uk.ac.ed.inf.utils.stats
Class StatUtils

java.lang.Object
  uk.ac.ed.inf.utils.stats.StatUtils

public class StatUtils
extends java.lang.Object

Utilities to print simple histograms, percent of frequency etc

Version:

19 Jul 2008

Author:

Luna De Ferrari luna.deferrari-at-ed.ac.uk

Constructor Summary

StatUtils()

Method Summary

static java.util.TreeMap<java.lang.Integer,java.lang.Integer>	arrayFrequencies(java.lang.Integer[] numbers) Records the freqencies with which the integers appear in the array
static java.util.TreeMap<java.lang.Integer,java.lang.Double>	fromFrequencyToPercOfFrequency(java.util.TreeMap<java.lang.Integer,java.lang.Integer> frequencies) Converts a frequency from number of events to percentage over the total number of exctractions
static int	getRandomInt(int upperLimitPlusOne) Problem: generates a new Random at each call...
static java.lang.String	histogram(java.util.TreeMap<java.lang.Integer,java.lang.Integer> frequencies) Returns a frequency histogram
static java.lang.String	histogramBar(java.lang.Integer integer, java.lang.Integer frequency) Returns an histogram bar
static java.util.TreeMap<java.lang.Integer,java.lang.Integer>	paretoFrequencies(Pareto pareto, int numberOfExtractions) Extracts numbers from a pareto distribution for the given number of times and records the freqencies with which the integers have been extracted
static java.util.TreeMap<java.lang.Integer,java.lang.Integer>	vectorFrequencies(java.util.Vector<java.lang.Integer> vector) Records the freqencies with which the integers appear in the array

Methods inherited from class java.lang.Object

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

Constructor Detail

StatUtils

public StatUtils()

Method Detail

arrayFrequencies

public static java.util.TreeMap<java.lang.Integer,java.lang.Integer> arrayFrequencies(java.lang.Integer[] numbers)

Records the freqencies with which the integers appear in the array

Returns:

a map containing an integer as key and a frequency as value (frequency = number of times the integer has been extracted)

fromFrequencyToPercOfFrequency

public static java.util.TreeMap<java.lang.Integer,java.lang.Double> fromFrequencyToPercOfFrequency(java.util.TreeMap<java.lang.Integer,java.lang.Integer> frequencies)

Converts a frequency from number of events to percentage over the total number of exctractions

Parameters:

frequencies - the map of each number and the number of times it was extracted

Returns:

the map with each integer as key and the percentage of times it was extracted over the total number of extractions

getRandomInt

public static int getRandomInt(int upperLimitPlusOne)

Problem: generates a new Random at each call...

Parameters:

upperLimitPlusOne -

Returns:

histogram

public static java.lang.String histogram(java.util.TreeMap<java.lang.Integer,java.lang.Integer> frequencies)

Returns a frequency histogram

Parameters:

frequencies - a map containing an integer as key and a frequency as value (frequency = number of times the integer has been extracted)

histogramBar

public static java.lang.String histogramBar(java.lang.Integer integer,
                                            java.lang.Integer frequency)

Returns an histogram bar

Parameters:

integer -

frequency -

Returns:

an histogram bar

paretoFrequencies

public static java.util.TreeMap<java.lang.Integer,java.lang.Integer> paretoFrequencies(Pareto pareto,
                                                                                       int numberOfExtractions)

Extracts numbers from a pareto distribution for the given number of times and records the freqencies with which the integers have been extracted

Parameters:

numberOfExtractions - the number of integer extractions from a a pareto distribution

Returns:

a map containing an integer as key and a frequency as value (frequency = number of times the integer has been extracted)

vectorFrequencies

public static java.util.TreeMap<java.lang.Integer,java.lang.Integer> vectorFrequencies(java.util.Vector<java.lang.Integer> vector)

Records the freqencies with which the integers appear in the array

Returns:

a map containing an integer as key and a frequency as value (frequency = number of times the integer has been extracted)