source: src/utils/hist.c @ e2010b3

/*
  Copyright (C) 2003-2009 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 "fvec.h"
#include "utils/scale.h"
#include "mathutils.h" //fvec_min fvec_max
#include "utils/hist.h"

/********
 * Object Structure
 */

struct _aubio_hist_t {
  fvec_t * hist;
  uint_t nelems;
  fvec_t * cent;
  aubio_scale_t *scaler;
};

/**
 * Object creation/deletion calls
 */
aubio_hist_t * new_aubio_hist (smpl_t flow, smpl_t fhig, uint_t nelems){
  aubio_hist_t * s = AUBIO_NEW(aubio_hist_t);
  smpl_t step = (fhig-flow)/(smpl_t)(nelems);
  smpl_t accum = step;
  uint_t i;
  if ((sint_t)nelems <= 0) {
    AUBIO_FREE(s);
    return NULL;
  }
  s->nelems = nelems;
  s->hist = new_fvec(nelems);
  s->cent = new_fvec(nelems);

  /* use scale to map flow/fhig -> 0/nelems */
  s->scaler = new_aubio_scale(flow,fhig,0,nelems);
  /* calculate centers now once */
  s->cent->data[0] = flow + 0.5 * step;
  for (i=1; i < s->nelems; i++, accum+=step )
    s->cent->data[i] = s->cent->data[0] + accum;

  return s;
}

void del_aubio_hist(aubio_hist_t *s) {
  del_fvec(s->hist);
  del_fvec(s->cent);
  del_aubio_scale(s->scaler);
  AUBIO_FREE(s);
}

/***
 * do it
 */
void aubio_hist_do (aubio_hist_t *s, fvec_t *input) {
  uint_t j;
  sint_t tmp = 0;
  aubio_scale_do(s->scaler, input);
  /* reset data */
  fvec_zeros(s->hist);
  /* run accum */
  for (j=0;  j < input->length; j++)
  {
    tmp = (sint_t)FLOOR(input->data[j]);
    if ((tmp >= 0) && (tmp < (sint_t)s->nelems)) {
      s->hist->data[tmp] += 1;
    }
  }
}

void aubio_hist_do_notnull (aubio_hist_t *s, fvec_t *input) {
  uint_t j;
  sint_t tmp = 0;
  aubio_scale_do(s->scaler, input);
  /* reset data */
  fvec_zeros(s->hist);
  /* run accum */
  for (j=0;  j < input->length; j++) {
    if (input->data[j] != 0) {
      tmp = (sint_t)FLOOR(input->data[j]);
      if ((tmp >= 0) && (tmp < (sint_t)s->nelems))
        s->hist->data[tmp] += 1;
    }
  }
}


void aubio_hist_dyn_notnull (aubio_hist_t *s, fvec_t *input) {
  uint_t i;
  sint_t tmp = 0;
  smpl_t ilow = fvec_min(input);
  smpl_t ihig = fvec_max(input);
  smpl_t step = (ihig-ilow)/(smpl_t)(s->nelems);

  /* readapt */
  aubio_scale_set_limits (s->scaler, ilow, ihig, 0, s->nelems);

  /* recalculate centers */
  s->cent->data[0] = ilow + 0.5f * step;
  for (i=1; i < s->nelems; i++)
    s->cent->data[i] = s->cent->data[0] + i * step;

  /* scale */
  aubio_scale_do(s->scaler, input);

  /* reset data */
  fvec_zeros(s->hist);
  /* run accum */
  for (i=0;  i < input->length; i++) {
    if (input->data[i] != 0) {
      tmp = (sint_t)FLOOR(input->data[i]);
      if ((tmp >= 0) && (tmp < (sint_t)s->nelems))
        s->hist->data[tmp] += 1;
    }
  }
}

void aubio_hist_weight (aubio_hist_t *s) {
  uint_t j;
  for (j=0; j < s->nelems; j++) {
    s->hist->data[j] *= s->cent->data[j];
  }
}

smpl_t aubio_hist_mean (const aubio_hist_t *s) {
  uint_t j;
  smpl_t tmp = 0.0;
  for (j=0; j < s->nelems; j++)
    tmp += s->hist->data[j];
  return tmp/(smpl_t)(s->nelems);
}