ai.libs.jaicore.basic

Class MathExt

java.lang.Object

ai.libs.jaicore.basic.MathExt

public class MathExt
extends java.lang.Object

A util class for some simple mathematical helpers.

Method Summary

Modifier and Type	Method and Description
static long	binomial(int n, int k) Computes the binomial of n choose k.
static int	doubleFactorial(int k) Computes the double factorial of k, i.e. k!!.
static java.util.Set<java.lang.Integer>	getIntegersFromTo(int from, int to) Gets a list of all integers for a certain range "from" to "to" (both inclusively).
static double	round(double d, int precision) Rounds a double value to a certain number of decimal places.

Methods inherited from class java.lang.Object

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

Method Detail

binomial

public static long binomial(int n,
                            int k)

Computes the binomial of n choose k.

Parameters:

n - The size of the whole set.

k - The size of the chosen subset.

Returns:

The number of all possible combinations of how to choose k elements from a set of n elements.

getIntegersFromTo

public static java.util.Set<java.lang.Integer> getIntegersFromTo(int from,
                                                                 int to)

Gets a list of all integers for a certain range "from" to "to" (both inclusively).

Parameters:

from - The lower bound (included).

to - The upper bound (included).

Returns:

The set of all integers of the specified range.

doubleFactorial

public static int doubleFactorial(int k)

Computes the double factorial of k, i.e. k!!.

Parameters:

k - The k for which to compute the double factorial for.

Returns:

The double factorial for the specified number k.

round

public static double round(double d,
                           int precision)

Rounds a double value to a certain number of decimal places.

Parameters:

d - The value to be rounded.

precision - The number of decimal places.

Returns:

The rounded value.