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

Constructor Summary

Constructors
Constructor Description

DoubleTableFNT()
Default constructor.

Method Summary

All Methods Instance Methods Concrete Methods
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 Detail
  - DoubleTableFNT
```
public DoubleTableFNT()
```
    Default constructor.
- Method Detail
  - 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