# PeakDetection Class Reference

Algorithm to find peaks in a vector of Real values. More...

`#include <PeakDetection.h>`

List of all members.

## Public Types

enum  SortMethod { NONE = 0, BYMAGNITUDE = 1, BYPOSITION = 2 }
Specifies the way to sort the peak candidates before returning them. More...

## Public Member Functions

PeakDetection (int peakCount=1024/3, SortMethod sort=BYMAGNITUDE, int minimumPeakWidth=3, int candidateCount=-1, Real minimumPeakContrast=0)
~PeakDetection ()
void process (const MatrixXR &frames, MatrixXR *peakPositions, MatrixXR *peakMagnitudes)
int peakCount () const
void setPeakCount (int count, bool callSetup=true)
int minimumPeakWidth () const
void setMinimumPeakWidth (int width, bool callSetup=true)
int candidateCount () const
void setCandidateCount (int count, bool callSetup=true)
Real minimumPeakContrast () const
void setMinimumPeakContrast (Real contrast, bool callSetup=true)
SortMethod sortMethod () const
void setSortMethod (SortMethod method, bool callSetup=true)

## Detailed Description

Algorithm to find peaks in a vector of Real values.

This class represents an object to find peaks in a vector of Real values. The algorithm finds a maximum number of peaks and returns the indices of the peaks and the values of the peaks in separate matrices.

The maximum number of peaks can be specified using setPeakCount().

The resulting peak arrays may be sorted by position or by magnitude. This can be specified using setSortMethod().

When sorting by position it may be interesting to specify a number of candidates, in order to perform a preselection of the highest valued peaks before sorting. This can be specified using setCandidateCount().

The implementation consists in running a sliding windows along the vector in search of indices which whose value is the maximum of the window. The size of the window defines the minimum width of the peak.

See also:
PeakDetection, PeakDetectionComplex, PeakInterpolation, PeakInterpolationComplex, PeakTracking, PeakTrackingComplex

## Member Enumeration Documentation

 enum SortMethod

Specifies the way to sort the peak candidates before returning them.

See also:
sortMethod
Enumerator:
 NONE No sorting is performed BYMAGNITUDE Sorts the peak candidates by decreasing order of magnitude BYPOSITION Sorts the peak candidates by increasing order of position

## Constructor & Destructor Documentation

 PeakDetection ( int peakCount = `1024 / 3`, SortMethod sort = `BYMAGNITUDE`, int minimumPeakWidth = `3`, int candidateCount = `-1`, Real minimumPeakContrast = `0` )

Constructs a peak detection object with the given peakCount, sort method, minimumPeakWidth, candidateCount and minimumPeakContrast parameters given.

 ~PeakDetection ( )

Destroys the algorithm and frees its resources.

## Member Function Documentation

 void process ( const MatrixXR & frames, MatrixXR * peakPositions, MatrixXR * peakMagnitudes )

Detects peaks on each of the rows of frames and puts the resulting peak indices and magnitudes in the rows of peakPositions and peakMagnitudes respectively.

Parameters:
 frames matrix of Real values. peakPositions pointer to a matrix of Real values (but always Integers) for the peak indices. The matrix should have the same number of rows as frames and peakCount columns. peakMagnitudes pointer to a matrix of Real values for the peak magnitudes. The matrix should have the same number of rows as frames and peakCount columns.
Note that if the count of peaks detect is lower than peakCount some values of the resulting arrays will be set to -1.0 in order to indicate that it is not a peak.

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

References BYMAGNITUDE, BYPOSITION, candidateCount(), NONE, and peakCount().

Referenced by PitchACF::process().

 int peakCount ( ) const

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

By default it is 1024 / 3.

Referenced by process().

 void setPeakCount ( int count, bool callSetup = `true` )

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

Referenced by PeakDetection().

 int minimumPeakWidth ( ) const

Returns the minimum width of a peak for it to be detected.

By default it is 3.

 void setMinimumPeakWidth ( int width, bool callSetup = `true` )

Specifies the minimum width of a peak for it to be detected.

Referenced by PeakDetection().

 int candidateCount ( ) const

Returns the number of highest value candidates to be considered before sorting.

Note that if the value is <= 0, then no preselection is performed and all detected peaks are considered as candidates.

By default it is -1.

Referenced by process().

 void setCandidateCount ( int count, bool callSetup = `true` )

Specifies the number of highest value candidates to be considered before sorting.

Note that if the value is <= 0, then no preselection is performed and all detected peaks are considered as candidates.

Referenced by PeakDetection().

 Real minimumPeakContrast ( ) const

Returns the minimum contrast of a peak for it to be detected.

The contrast is considered of a peak is the maximum value minus the minimum value of all the points in the peak detection running window.

By default it is 0.0.

 void setMinimumPeakContrast ( Real contrast, bool callSetup = `true` )

Specifies the minimum contrast of a peak for it to be detected.

The contrast is considered of a peak is the maximum value minus the minimum value of all the points in the peak detection running window.

Referenced by PeakDetection().

 PeakDetection::SortMethod sortMethod ( ) const

Returns the method for sorting the peaks.

By default it is BYMAGNITUDE.

 void setSortMethod ( SortMethod method, bool callSetup = `true` )

Specifies the method for sorting the peaks.

Referenced by PeakDetection().

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

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