com.antelmann.util
Class MyMath

java.lang.Object
  com.antelmann.util.MyMath

public final class MyMath
extends Object

some math related static functions including some useful statistics functions

Author:

Holger Antelmann

Field Summary

double

FIB the neares quotient of Fibonacci numbers as double

Method Summary

static double	average(double... population) returns mean(population)
static double	centimeterToInch(double centimeter) just for convenient reference
static double	inchToCentimeter(double inch) just for convenient reference
static double	max(double... value) returns the greatest element out of the given array
static long	max(long... value) returns the greatest element out of the given array
static double	maxIndex(double... value) returns the index of the greatest element from the given array
static double	mean(double... population) returns the mean of the population
static double	median(double... population) returns the median of the given population
static double	min(double... value) returns the smallest element out of the given array
static double	minIndex(double... value) returns the index of the smallest element from the given array
static double	range(double... population) returns the difference between the max and the min element
static double	sigmoid(double x) produces a double between 0 and 1 with (sigmoid(0.5) == 0) being true
static double	sigmoid(double x, double flatteningFactor) sigmoid(double x) is the same as sigmoid(double x, 1), large flatteningFactor flattens the curve
static double	softmax(int index, double... x) produces a double between 0 and 1 based on the given array x and the index that must be between (0 and x.length) For further information see also: http://www-ccs.ucsd.edu/matlab/toolbox/nnet/softmax.html
static double	standardDeviation(double... population) returns the standard deviation of the given population based on variance()
static double	stdDev(double... sample) returns the standard deviation of the given sample based on var()
static double	sum(double... population) returns the sum of the given population
static int	sumOfDigits(long number) returns the sum of all individual digits.
static double	var(double... sample) returns the variance of the given sample of a population
static double	variance(double... population) returns the variance of the given population
static double	YardToMeter(double yard) just for convenient reference

Methods inherited from class java.lang.Object

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

Field Detail

FIB

public final double FIB

the neares quotient of Fibonacci numbers as double

See Also:

Constant Field Values

Method Detail

sumOfDigits

public static int sumOfDigits(long number)

returns the sum of all individual digits. Example: sumOfDigits(123045) returns 15 (1+2+3+4+0+5).

average

public static double average(double... population)

returns mean(population)

See Also:

mean(double[])

mean

public static double mean(double... population)

returns the mean of the population

sum

public static double sum(double... population)

returns the sum of the given population

range

public static double range(double... population)

returns the difference between the max and the min element

median

public static double median(double... population)

returns the median of the given population

variance

public static double variance(double... population)

returns the variance of the given population

var

public static double var(double... sample)

returns the variance of the given sample of a population

standardDeviation

public static double standardDeviation(double... population)

returns the standard deviation of the given population based on variance()

See Also:

variance(double[] population)

stdDev

public static double stdDev(double... sample)

returns the standard deviation of the given sample based on var()

See Also:

var(double[])

max

public static double max(double... value)

returns the greatest element out of the given array

max

public static long max(long... value)

returns the greatest element out of the given array

maxIndex

public static double maxIndex(double... value)

returns the index of the greatest element from the given array

min

public static double min(double... value)

returns the smallest element out of the given array

minIndex

public static double minIndex(double... value)

returns the index of the smallest element from the given array

sigmoid

public static double sigmoid(double x)

produces a double between 0 and 1 with (sigmoid(0.5) == 0) being true

sigmoid

public static double sigmoid(double x,
                             double flatteningFactor)

sigmoid(double x) is the same as sigmoid(double x, 1), large flatteningFactor flattens the curve

softmax

public static double softmax(int index,
                             double... x)

produces a double between 0 and 1 based on the given array x and the index that must be between (0 and x.length) For further information see also: http://www-ccs.ucsd.edu/matlab/toolbox/nnet/softmax.html

centimeterToInch

public static double centimeterToInch(double centimeter)

just for convenient reference

inchToCentimeter

public static double inchToCentimeter(double inch)

just for convenient reference

YardToMeter

public static double YardToMeter(double yard)

just for convenient reference