Class IntWTables

java.lang.Object

org.apfloat.internal.IntElementaryModMath

org.apfloat.internal.IntModMath

org.apfloat.internal.IntWTables

public class IntWTables
extends IntModMath

Helper class for generating and caching tables of powers of the n:th root of unity.

Since:

1.7.0

Version:

1.9.0

Field Summary

Fields

Modifier and Type	Field	Description
private static ConcurrentMap<List<Integer>, int[]>	cache

Constructor Summary

Constructors

Modifier	Constructor	Description
private	IntWTables()

Method Summary

Modifier and Type	Method	Description
private static IntModMath	getInstance(int modulus)
static int[]	getInverseWTable(int modulus, int length)	Get a table of inverses of powers of n:th root of unity.
static int[]	getWTable(int modulus, int length)	Get a table of powers of n:th root of unity.
private static int[]	getWTable(int modulus, int length, boolean isInverse)

Methods inherited from class IntModMath

createWTable, getForwardNthRoot, getInverseNthRoot, modDivide, modInverse, modPow, negate

Methods inherited from class IntElementaryModMath

getModulus, modAdd, modMultiply, modSubtract, setModulus

Methods inherited from class Object

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

Field Details

cache

private static ConcurrentMap<List<Integer>, int[]> cache

Constructor Details

IntWTables

private IntWTables()

Method Details

getWTable

public static int[] getWTable(int modulus,
 int length)

Get a table of powers of n:th root of unity.

Parameters:

modulus - The index of the modulus to be used.

length - The length of the table to be returned, i.e. n.

Returns:

The table of powers of the n:th root of unity.

getInverseWTable

public static int[] getInverseWTable(int modulus,
 int length)

Get a table of inverses of powers of n:th root of unity.

Parameters:

modulus - The index of the modulus to be used.

length - The length of the table to be returned, i.e. n.

Returns:

The table of inverses of powers of the n:th root of unity.

getWTable

private static int[] getWTable(int modulus,
 int length,
 boolean isInverse)

getInstance

private static IntModMath getInstance(int modulus)