org.apfloat.internal

Class DoubleCarryCRT

java.lang.Object

org.apfloat.internal.DoubleBaseMath

org.apfloat.internal.DoubleCRTMath

org.apfloat.internal.DoubleCarryCRT

All Implemented Interfaces:

Serializable

public class DoubleCarryCRT
extends DoubleCRTMath

Class for performing the final step of a three-modulus Number Theoretic Transform based convolution. Works for the double type.

The algorithm is parallelized for multiprocessor computers, if the data fits in memory.

The parallelization works so that the carry-CRT is done in blocks in parallel. As a final step, a second pass is done through the data set to propagate the carries from one block to the next.

Version:

1.6.1

Author:

Mikko Tommila

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
DoubleCarryCRT(int radix) Creates a carry-CRT object using the specified radix.

Method Summary

Methods

Modifier and Type	Method and Description
DataStorage	carryCRT(DataStorage resultMod0, DataStorage resultMod1, DataStorage resultMod2, long resultSize) Calculate the final result of a three-NTT convolution.
void	setParallelRunner(ParallelRunner parallelRunner) Set the parallel runner to be used when executing the CRT.

Methods inherited from class org.apfloat.internal.DoubleCRTMath

add, compare, divide, multiply, subtract

Methods inherited from class org.apfloat.internal.DoubleBaseMath

baseAdd, baseDivide, baseMultiplyAdd, baseSubtract

Methods inherited from class java.lang.Object

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

Constructor Detail

DoubleCarryCRT

public DoubleCarryCRT(int radix)

Creates a carry-CRT object using the specified radix.

Parameters:

radix - The radix that will be used.

Method Detail

carryCRT

public DataStorage carryCRT(DataStorage resultMod0,
                   DataStorage resultMod1,
                   DataStorage resultMod2,
                   long resultSize)
                     throws ApfloatRuntimeException

Calculate the final result of a three-NTT convolution.

Performs a Chinese Remainder Theorem (CRT) on each element of the three result data sets to get the result of each element modulo the product of the three moduli. Then it calculates the carries to get the final result.

Note that the return value's initial word may be zero or non-zero, depending on how large the result is.

Assumes that MODULUS[0] > MODULUS[1] > MODULUS[2].

Parameters:

resultMod0 - The result modulo MODULUS[0].

resultMod1 - The result modulo MODULUS[1].

resultMod2 - The result modulo MODULUS[2].

resultSize - The number of elements needed in the final result.

Returns:

The final result with the CRT performed and the carries calculated.

Throws:

ApfloatRuntimeException

setParallelRunner

public void setParallelRunner(ParallelRunner parallelRunner)

Set the parallel runner to be used when executing the CRT.

Parameters:

parallelRunner - The parallel runner.