Package org.apfloat.internal

Class DoubleTableFNT

java.lang.Object

org.apfloat.internal.DoubleElementaryModMath

org.apfloat.internal.DoubleModMath

org.apfloat.internal.DoubleTableFNT

Direct Known Subclasses:

DoubleNTTStepStrategy, DoubleTableFNTStrategy

public class DoubleTableFNT
extends DoubleModMath

Fast Number Theoretic Transform that uses lookup tables for powers of n:th root of unity and permutation indexes.

All access to this class must be externally synchronized.

Since:

1.7.0

Version:

1.7.0

Author:

Mikko Tommila

Constructor Summary

Constructors

Constructor	Description
DoubleTableFNT()	Default constructor.

Method Summary

Modifier and Type	Method	Description
void	inverseTableFNT(ArrayAccess arrayAccess, double[] wTable, int[] permutationTable)	Inverse (Cooley-Tukey) fast Number Theoretic Transform.
void	tableFNT(ArrayAccess arrayAccess, double[] wTable, int[] permutationTable)	Forward (Sande-Tukey) fast Number Theoretic Transform.

Methods inherited from class org.apfloat.internal.DoubleModMath

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

Methods inherited from class org.apfloat.internal.DoubleElementaryModMath

getModulus, modAdd, modMultiply, modSubtract, setModulus

Methods inherited from class java.lang.Object

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

Constructor Details

DoubleTableFNT

public DoubleTableFNT()

Default constructor.

Method Details

tableFNT

public void tableFNT(ArrayAccess arrayAccess,
 double[] wTable,
 int[] permutationTable)
              throws ApfloatRuntimeException

Forward (Sande-Tukey) fast Number Theoretic Transform. Data length must be a power of two.

Parameters:

arrayAccess - The data array to transform.

wTable - Table of powers of n:th root of unity w modulo the current modulus.

permutationTable - Table of permutation indexes, or null if the data should not be permuted.

Throws:

ApfloatRuntimeException

inverseTableFNT

public void inverseTableFNT(ArrayAccess arrayAccess,
 double[] wTable,
 int[] permutationTable)
                     throws ApfloatRuntimeException

Inverse (Cooley-Tukey) fast Number Theoretic Transform. Data length must be a power of two.

Parameters:

arrayAccess - The data array to transform.

wTable - Table of powers of n:th root of unity w modulo the current modulus.

permutationTable - Table of permutation indexes, or null if the data should not be permuted.

Throws:

ApfloatRuntimeException