annotate src/EM.cpp @ 116:91bb029a847a timing

Reorder the calculations to match the series of vector operations in the most recent bqvec code, just in case it's the order of vector calculations that is saving the time rather than the avoidance of std::vector

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

/*
  Silvet

  A Vamp plugin for note transcription.
  Centre for Digital Music, Queen Mary University of London.
    
  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.
*/

#include "EM.h"

#include "data/include/templates.h"

#include <cstdlib>
#include <cmath>

#include <iostream>

#include <vector>

using std::vector;
using std::cerr;
using std::endl;

static double epsilon = 1e-16;

EM::EM() :
    m_noteCount(SILVET_TEMPLATE_NOTE_COUNT),
    m_shiftCount(SILVET_TEMPLATE_MAX_SHIFT * 2 + 1),
    m_binCount(SILVET_TEMPLATE_HEIGHT),
    m_instrumentCount(SILVET_TEMPLATE_COUNT),
    m_pitchSparsity(1.1),
    m_sourceSparsity(1.3),
    m_lowestPitch(silvet_templates_lowest_note),
    m_highestPitch(silvet_templates_highest_note)
{
    m_pitches = V(m_noteCount);
    for (int n = 0; n < m_noteCount; ++n) {
        m_pitches[n] = drand48();
    }

    m_shifts = Grid(m_shiftCount);
    for (int f = 0; f < m_shiftCount; ++f) {
        m_shifts[f] = V(m_noteCount);
        for (int n = 0; n < m_noteCount; ++n) {
            m_shifts[f][n] = drand48();
        }
    }
    
    m_sources = Grid(m_instrumentCount);
        for (int i = 0; i < m_instrumentCount; ++i) {
        m_sources[i] = V(m_noteCount);
        for (int n = 0; n < m_noteCount; ++n) {
            m_sources[i][n] = (inRange(i, n) ? 1.0 : 0.0);
        }
    }

    m_estimate = V(m_binCount);
    m_q = V(m_binCount);
}

EM::~EM()
{
}

void
EM::rangeFor(int instrument, int &minPitch, int &maxPitch)
{
    minPitch = silvet_templates[instrument].lowest;
    maxPitch = silvet_templates[instrument].highest;
}

bool
EM::inRange(int instrument, int pitch)
{
    int minPitch, maxPitch;
    rangeFor(instrument, minPitch, maxPitch);
    return (pitch >= minPitch && pitch <= maxPitch);
}

void
EM::normaliseColumn(V &column)
{
    double sum = 0.0;
    for (int i = 0; i < (int)column.size(); ++i) {
        sum += column[i];
    }
    for (int i = 0; i < (int)column.size(); ++i) {
        column[i] /= sum;
    }
}

void
EM::normaliseGrid(Grid &grid)
{
    V denominators(grid[0].size());

    for (int i = 0; i < (int)grid.size(); ++i) {
        for (int j = 0; j < (int)grid[i].size(); ++j) {
            denominators[j] += grid[i][j];
        }
    }

    for (int i = 0; i < (int)grid.size(); ++i) {
        for (int j = 0; j < (int)grid[i].size(); ++j) {
            grid[i][j] /= denominators[j];
        }
    }
}

void
EM::iterate(V column)
{
    normaliseColumn(column);
    expectation(column);
    maximisation(column);
}

const double *
EM::templateFor(int instrument, int note, int shift)
{
    return silvet_templates[instrument].data[note] + shift;
}

void
EM::expectation(const V &column)
{
//    cerr << ".";

    for (int i = 0; i < m_binCount; ++i) {
        m_estimate[i] = epsilon;
    }

    for (int i = 0; i < m_instrumentCount; ++i) {
        for (int n = 0; n < m_noteCount; ++n) {
            const double pitch = m_pitches[n];
            const double source = m_sources[i][n];
            for (int f = 0; f < m_shiftCount; ++f) {
                const double *w = templateFor(i, n, f);
                const double shift = m_shifts[f][n];
                const double factor = pitch * source * shift;
                for (int j = 0; j < m_binCount; ++j) {
                    m_estimate[j] += w[j] * factor;
                }
            }
        }
    }

    for (int i = 0; i < m_binCount; ++i) {
        m_q[i] = column[i] / m_estimate[i];
    }
}

void
EM::maximisation(const V &column)
{
    V newPitches(m_noteCount, epsilon);
    Grid newShifts(m_shiftCount, V(m_noteCount, epsilon));
    Grid newSources(m_instrumentCount, V(m_noteCount, epsilon));

    V contributions(m_binCount);

    for (int n = 0; n < m_noteCount; ++n) {

        const double pitch = m_pitches[n];

        for (int f = 0; f < m_shiftCount; ++f) {

            const double shift = m_shifts[f][n];

            for (int i = 0; i < m_instrumentCount; ++i) {

                const double source = m_sources[i][n];
                const double factor = pitch * source * shift;
                const double *w = templateFor(i, n, f);

                for (int j = 0; j < m_binCount; ++j) {
                    contributions[j] = w[j];
                }
                for (int j = 0; j < m_binCount; ++j) {
                    contributions[j] *= m_q.at(j);
                }
                for (int j = 0; j < m_binCount; ++j) {
                    contributions[j] *= factor;
                }

                double total = 0.0;
                for (int j = 0; j < m_binCount; ++j) {
                    total += contributions.at(j);
                }

                if (n >= m_lowestPitch && n <= m_highestPitch) {

                    newPitches[n] += total;
                    
                    if (inRange(i, n)) {
                        newSources[i][n] += total;
                    }
                }

                newShifts[f][n] += total;
            }
        }
    }

    for (int n = 0; n < m_noteCount; ++n) {
        if (m_pitchSparsity != 1.0) {
            newPitches[n] = pow(newPitches[n], m_pitchSparsity);
        }
        if (m_sourceSparsity != 1.0) {
            for (int i = 0; i < m_instrumentCount; ++i) {
                newSources[i][n] = pow(newSources[i][n], m_sourceSparsity);
            }
        }
    }

    normaliseColumn(newPitches);
    normaliseGrid(newShifts);
    normaliseGrid(newSources);

    m_pitches = newPitches;
    m_shifts = newShifts;
    m_sources = newSources;
}