shithub: aubio

ref: 20d8266e4b5ff10f33b90e485e1f2d0ed48b8c5a
dir: /src/spectral/spectral_centroid.c/

/*
  Copyright (C) 2007-2009 Paul Brossier <piem@aubio.org>

  This file is part of aubio.

  aubio 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 3 of the License, or
  (at your option) any later version.

  aubio is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with aubio.  If not, see <http://www.gnu.org/licenses/>.

*/

#include "aubio_priv.h"
#include "cvec.h"
#include "spectral/spectral_centroid.h"

smpl_t aubio_spectral_centroid(cvec_t * spectrum, smpl_t samplerate) {
  uint_t i=0, j;
  smpl_t sum = 0., sc = 0.;
  for ( j = 0; j < spectrum->length; j++ ) {
    sum += spectrum->norm[i][j];
  }
  if (sum == 0.) return 0.;
  for ( j = 0; j < spectrum->length; j++ ) {
    sc += (smpl_t)j * spectrum->norm[i][j];
  }
  return sc / sum * samplerate / (smpl_t)(spectrum->length);
}