OpenSim::Signal Class Reference

A class for signal processing. More...

#include <Signal.h>

Static Public Member Functions
static int	SmoothSpline (int aDegree, double aDeltaT, double aCutOffFrequency, int aN, double aTimes, double aSignal, double *rFilteredSignal)
	Generalized, cross-validatory spline smoothing (Adv.
static int	LowpassIIR (double aDeltaT, double aCutOffFrequency, int aN, double aSignal, double rFilteredSignal)
	3rd ORDER LOWPASS IIR BUTTERWORTH DIGITAL DIGITAL FILTER
static int	LowpassFIR (int aOrder, double aDeltaT, double aCutoffFrequency, int aN, double aSignal, double rFilteredSignal)
	LOWPASS FIR NONRECURSIVE DIGITAL FILTER.
static int	BandpassFIR (int aOrder, double aDeltaT, double aLowFrequency, double aHighFrequency, int aN, double aSignal, double aFilteredSignal)
	BANDPASS FIR NONRECURSIVE DIGITAL FILTER.
static double *	Pad (int aPad, int aN, const double aSignal[])
	Pad a signal with a specified number of data points.
static void	Pad (int aPad, OpenSim::Array< double > &aSignal)
	Pad a signal with a specified number of data points.
static int	ReduceNumberOfPoints (double aDistance, Array< double > &rTime, Array< double > &rSignal)
	Remove points in a signal based on the angle between adjacent segments in the signal.
static double	sinc (double x)
	SINC(X) = SIN(X) / X.
static double	hamming (int k, int M)
	Hamming Window- dampens gibs phenominon infiltering functions.

Detailed Description

A class for signal processing.

Member Function Documentation

int Signal::BandpassFIR	(	int	M,
		double	T,
		double	f1,
		double	f2,
		int	N,
		double *	sig,
		double *	sigf
	)			`[static]`

BANDPASS FIR NONRECURSIVE DIGITAL FILTER.

Note that sig and sigf must point to distinct locations in memory which do not overlap.

PARAMETERS

Parameters:

	M	Order of filter (should be 30 or greater).
	T	Sample interval in seconds. lowend cutoff frequency in Hz highend cutoff frequency in Hz
	N	Number of data points in the signal.
	sig	The sampled signal.
	sigf	The filtered signal.

Returns:: 0 on success, and -1 on failure.

double Signal::hamming	(	int	k,
		int	M
	)			`[static]`

Hamming Window- dampens gibs phenominon infiltering functions.

int Signal::LowpassFIR	(	int	M,
		double	T,
		double	f,
		int	N,
		double *	sig,
		double *	sigf
	)			`[static]`

LOWPASS FIR NONRECURSIVE DIGITAL FILTER.

It is permissible for sig and sigf to be the same array or overlap.

PARAMETERS

Parameters:

	M	Order of filter (should be 30 or greater).
	T	Sample interval in seconds.
	f	Cutoff frequency in Hz.
	N	Number of data points in the signal.
	sig	The sampled signal.
	sigf	The filtered signal.

Returns:: 0 on success, and -1 on failure.

int Signal::LowpassIIR	(	double	T,
		double	fc,
		int	N,
		double *	sig,
		double *	sigf
	)			`[static]`

3rd ORDER LOWPASS IIR BUTTERWORTH DIGITAL DIGITAL FILTER

It is assumed that enough memory is allocated at sigf. Note also that the first and last three data points are not filtered.

Parameters:

	T	Sample interval in seconds.
	fc	Cutoff frequency in Hz.
	N	Number of data points in the signal.
	sig	The sampled signal.
	sigf	The filtered signal.

Returns:: 0 on success, and -1 on failure.

void Signal::Pad	(	int	aPad,
		OpenSim::Array< double > &	aSignal
	)			`[static]`

Pad a signal with a specified number of data points.

The signal is prepended and appended with a reflected and negated portion of the signal of the appropriate size so as to preserve the value and slope of the signal.

PARAMETERS

Parameters:

	aPad	Size of the pad-- number of points to prepend and append.
	rSignal	Signal to be padded.

double * Signal::Pad	(	int	aPad,
		int	aN,
		const double	aSignal[]
	)			`[static]`

Pad a signal with a specified number of data points.

The signal is prepended and appended with a reflected and negated portion of the signal of the appropriate size so as to preserve the value and slope of the signal.

PARAMETERS

Parameters:

	aPad	Size of the pad-- number of points to prepend and append.
	aN	Number of data points in the signal.
	aSignal	Signal to be padded.

Returns:: Padded signal. The size is aN + 2*aPad. NULL is returned on an error. The caller is responsible for deleting the returned array.

int Signal::ReduceNumberOfPoints	(	double	aDistance,
		Array< double > &	rTime,
		Array< double > &	rSignal
	)			`[static]`

Remove points in a signal based on the angle between adjacent segments in the signal.

The end points of the signal are always retained.

Parameters:

	aAngle	If the angle between two adjacent segments is less than aAngle the point in common between the two segments is removed. This is evaluate for each point in the signal.
	rTime	Array of time values. This array is altered.
	rSignal	Array of signal values. This array is altered.

Returns:: Number of points removed.

double Signal::sinc ( double x ) [static]

SINC(X) = SIN(X) / X.

Returns:: sin(x)/x.

int Signal::SmoothSpline	(	int	degree,
		double	T,
		double	fc,
		int	N,
		double *	times,
		double *	sig,
		double *	sigf
	)			`[static]`

Generalized, cross-validatory spline smoothing (Adv.

Engng. Softw. 8:104-113)

Parameters:

	degree	Degree of the spline.
	T	Sample interval in seconds.
	fc	Cutoff frequency in Hz.
	N	Number of data points in the signal.
	times	The times for a specified signal samples.
	sig	The sampled signal.
	sigf	The filtered signal.

Returns:: 0 on success, and -1 on failure.

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

OpenSim/Common/Signal.h
OpenSim/Common/Signal.cpp

OpenSim::Signal Class Reference

Static Public Member Functions

Detailed Description

Member Function Documentation