Sample Class Reference

Transform a discrete time series. More...

#include <Sample.h>

Inheritance diagram for Sample:

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Collaboration diagram for Sample:

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List of all members.

Public Member Functions
double	GetHighPassFrequency (void)
	Returns the current highpass frequency.
int	GetNativeFrequency (void)
	Returns the current native sampling frequency.
double	GetTukeyFraction (void)
	Returns the current Tukey fraction.
int	GetWorkingFrequency (void)
	Returns the current working sampling frequency.
void	SetDCRemoval (const bool aDCremove=true)
	Activates/Deactivates the DC removal.
bool	SetFrequencies (const int aNativeFrequency, const int aWorkingFrequency, const double aHighPassFrequency=0.0)
	Defines frequencies for the transformation.
bool	SetHighPassFrequency (const double aHighPassFrequency)
	Defines a highpass frequency.
bool	SetNativeFrequency (const int aNativeFrequency)
	Sets a new native sampling frequency.
bool	SetWindows (const double aTukeyFraction)
	Defines windowing properties.
bool	SetWorkingFrequency (const int aWorkingFrequency)
	Sets a new working sampling frequency.
bool	Transform (const int invectorsize, double *invector, const int outvectorsize, double *outvector)
	Transforms data.
Constructors and destructors
	Sample (const int aVerbosity=0)
	Constructor of the Sample class.
virtual	~Sample (void)
	Destructor of the Sample class.
Protected Attributes
double	fHighPassFrequency
	cutoff frequency
int	fNativeFrequency
	native sampling frequency
bool	fRemoveDC
	remove DC
double	fTukeyFraction
	window fraction
int	fVerbosity
	verbosity level
int	fWorkingFrequency
	working sampling frequency

---

Detailed Description

Transform a discrete time series.

It includes:

• DC removal
• Tukey windowing
• resampling
• frequency high-passing

Author:

Florent Robinet

---

Constructor & Destructor Documentation

Sample::Sample

(

const int

aVerbosity = 0

)

Constructor of the Sample class.

Parameters:

aVerbosity

verbosity level

Sample::~Sample

(

void

)

[virtual]

Destructor of the Sample class.

---

Member Function Documentation

double Sample::GetHighPassFrequency

(

void

)

[inline]

Returns the current highpass frequency.

int Sample::GetNativeFrequency

(

void

)

[inline]

Returns the current native sampling frequency.

double Sample::GetTukeyFraction

(

void

)

[inline]

Returns the current Tukey fraction.

int Sample::GetWorkingFrequency

(

void

)

[inline]

Returns the current working sampling frequency.

void Sample::SetDCRemoval

(

const bool

aDCremove = true

)

[inline]

Activates/Deactivates the DC removal.

The DC component is computed and is subtracted from all data samples. The final vector has a DC component equal to 0.

Parameters:

aDCremove

activate/deactivate the DC removal

bool Sample::SetFrequencies	(	const int	aNativeFrequency,
		const int	aWorkingFrequency,
		const double	aHighPassFrequency = 0.0
	)

Defines frequencies for the transformation.

It is possible to work with a sampling frequency smaller than the native frequency, often for performance reasons. It must be an integer value and a power of 2. When transformed (see Transform()), the input data are first downsampled to the working frequency with an anti-aliasing filter.

In a second step, it is possible to highpass the data. When transformed (see Transform()), the input data are highpass-filtered.

Parameters:

	aNativeFrequency	native sampling frequency [Hz]
	aWorkingFrequency	working sampling frequency [Hz]
	aHighPassFrequency	highpass frequency [Hz]

bool Sample::SetHighPassFrequency

(

const double

aHighPassFrequency

)

Defines a highpass frequency.

It is possible to highpass the data. This function sets a new highpass frequency. When transformed (see Transform()), the input data are filtered.

This function can only be called if SetFrequencies() has been previously called and if the new highpass frequency is compatible with previous frequency settings.

Parameters:

aHighPassFrequency

highpass frequency [Hz]

bool Sample::SetNativeFrequency

(

const int

aNativeFrequency

)

Sets a new native sampling frequency.

This function can only be called if SetFrequencies() has been previously called and if the new working sampling frequency is compatible with previous frequency settings.

Parameters:

aNativeFrequency

new native sampling frequency [Hz]

bool Sample::SetWindows

(

const double

aTukeyFraction

)

Defines windowing properties.

It is possible to window the input data. A Tukey window is defined by a 'Tukey fraction'. To make it clear, let's take the example of a 10% Tukey fraction. This means that the first 5% of the input data vector will be smoothly transition from 0 to 1. Similarly, the last 5% of the input data vector will be smoothly transition from 1 to 0.

Parameters:

aTukeyFraction

tukey fraction between 0 and 1

bool Sample::SetWorkingFrequency

(

const int

aWorkingFrequency

)

Sets a new working sampling frequency.

It is possible to work with a sampling frequency smaller than the native frequency, often for performance reasons. This function sets a new working frequency. It must be an integer value and a power of 2. When transformed (see Transform()), the input data are first downsampled to the working frequency with an anti-aliasing filter.

This function can only be called if SetFrequencies() has been previously called and if the new working sampling frequency is compatible with previous frequency settings.

Parameters:

aWorkingFrequency

new working sampling frequency [Hz]

bool Sample::Transform	(	const int	invectorsize,
		double *	invector,
		const int	outvectorsize,
		double *	outvector
	)

Transforms data.

The input data vector (time-domain) is transformed as previously defined: see SetFrequencies(). The input vector must have an integer duration. The memory for the output vector must be allocated with the right size before calling this function. No size check will be performed and the data size provided by the user will be trusted.

IMPORTANT: the input vector can be altered in case of presampling. Do not use after calling this function.

Parameters:

	invectorsize	input vector size (in samples)
	invector	input data vector (time-domain)
	outvectorsize	output vector size (in samples)
	outvector	output data vector (time-domain)

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Member Data Documentation

double Sample::fHighPassFrequency [protected]

cutoff frequency

int Sample::fNativeFrequency [protected]

native sampling frequency

bool Sample::fRemoveDC [protected]

remove DC

double Sample::fTukeyFraction [protected]

window fraction

int Sample::fVerbosity [protected]

verbosity level

int Sample::fWorkingFrequency [protected]

working sampling frequency

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The documentation for this class was generated from the following files:

• /afs/in2p3.fr/throng/virgo/virgoDev/SoftFlorent/GWOLLUM/v2r2/src/Streams/Sample.h
• /afs/in2p3.fr/throng/virgo/virgoDev/SoftFlorent/GWOLLUM/v2r2/src/Streams/Sample.cc