C# Class IntXLib.FhtHelper

Contains helping methods for work with FHT (Fast Hartley Transform). FHT is a better alternative of FFT (Fast Fourier Transform) - at least for IntX.

ファイルを表示 Open project: devoyster/IntXLib

Public Methods

Method	Description
ConvertDigitsToDouble ( uint digits, uint length, uint newLength ) : double[]	Converts IntX digits into real representation (used in FHT).
ConvertDoubleToDigits ( double array, uint length, uint digitsLength, uint digitsRes ) : void	Converts real digits representation (result of FHT) into usual IntX digits.
Fht ( double array, uint length ) : void	Performs FHT "in place" for given double[] array.
Fht ( double slice, uint length, int lengthLog2 ) : void	Performs FHT "in place" for given double[] array slice.
MultiplyFhtResults ( double data, double data2, uint length ) : void	Multiplies two FHT results and stores multiplication in first one.
ReverseFht ( double array, uint length ) : void	Performs FHT reverse "in place" for given double[] array.
ReverseFht ( double slice, uint length, int lengthLog2 ) : void	Performs reverse FHT "in place" for given double[] array slice.

Method	Description
Fht4 ( double slice ) : void	Performs FHT "in place" for given double[] array slice. Fast version for length == 4.
FhtButterfly ( double slice1, double slice2, uint index1, uint index2, double cos, double sin ) : void	Performs "butterfly" operation for Fht(double*, uint, int).
FhtHelper ( )
FillSineTable ( double sineTable ) : void	Fills sine table for FHT.
GetInitialTrigValues ( TrigValues valuesPtr, int lengthLog2 ) : void	Initializes trigonometry values for FHT.
NextTrigValues ( TrigValues valuesPtr ) : void	Generates next trigonometry values for FHT basing on previous ones.
ReverseFht8 ( double slice ) : void	Performs reverse FHT "in place" for given double[] array slice. Fast version for length == 8.
ReverseFhtButterfly ( double slice1, double slice2, uint index1, uint index2, double cos, double sin ) : void	Performs "butterfly" operation for ReverseFht(double*, uint, int).
ReverseFhtButterfly2 ( double slice1, double slice2, uint index1, uint index2, double cos, double sin ) : void	Performs "butterfly" operation for ReverseFht(double*, uint, int). Another version.

Converts IntX digits into real representation (used in FHT).

public static ConvertDigitsToDouble ( uint digits, uint length, uint newLength ) : double[]
digits	uint	Big integer digits.
length	uint	length.
newLength	uint	Multiplication result length (must be pow of 2).
return	double[]

Converts real digits representation (result of FHT) into usual IntX digits.

public static ConvertDoubleToDigits ( double array, uint length, uint digitsLength, uint digitsRes ) : void
array	double	Real digits representation.
length	uint	length.
digitsLength	uint	New digits array length (we always do know the upper value for this array).
digitsRes	uint	Big integer digits.
return	void

Performs FHT "in place" for given double[] array.

public static Fht ( double array, uint length ) : void
array	double	Double array.
length	uint	Array length.
return	void

Performs FHT "in place" for given double[] array slice.

public static Fht ( double slice, uint length, int lengthLog2 ) : void
slice	double	Double array slice.
length	uint	Slice length.
lengthLog2	int	Log2().
return	void

Multiplies two FHT results and stores multiplication in first one.

public static MultiplyFhtResults ( double data, double data2, uint length ) : void
data	double	First FHT result.
data2	double	Second FHT result.
length	uint	FHT results length.
return	void

Performs FHT reverse "in place" for given double[] array.

public static ReverseFht ( double array, uint length ) : void
array	double	Double array.
length	uint	Array length.
return	void

Performs reverse FHT "in place" for given double[] array slice.

public static ReverseFht ( double slice, uint length, int lengthLog2 ) : void
slice	double	Double array slice.
length	uint	Slice length.
lengthLog2	int	Log2().
return	void