org.apache.storm.loadgen

Class NormalDistStats

java.lang.Object

org.apache.storm.loadgen.NormalDistStats

All Implemented Interfaces:

Serializable

public class NormalDistStats
extends Object
implements Serializable

Stats related to something with a normal distribution, and a way to randomly simulate it.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
double	max
double	mean
double	min
double	stddev

Constructor Summary

Constructors

Constructor and Description
NormalDistStats(double mean, double stddev, double min, double max) A Constructor for the pre computed stats.
NormalDistStats(List<Double> values) Create an instance of this from a list of values.

Method Summary

Modifier and Type	Method and Description
static NormalDistStats	fromConf(Map<String,Object> conf) Read the stats from a config.
static NormalDistStats	fromConf(Map<String,Object> conf, Double def) Read the stats from a config.
double	nextRandom(Random rand) Generate a random number that follows the statistical distribution.
NormalDistStats	scaleBy(double v) Scale the stats by v.
Map<String,Object>	toConf() Return this as a config.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

mean

public final double mean

stddev

public final double stddev

min

public final double min

max

public final double max

Constructor Detail

NormalDistStats

public NormalDistStats(List<Double> values)

Create an instance of this from a list of values. The metrics will be computed from the values.

Parameters:

values - the values to compute metrics from.

NormalDistStats

public NormalDistStats(double mean,
                       double stddev,
                       double min,
                       double max)

A Constructor for the pre computed stats.

Parameters:

mean - the mean of the values.

stddev - the standard deviation of the values.

min - the min of the values.

max - the max of the values.

Method Detail

fromConf

public static NormalDistStats fromConf(Map<String,Object> conf)

Read the stats from a config.

Parameters:

conf - the config.

Returns:

the corresponding stats.

fromConf

public static NormalDistStats fromConf(Map<String,Object> conf,
                                       Double def)

Read the stats from a config.

Parameters:

conf - the config.

def - the default mean.

Returns:

the corresponding stats.

toConf

public Map<String,Object> toConf()

Return this as a config.

Returns:

the config version of this.

nextRandom

public double nextRandom(Random rand)

Generate a random number that follows the statistical distribution.

Parameters:

rand - the random number generator to use

Returns:

the next number that should follow the statistical distribution.

toString

public String toString()

Overrides:

toString in class Object

scaleBy

public NormalDistStats scaleBy(double v)

Scale the stats by v. This is not scaling everything proportionally. We don’t want the stddev to increase so instead we scale the mean and shift everything up or down by the same amount.

Parameters:

v - the amount to scale by 1.0 is nothing 0.5 is half.

Returns:

a copy of this with the needed adjustments.