com.yahoo.egads.utilities

Class StatsUtils

java.lang.Object

com.yahoo.egads.utilities.StatsUtils

public class StatsUtils
extends java.lang.Object

Provides convenience methods to return the number, arithmetic mean average, variance, minimum, median and maximum value of a list of values, and other statistical values.

Additionally, StatsUtils includes methods to get a histogram list approach to the data; each data segment includes the counts of data. For example, [1,4,5,3,1] has five segments with one data value in the first segment and five data values in the third segment.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	StatsUtils.DoubleStats Extension of Stats using the double primitive.
static class	StatsUtils.Stats An abstract class that holds the minimum, maximum, median average, quartiles one and three, and second, third and fourth central moments.

Method Summary

Modifier and Type	Method and Description
static java.util.List<java.lang.Integer>	getHistogram(java.util.List<java.lang.Double> data, int breaks) Creates a histogram of the provided data.
static java.util.List<java.lang.Integer>	getHistogramBigInt(java.util.List<java.math.BigInteger> data, int breaks) Same as getHistogram but operates on BigIntegers.
static java.lang.Float	getMean(java.lang.Float[] data)
static java.lang.Float	getSD(java.lang.Float[] data, java.lang.Float mean)
static StatsUtils.DoubleStats	quickStatsDouble(java.util.List<java.lang.Double> l)
static java.util.List<java.lang.Double>	rank(java.util.List<java.lang.Double> data)
static double[]	swilk(java.util.List<java.lang.Double> d) Runs the Shapiro-Wilk test on a list of double values.

Methods inherited from class java.lang.Object

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

Method Detail

getMean

public static java.lang.Float getMean(java.lang.Float[] data)

getSD

public static java.lang.Float getSD(java.lang.Float[] data,
                                    java.lang.Float mean)

quickStatsDouble

public static StatsUtils.DoubleStats quickStatsDouble(java.util.List<java.lang.Double> l)

Returns:

the number, average, variance, min, median and max of a list of Integers

getHistogram

public static java.util.List<java.lang.Integer> getHistogram(java.util.List<java.lang.Double> data,
                                                             int breaks)

Creates a histogram of the provided data.

Parameters:

data - list of observations

breaks - number of breaks in the histogram

Returns:

List of integer values size of the breaks

getHistogramBigInt

public static java.util.List<java.lang.Integer> getHistogramBigInt(java.util.List<java.math.BigInteger> data,
                                                                   int breaks)

Same as getHistogram but operates on BigIntegers.

rank

public static java.util.List<java.lang.Double> rank(java.util.List<java.lang.Double> data)

Returns:

list of sample ranks

swilk

public static double[] swilk(java.util.List<java.lang.Double> d)

Runs the Shapiro-Wilk test on a list of double values.

Returns:

an array of size two if everything goes well, or null if there's an error.