org.apfloat.spi
Interface NTTStrategy

All Known Subinterfaces:
ParallelNTTStrategy
All Known Implementing Classes:
DoubleFactor3NTTStrategy, DoubleFactor3SixStepNTTStrategy, DoubleParallelFNTStrategy, DoubleSixStepFNTStrategy, DoubleTableFNTStrategy, DoubleTwoPassFNTStrategy, FloatFactor3NTTStrategy, FloatFactor3SixStepNTTStrategy, FloatParallelFNTStrategy, FloatSixStepFNTStrategy, FloatTableFNTStrategy, FloatTwoPassFNTStrategy, IntFactor3NTTStrategy, IntFactor3SixStepNTTStrategy, IntParallelFNTStrategy, IntSixStepFNTStrategy, IntTableFNTStrategy, IntTwoPassFNTStrategy, LongFactor3NTTStrategy, LongFactor3SixStepNTTStrategy, LongParallelFNTStrategy, LongSixStepFNTStrategy, LongTableFNTStrategy, LongTwoPassFNTStrategy

public interface NTTStrategy

Number Theoretic Transform (NTT) strategy. An implementing class could be e.g.

Note: an implementing transformation class is required only to be able to perform an inverse transform on data transformed by the same class, not by any other class.

Version:
1.0
Author:
Mikko Tommila

Method Summary
 long getTransformLength(long size)
          Return the supported transform length for the specified data size.
 void inverseTransform(DataStorage dataStorage, int modulus, long totalTransformLength)
          Perform an inverse transform on the data.
 void transform(DataStorage dataStorage, int modulus)
          Perform a forward transform on the data.
 

Method Detail

transform

void transform(DataStorage dataStorage,
               int modulus)
               throws ApfloatRuntimeException
Perform a forward transform on the data.

Multiple moduli can be used, if the convolution algorithm uses the Chinese Remainder Theorem to calculate the final result.

Parameters:
dataStorage - The data to be transformed.
modulus - Number of modulus to use (in case the transform supports multiple moduli).
Throws:
ApfloatRuntimeException

inverseTransform

void inverseTransform(DataStorage dataStorage,
                      int modulus,
                      long totalTransformLength)
                      throws ApfloatRuntimeException
Perform an inverse transform on the data.

Multiple moduli can be used, if the convolution algorithm uses the Chinese Remainder Theorem to calculate the final result.

Parameters:
dataStorage - The data to be transformed.
modulus - Number of modulus to use (in case the transform supports multiple moduli).
totalTransformLength - Total transform length; the final result elements are divided by this value.
Throws:
ApfloatRuntimeException

getTransformLength

long getTransformLength(long size)
Return the supported transform length for the specified data size.

Parameters:
size - Length of the data to be transformed.
Returns:
Length of the transform needed by this transform.