com.ericlam.mc.rankcal.utils

Class AdvMath

java.lang.Object

com.ericlam.mc.rankcal.utils.AdvMath

public final class AdvMath
extends java.lang.Object

AdvMath utils

Method Summary

Modifier and Type	Method and Description
static double	computeErr(double total, double a, double b)
static boolean	contain(double[] row, double[] contain)
static long	count(double[][] tables, double[] set)
static long	count(double[] row, double value)
static double	entropy(double total, double a, double b)
static int	getLength(double num) return the length of that number
static int	getLength(long num) return the length of that number
static double	gini(double total, double a, double b)
static double	log2(double n)
static double	round(int f, double num) when over 0.5, round up, else round down
static double	roundCil(int f, double num) round up
static double	roundFlr(int f, double num) round down
static java.util.List<java.lang.Double>	toDoubleList(double[] arr)
static double[]	toHashDoubleArray(java.lang.Object[] arr)

Methods inherited from class java.lang.Object

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

Method Detail

getLength

public static int getLength(long num)

return the length of that number

Parameters:

num - num

Returns:

number length

getLength

public static int getLength(double num)

return the length of that number

Parameters:

num - num

Returns:

number length

round

public static double round(int f,
                           double num)

when over 0.5, round up, else round down

Parameters:

f - round length

num - value

Returns:

rounded value

roundCil

public static double roundCil(int f,
                              double num)

round up

Parameters:

f - round number

num - value

Returns:

rounded value

roundFlr

public static double roundFlr(int f,
                              double num)

round down

Parameters:

f - round number

num - value

Returns:

rounded value

contain

public static boolean contain(double[] row,
                              double[] contain)

Parameters:

row - Set

contain - SubSet

Returns:

Set contain subset

count

public static long count(double[] row,
                         double value)

Parameters:

row - Set

value - value

Returns:

how many times that value contain in Set

count

public static long count(double[][] tables,
                         double[] set)

Parameters:

tables - Tables

set - SubSet

Returns:

How many tables does subset have

toDoubleList

public static java.util.List<java.lang.Double> toDoubleList(double[] arr)

Parameters:

arr - double array

Returns:

double List

toHashDoubleArray

public static double[] toHashDoubleArray(java.lang.Object[] arr)

Parameters:

arr - object array

Returns:

double array

gini

public static double gini(double total,
                          double a,
                          double b)

Parameters:

total - total

a - first item value

b - second item value

Returns:

Gini Index

entropy

public static double entropy(double total,
                             double a,
                             double b)

Parameters:

total - total value

a - first item value

b - second item value

Returns:

entropy value

computeErr

public static double computeErr(double total,
                                double a,
                                double b)

Parameters:

total - total value

a - first item value

b - second item value

Returns:

computed error rate

log2

public static double log2(double n)