annotate maths/MathUtilities.h @ 321:f1e6be2de9a5

A threshold (delta) is added in the peak picking parameters structure (PPickParams). It is used as an offset when computing the smoothed detection function. A constructor for the structure PPickParams is also added to set the parameters to 0 when a structure instance is created. Hence programmes using the peak picking parameter structure and which do not set the delta parameter (e.g. QM Vamp note onset detector) won't be affected by the modifications.

Functions modified:
- dsp/onsets/PeakPicking.cpp
- dsp/onsets/PeakPicking.h
- dsp/signalconditioning/DFProcess.cpp
- dsp/signalconditioning/DFProcess.h

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    QM DSP Library

    Centre for Digital Music, Queen Mary, University of London.
    This file 2005-2006 Christian Landone.

    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
    published by the Free Software Foundation; either version 2 of the
    License, or (at your option) any later version.  See the file
    COPYING included with this distribution for more information.
*/

#ifndef MATHUTILITIES_H
#define MATHUTILITIES_H

#include <vector>

#include "nan-inf.h"

class MathUtilities  
{
public:	
    static double round( double x );

    static void	  getFrameMinMax( const double* data, unsigned int len,  double* min, double* max );

    static double mean( const double* src, unsigned int len );
    static double mean( const std::vector<double> &data,
                        unsigned int start, unsigned int count );
    static double sum( const double* src, unsigned int len );
    static double median( const double* src, unsigned int len );

    static double princarg( double ang );
    static double mod( double x, double y);

    static void	  getAlphaNorm(const double *data, unsigned int len, unsigned int alpha, double* ANorm);
    static double getAlphaNorm(const std::vector <double> &data, unsigned int alpha );

    static void   circShift( double* data, int length, int shift);

    static int	  getMax( double* data, unsigned int length, double* max = 0 );
    static int	  getMax( const std::vector<double> &data, double* max = 0 );
    static int    compareInt(const void * a, const void * b);

    enum NormaliseType {
        NormaliseNone,
        NormaliseUnitSum,
        NormaliseUnitMax
    };

    static void   normalise(double *data, int length,
                            NormaliseType n = NormaliseUnitMax);

    static void   normalise(std::vector<double> &data,
                            NormaliseType n = NormaliseUnitMax);

    // moving mean threshholding:
    static void adaptiveThreshold(std::vector<double> &data);

    static bool isPowerOfTwo(int x);
    static int nextPowerOfTwo(int x); // e.g. 1300 -> 2048, 2048 -> 2048
    static int previousPowerOfTwo(int x); // e.g. 1300 -> 1024, 2048 -> 2048
    static int nearestPowerOfTwo(int x); // e.g. 1300 -> 1024, 1700 -> 2048
};

#endif