cannam@0: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
cannam@0: 
cannam@0: /*
cannam@0:     QM DSP Library
cannam@0: 
cannam@0:     Centre for Digital Music, Queen Mary, University of London.
cannam@0:     This file copyright 2005-2006 Christian Landone.
cannam@0:     All rights reserved.
cannam@0: */
cannam@0: 
cannam@0: #include "MathUtilities.h"
cannam@0: 
cannam@0: #include <iostream>
cannam@0: #include <cmath>
cannam@0: 
cannam@0: 
cannam@0: double MathUtilities::mod(double x, double y)
cannam@0: {
cannam@0:     double a = floor( x / y );
cannam@0: 
cannam@0:     double b = x - ( y * a );
cannam@0:     return b;
cannam@0: }
cannam@0: 
cannam@0: double MathUtilities::princarg(double ang)
cannam@0: {
cannam@0:     double ValOut;
cannam@0: 
cannam@0:     ValOut = mod( ang + M_PI, -2 * M_PI ) + M_PI;
cannam@0: 
cannam@0:     return ValOut;
cannam@0: }
cannam@0: 
cannam@0: void MathUtilities::getAlphaNorm(const double *data, unsigned int len, unsigned int alpha, double* ANorm)
cannam@0: {
cannam@0:     unsigned int i;
cannam@0:     double temp = 0.0;
cannam@0:     double a=0.0;
cannam@0: 	
cannam@0:     for( i = 0; i < len; i++)
cannam@0:     {
cannam@0: 	temp = data[ i ];
cannam@0: 		
cannam@0: 	a  += ::pow( fabs(temp), alpha );
cannam@0:     }
cannam@0:     a /= ( double )len;
cannam@0:     a = ::pow( a, ( 1.0 / (double) alpha ) );
cannam@0: 
cannam@0:     *ANorm = a;
cannam@0: }
cannam@0: 
cannam@0: double MathUtilities::getAlphaNorm( const std::vector <double> &data, unsigned int alpha )
cannam@0: {
cannam@0:     unsigned int i;
cannam@0:     unsigned int len = data.size();
cannam@0:     double temp = 0.0;
cannam@0:     double a=0.0;
cannam@0: 	
cannam@0:     for( i = 0; i < len; i++)
cannam@0:     {
cannam@0: 	temp = data[ i ];
cannam@0: 		
cannam@0: 	a  += ::pow( fabs(temp), alpha );
cannam@0:     }
cannam@0:     a /= ( double )len;
cannam@0:     a = ::pow( a, ( 1.0 / (double) alpha ) );
cannam@0: 
cannam@0:     return a;
cannam@0: }
cannam@0: 
cannam@0: double MathUtilities::round(double x)
cannam@0: {
cannam@0:     double val = (double)floor(x + 0.5);
cannam@0:   
cannam@0:     return val;
cannam@0: }
cannam@0: 
cannam@0: double MathUtilities::median(const double *src, unsigned int len)
cannam@0: {
cannam@0:     unsigned int i, j;
cannam@0:     double tmp = 0.0;
cannam@0:     double tempMedian;
cannam@0:     double medianVal;
cannam@0:  
cannam@0:     double* scratch = new double[ len ];//Vector < double > sortedX = Vector < double > ( size );
cannam@0: 
cannam@0:     for ( i = 0; i < len; i++ )
cannam@0:     {
cannam@0: 	scratch[i] = src[i];
cannam@0:     }
cannam@0: 
cannam@0:     for ( i = 0; i < len - 1; i++ )
cannam@0:     {
cannam@0: 	for ( j = 0; j < len - 1 - i; j++ )
cannam@0: 	{
cannam@0: 	    if ( scratch[j + 1] < scratch[j] )
cannam@0: 	    {
cannam@0: 		// compare the two neighbors
cannam@0: 		tmp = scratch[j]; // swap a[j] and a[j+1]
cannam@0: 		scratch[j] = scratch[j + 1];
cannam@0: 		scratch[j + 1] = tmp;
cannam@0: 	    }
cannam@0: 	}
cannam@0:     }
cannam@0:     int middle;
cannam@0:     if ( len % 2 == 0 )
cannam@0:     {
cannam@0: 	middle = len / 2;
cannam@0: 	tempMedian = ( scratch[middle] + scratch[middle - 1] ) / 2;
cannam@0:     }
cannam@0:     else
cannam@0:     {
cannam@0: 	middle = ( int )floor( len / 2.0 );
cannam@0: 	tempMedian = scratch[middle];
cannam@0:     }
cannam@0: 
cannam@0:     medianVal = tempMedian;
cannam@0: 
cannam@0:     delete [] scratch;
cannam@0:     return medianVal;
cannam@0: }
cannam@0: 
cannam@0: double MathUtilities::sum(const double *src, unsigned int len)
cannam@0: {
cannam@0:     unsigned int i ;
cannam@0:     double retVal =0.0;
cannam@0: 
cannam@0:     for(  i = 0; i < len; i++)
cannam@0:     {
cannam@0: 	retVal += src[ i ];
cannam@0:     }
cannam@0: 
cannam@0:     return retVal;
cannam@0: }
cannam@0: 
cannam@0: double MathUtilities::mean(const double *src, unsigned int len)
cannam@0: {
cannam@0:     double retVal =0.0;
cannam@0: 
cannam@0:     double s = sum( src, len );
cannam@0: 	
cannam@0:     retVal =  s  / (double)len;
cannam@0: 
cannam@0:     return retVal;
cannam@0: }
cannam@0: 
cannam@0: void MathUtilities::getFrameMinMax(const double *data, unsigned int len, double *min, double *max)
cannam@0: {
cannam@0:     unsigned int i;
cannam@0:     double temp = 0.0;
cannam@0:     double a=0.0;
cannam@0: 	
cannam@0:     *min = data[0];
cannam@0:     *max = data[0];
cannam@0: 
cannam@0:     for( i = 0; i < len; i++)
cannam@0:     {
cannam@0: 	temp = data[ i ];
cannam@0: 
cannam@0: 	if( temp < *min )
cannam@0: 	{
cannam@0: 	    *min =  temp ;
cannam@0: 	}
cannam@0: 	if( temp > *max )
cannam@0: 	{
cannam@0: 	    *max =  temp ;
cannam@0: 	}
cannam@0: 		
cannam@0:     }
cannam@0: }