Package org.apfloat.internal

Class DoubleCarryCRTStepStrategy

java.lang.Object

org.apfloat.internal.DoubleBaseMath

org.apfloat.internal.DoubleCRTMath

org.apfloat.internal.DoubleCarryCRTStepStrategy

All Implemented Interfaces:

Serializable, CarryCRTStepStrategy<double[]>

public class DoubleCarryCRTStepStrategy
extends DoubleCRTMath
implements CarryCRTStepStrategy<double[]>

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

All access to this class must be externally synchronized.

Since:

1.7.0

Version:

1.9.0

Author:

Mikko Tommila

See Also:

• Serialized Form

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method	Description
double[]	carry(DataStorage dataStorage, long size, long resultSize, long offset, long length, double[] results, double[] previousResults)	Propagate carries from the previous block computed with the CRT method.
double[]	crt(DataStorage resultMod0, DataStorage resultMod1, DataStorage resultMod2, DataStorage dataStorage, long size, long resultSize, long offset, long length)	Perform the 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.

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 Details

DoubleCarryCRTStepStrategy

public DoubleCarryCRTStepStrategy(int radix)

Creates a carry-CRT steps object using the specified radix.

Parameters:

radix - The radix that will be used.

Method Details

crt

public double[] crt(DataStorage resultMod0,
 DataStorage resultMod1,
 DataStorage resultMod2,
 DataStorage dataStorage,
 long size,
 long resultSize,
 long offset,
 long length)
             throws ApfloatRuntimeException

Description copied from interface: CarryCRTStepStrategy

Perform the 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 for the block of data 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].

Specified by:

crt in interface CarryCRTStepStrategy<double[]>

Parameters:

resultMod0 - The result modulo MODULUS[0].

resultMod1 - The result modulo MODULUS[1].

resultMod2 - The result modulo MODULUS[2].

dataStorage - The destination data storage of the computation.

size - The number of elements in the whole data set.

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

offset - The offset within the data for the block to be computed.

length - Length of the block to be computed.

Returns:

The carries overflowing from this block (two elements).

Throws:

ApfloatRuntimeException

carry

public double[] carry(DataStorage dataStorage,
 long size,
 long resultSize,
 long offset,
 long length,
 double[] results,
 double[] previousResults)
               throws ApfloatRuntimeException

Description copied from interface: CarryCRTStepStrategy

Propagate carries from the previous block computed with the CRT method.

Specified by:

carry in interface CarryCRTStepStrategy<double[]>

Parameters:

dataStorage - The destination data storage of the computation.

size - The number of elements in the whole data set.

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

offset - The offset within the data for the block to be computed.

length - Length of the block to be computed.

results - The carry overflow from this block (two elements).

previousResults - The carry overflow from the previous block (two elements).

Returns:

The carries overflowing from this block (two elements).

Throws:

ApfloatRuntimeException