PeakTracking Class Reference

Algorithm to find peak trajectories in vectors of Complex values representing FFT, given peak positions and peak magnitudes. More...

#include <PeakTracking.h>

List of all members.

Public Member Functions
	PeakTracking (int trajectoryCount=20, Real maximumFrequencyChange=3.0, int silentFrameCount=3)
	~PeakTracking ()
void	process (const MatrixXC &ffts, const MatrixXR &peakPositions, const MatrixXR &peakMagnitudes, MatrixXR *trajectoryPositions, MatrixXR *trajectoryMagnitudes)
int	trajectoryCount () const
void	setTrajectoryCount (int count, bool callSetup=true)
Real	maximumFrequencyChange () const
void	setMaximumFrequencyChange (Real change, bool callSetup=true)
int	silentFrameCount () const
void	setSilentFrameCount (int count, bool callSetup=true)

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Detailed Description

Algorithm to find peak trajectories in vectors of Complex values representing FFT, given peak positions and peak magnitudes.

The algorithm finds a maximum number of peak trajectories and returns the positions of the trajectory positions (in fractional index units) and the trajectory magnitudes (in decibel units) in separate matrices.

The maximum number of trajectories can be specified using setTrajectoryCount().

The algorithm operates by matching the peaks in the current frames to the existing trajectories. During the matching process a maximum frequency change of a peak can be specified using setMaximumFrequencyChange().

The matching process also requires a trajectory to stay unmatched during a given number of frames for the trajectory to disappear and leave a slot for another trajectory to be found. The number fo silent frames can be specified using silentFrameCount().

Author:

Ricard Marxer

See also:

PeakDetection, PeakDetectionComplex, PeakInterpolation, PeakInterpolationComplex, PeakTracking, PeakTrackingComplex

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Constructor & Destructor Documentation

PeakTracking	(	int	trajectoryCount = 20,
		Real	maximumFrequencyChange = 3.0,
		int	silentFrameCount = 3
	)

Constructs a peak tracking object with the given trajectoryCount, maximumFrequencyChange and silentFrameCount settings.

References setMaximumFrequencyChange(), setSilentFrameCount(), and setTrajectoryCount().

~PeakTracking

(

)

Destroys the algorithm and frees its resources.

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Member Function Documentation

void process	(	const MatrixXC &	ffts,
		const MatrixXR &	peakPositions,
		const MatrixXR &	peakMagnitudes,
		MatrixXR *	trajectoryPositions,
		MatrixXR *	trajectoryMagnitudes
	)

Tracks peaks on each of the rows of ffts, peakPositions, peakMagnitudes and puts the resulting trajectory indices and magnitudes in the rows of trajectoryPositions and trajectoryMagnitudes respectively.

Parameters:

	ffts	matrix of Complex values representing the FFT frames.
	peakPositions	matrix of Real values for the peak positions (in fractional index units). The matrix should have the same number of rows as ffts.
	peakMagnitudes	matrix of Real values for the peak magnitudes (in decibel units). The matrix should have the same number of rows as ffts.
	trajectoryPositions	pointer to a matrix of Real values for the trajectory positions (in fractional index units). The matrix should have the same number of rows as ffts and trajectoryCount columns.
	trajectoryMagnitudes	pointer to a matrix of Real values for the trajectory magnitudes (in decibel units). The matrix should have the same number of rows as ffts and trajectoryCount columns.

Note that if the count of trajectories detected is lower than trajectoryCount some values of the resulting arrays will be set to -1.0 in order to indicate that it is not a trajectory.

Note that if the output matrices are not of the required size they will be resized, reallocating a new memory space if necessary.

int trajectoryCount

(

)

const

Returns the maximum number of trajectories to be detected by the algorithm.

By default it is 20.

void setTrajectoryCount	(	int	count,
		bool	callSetup = true
	)

Specifies the maximum trajectory count to be detected by the algorithm. If <= 0, then all possible trajectories are detected.

Parameters:

	count	the maximum number of trajectories to be tracked
	callSetup	a flag specifying whether the setup() method must be called after setting the parameter.

Referenced by PeakTracking().

Real maximumFrequencyChange

(

)

const

Returns the maximum frequency change of a peak for it to be matched to an existing trajectory.

The change is specified in fractional index units.

By default it is 3.0.

void setMaximumFrequencyChange	(	Real	change,
		bool	callSetup = true
	)

Specifies the maximum frequency change of a peak for it to be matched to an existing trajectory.

The change is specified in fractional index units.

Parameters:

	change	the maximum changed allowed between a peak and an existing trajectory
	callSetup	a flag specifying whether the setup() method must be called after setting the parameter.

Referenced by PeakTracking().

int silentFrameCount

(

)

const

Returns the count of frames a trajectory must stay unmatched for it to disappear and leave the slot for another possible trajectory.

By default it is 3.

void setSilentFrameCount	(	int	count,
		bool	callSetup = true
	)

Specifies the count of frames a trajectory must stay unmatched for it to disappear and leave the slot for another possible trajectory.

Parameters:

	count	the number of silent frames
	callSetup	a flag specifying whether the setup() method must be called after setting the parameter.

Referenced by PeakTracking().

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

• PeakTracking.h
• PeakTracking.cpp