io.cdap.wrangler.sampling

Class MathUtils

java.lang.Object

io.cdap.wrangler.sampling.MathUtils

public final class MathUtils
extends Object

Collection of simple mathematical routines.

Method Summary

Modifier and Type	Method and Description
static int	bitMix(int in) Bit-mixing for pseudo-randomization of integers (e.g., to guard against bad hash functions).
static int	murmurHash(int code) This function hashes an integer value.

Methods inherited from class java.lang.Object

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

Method Detail

murmurHash

public static int murmurHash(int code)

This function hashes an integer value. It is crucial to use different hash functions to partition data and the internal partitioning of data structures. This hash function is intended for partitioning across machines.

Parameters:

code - The integer to be hashed.

Returns:

The non-negative hash code for the integer.

bitMix

public static int bitMix(int in)

Bit-mixing for pseudo-randomization of integers (e.g., to guard against bad hash functions). Implementation is from Murmur's 32 bit finalizer.

Parameters:

in - the input value

Returns:

the bit-mixed output value