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/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
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Centre for Digital Music, Queen Mary, University of London.
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This file 2005-2006 Christian Landone.
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This program is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version. See the file
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COPYING included with this distribution for more information.
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#include "MathUtilities.h"
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double MathUtilities::mod(double x, double y)
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double a = floor( x / y );
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double b = x - ( y * a );
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double MathUtilities::princarg(double ang)
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ValOut = mod( ang + M_PI, -2 * M_PI ) + M_PI;
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void MathUtilities::getAlphaNorm(const double *data, unsigned int len, unsigned int alpha, double* ANorm)
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for( i = 0; i < len; i++)
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a += ::pow( fabs(temp), double(alpha) );
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a = ::pow( a, ( 1.0 / (double) alpha ) );
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double MathUtilities::getAlphaNorm( const std::vector <double> &data, unsigned int alpha )
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unsigned int len = data.size();
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for( i = 0; i < len; i++)
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a += ::pow( fabs(temp), double(alpha) );
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a = ::pow( a, ( 1.0 / (double) alpha ) );
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double MathUtilities::round(double x)
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double val = (double)floor(x + 0.5);
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double MathUtilities::median(const double *src, unsigned int len)
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double* scratch = new double[ len ];//Vector < double > sortedX = Vector < double > ( size );
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for ( i = 0; i < len; i++ )
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for ( i = 0; i < len - 1; i++ )
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for ( j = 0; j < len - 1 - i; j++ )
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if ( scratch[j + 1] < scratch[j] )
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// compare the two neighbors
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tmp = scratch[j]; // swap a[j] and a[j+1]
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scratch[j] = scratch[j + 1];
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scratch[j + 1] = tmp;
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tempMedian = ( scratch[middle] + scratch[middle - 1] ) / 2;
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middle = ( int )floor( len / 2.0 );
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tempMedian = scratch[middle];
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medianVal = tempMedian;
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double MathUtilities::sum(const double *src, unsigned int len)
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for( i = 0; i < len; i++)
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double MathUtilities::mean(const double *src, unsigned int len)
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double s = sum( src, len );
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retVal = s / (double)len;
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double MathUtilities::mean(const std::vector<double> &src,
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for (unsigned int i = 0; i < count; ++i)
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sum += src[start + i];
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void MathUtilities::getFrameMinMax(const double *data, unsigned int len, double *min, double *max)
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for( i = 0; i < len; i++)
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int MathUtilities::getMax( double* pData, unsigned int Length, double* pMax )
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unsigned int index = 0;
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double max = pData[0];
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for( i = 0; i < Length; i++)
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if (pMax) *pMax = max;
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int MathUtilities::getMax( const std::vector<double> & data, double* pMax )
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unsigned int index = 0;
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double max = data[0];
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for( i = 0; i < data.size(); i++)
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if (pMax) *pMax = max;
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void MathUtilities::circShift( double* pData, int length, int shift)
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shift = shift % length;
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for( i = 0; i < shift; i++)
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temp=*(pData + length - 1);
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for( n = length-2; n >= 0; n--)
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*(pData+n+1)=*(pData+n);
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int MathUtilities::compareInt (const void * a, const void * b)
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return ( *(const int*)a - *(const int*)b );
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void MathUtilities::normalise(double *data, int length, NormaliseType type)
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case NormaliseNone: return;
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case NormaliseUnitSum:
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for (int i = 0; i < length; ++i) {
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for (int i = 0; i < length; ++i) {
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case NormaliseUnitMax:
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for (int i = 0; i < length; ++i) {
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if (fabs(data[i]) > max) {
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for (int i = 0; i < length; ++i) {
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void MathUtilities::normalise(std::vector<double> &data, NormaliseType type)
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case NormaliseNone: return;
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case NormaliseUnitSum:
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for (unsigned int i = 0; i < data.size(); ++i) sum += data[i];
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for (unsigned int i = 0; i < data.size(); ++i) data[i] /= sum;
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case NormaliseUnitMax:
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for (unsigned int i = 0; i < data.size(); ++i) {
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if (fabs(data[i]) > max) max = fabs(data[i]);
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for (unsigned int i = 0; i < data.size(); ++i) data[i] /= max;
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void MathUtilities::adaptiveThreshold(std::vector<double> &data)
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int sz = int(data.size());
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std::vector<double> smoothed(sz);
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for (int i = 0; i < sz; ++i) {
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int first = std::max(0, i - p_pre);
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int last = std::min(sz - 1, i + p_post);
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smoothed[i] = mean(data, first, last - first + 1);
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for (int i = 0; i < sz; i++) {
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data[i] -= smoothed[i];
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if (data[i] < 0.0) data[i] = 0.0;
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MathUtilities::isPowerOfTwo(int x)
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if (x < 2) return false;
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if (x & (x-1)) return false;
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MathUtilities::nextPowerOfTwo(int x)
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if (isPowerOfTwo(x)) return x;
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while (x) { x >>= 1; n <<= 1; }
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MathUtilities::previousPowerOfTwo(int x)
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if (isPowerOfTwo(x)) return x;
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while (x) { x >>= 1; n <<= 1; }
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MathUtilities::nearestPowerOfTwo(int x)
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if (isPowerOfTwo(x)) return x;
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int n0 = previousPowerOfTwo(x), n1 = nearestPowerOfTwo(x);
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if (x - n0 < n1 - x) return n0;