com.tdunning.math.stats

Class Simple64

java.lang.Object

com.tdunning.math.stats.Simple64

public class Simple64
extends Object

Very simple variable byte encoding that always uses 64bit units. The idea is that the next few values are smashed into 64 bits using a few bits to indicate how they are fitted in and the rest of the bits to fit each value into equal-sized chunks. In this encoding, 4 bits are used to indicate how the remaining 60 bits are divided. The possible ways are shown in the following table:

Size codes for Simple64 compression

Code	Arrangement
14	1 X 60BITS
13	2 X 30BITS
12	3 X 20BITS
11	4 X 15BITS
10	5 X 12BITS
9	6 X 10BITS
8	7 X 8BITS
7	8 X 7BITS
6	10 X 6BITS
5	12 X 5BITS
4	15 X 4BITS
3	20 X 3BITS
2	30 X 2BITS
1	60 X 1BITS

Constructor Summary

Constructors

Constructor and Description
Simple64()

Method Summary

Modifier and Type	Method and Description
int	add(long v, long[] out)
static void	compress(LongBuffer compressedBuffer, long[] unCompressedData, int offset, int size)
static int	decompress(LongBuffer compressedBuffer, long[] unCompressedData)

Methods inherited from class java.lang.Object

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

Constructor Detail

Simple64

public Simple64()

Method Detail

add

public int add(long v,
               long[] out)

compress

public static void compress(LongBuffer compressedBuffer,
                            long[] unCompressedData,
                            int offset,
                            int size)

decompress

public static int decompress(LongBuffer compressedBuffer,
                             long[] unCompressedData)