util.h File Reference

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Enumerations
enum	DataFormat { COMPLEX = 0, REAL }
	Result data format for FST functions. More...

Functions
int	IndexOfHarmonicCoeff (const int, const int, const int)
	Gives the position of the coefficient f-hat(m,l) in the one-row array. More...
void	TransMult (double *, double *, double *, double *, double *, double *, const int)
	Multiplies harmonic coefficients of a function and a filter. More...

Enumeration Type Documentation

DataFormat

enum DataFormat

Result data format for FST functions.

DataFormat is used in FST functions (e.g. FSTSemiMemo()) to determine samples' data format.

Enumerator
COMPLEX	Data is complex.
REAL	Data is real.

Definition at line 10 of file util.h.

Function Documentation

IndexOfHarmonicCoeff()

int IndexOfHarmonicCoeff	(	const int	m,
		const int	l,
		const int	bw
	)

Gives the position of the coefficient f-hat(m,l) in the one-row array.

Returns the position of the coefficient f-hat(m,l) in the one-row array with the spherical coefficients. It helps to preserve the symmetry that the coefficients have:

f-hat(l,-m) = (-1)^m * conjugate( f-hat(l,m) )

Parameters

m	order
l	degree
bw	bandwidth

Definition at line 42 of file util.c.

TransMult()

void TransMult	(	double *	rdatacoeffs,
		double *	idatacoeffs,
		double *	rfiltercoeffs,
		double *	ifiltercoeffs,
		double *	rres,
		double *	ires,
		const int	bw
	)

Multiplies harmonic coefficients of a function and a filter.

See convolution theorem of Driscoll and Healy for details.

Parameters

rdatacoeffs	real data coefficients
idatacoeffs	imaginary data coefficients
rfiltercoeffs	real filter coefficients
ifiltercoeffs	imaginary filter coefficients
rres	array of real result
ires	array of imaginary result
bw	bandwidth of problem

Note

datacoeffs should be output of an SHT (e.g. FSTSemiMemo())

filtercoeffs should be output of an SHT (e.g. FZTSemiMemo())

All arrays must be of length bw*bw

Definition at line 68 of file util.c.