water.util

Class MRUtils

java.lang.Object

water.util.MRUtils

public class MRUtils
extends java.lang.Object

Constructor Summary

Constructors

Constructor and Description
MRUtils()

Method Summary

Methods

Modifier and Type	Method and Description
static Frame	sampleFrame(Frame fr, long rows, long seed) Sample rows from a frame.
static Frame	shuffleFramePerChunk(Frame fr, long seed) Row-wise shuffle of a frame (only shuffles rows inside of each chunk)

Methods inherited from class java.lang.Object

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

Constructor Detail

MRUtils

public MRUtils()

Method Detail

sampleFrame

public static Frame sampleFrame(Frame fr,
                long rows,
                long seed)

Sample rows from a frame. Can be unlucky for small sampling fractions - will continue calling itself until at least 1 row is returned.

Parameters:

fr - Input frame

rows - Approximate number of rows to sample (across all chunks)

seed - Seed for RNG

Returns:

Sampled frame

shuffleFramePerChunk

public static Frame shuffleFramePerChunk(Frame fr,
                         long seed)

Row-wise shuffle of a frame (only shuffles rows inside of each chunk)

Parameters:

fr - Input frame

Returns:

Shuffled frame