.lemire.integercompression

Package me.lemire.integercompression.differential

Class Delta

java.lang.Object

me.lemire.integercompression.differential.Delta

public final class Delta
extends Object

Generic class to compute differential coding.

Author:

Daniel Lemire

Constructor Summary

Constructors

Constructor	Description
Delta()

Method Summary

Modifier and Type	Method	Description
static void	delta(int[] data)	Apply differential coding (in-place).
static int	delta(int[] data, int start, int length, int init)	Apply differential coding (in-place) given an initial value.
static int	delta(int[] data, int start, int length, int init, int[] out)	Compute differential coding given an initial value.
static void	fastinverseDelta(int[] data)	Undo differential coding (in-place).
static int	fastinverseDelta(int[] data, int start, int length, int init)	Undo differential coding (in-place).
static void	inverseDelta(int[] data)	Undo differential coding (in-place).

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Delta

public Delta()

Method Details

delta

public static void delta(int[] data)

Apply differential coding (in-place).

Parameters:

data - data to be modified

delta

public static int delta(int[] data,
 int start,
 int length,
 int init)

Apply differential coding (in-place) given an initial value.

Parameters:

data - data to be modified

start - starting index

length - number of integers to process

init - initial value

Returns:

next initial vale

delta

public static int delta(int[] data,
 int start,
 int length,
 int init,
 int[] out)

Compute differential coding given an initial value. Output is written to a provided array: must have length "length" or better.

Parameters:

data - data to be modified

start - starting index

length - number of integers to process

init - initial value

out - output array

Returns:

next initial vale

inverseDelta

public static void inverseDelta(int[] data)

Undo differential coding (in-place). Effectively computes a prefix sum.

Parameters:

data - to be modified.

fastinverseDelta

public static void fastinverseDelta(int[] data)

Undo differential coding (in-place). Effectively computes a prefix sum. Like inverseDelta, only faster.

Parameters:

data - to be modified

fastinverseDelta

public static int fastinverseDelta(int[] data,
 int start,
 int length,
 int init)

Undo differential coding (in-place). Effectively computes a prefix sum. Like inverseDelta, only faster. Uses an initial value.

Parameters:

data - to be modified

start - starting index

length - number of integers to process

init - initial value

Returns:

next initial value