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Diffstat (limited to 'src/spectral/statistics.c')
| -rw-r--r-- | src/spectral/statistics.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/src/spectral/statistics.c b/src/spectral/statistics.c new file mode 100644 index 0000000..4fd66c0 --- /dev/null +++ b/src/spectral/statistics.c @@ -0,0 +1,204 @@ +/* + 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/specdesc.h" + +void aubio_specdesc_centroid (aubio_specdesc_t * o, const cvec_t * spec, + fvec_t * desc); +void aubio_specdesc_spread (aubio_specdesc_t * o, const cvec_t * spec, + fvec_t * desc); +void aubio_specdesc_skewness (aubio_specdesc_t * o, const cvec_t * spec, + fvec_t * desc); +void aubio_specdesc_kurtosis (aubio_specdesc_t * o, const cvec_t * spec, + fvec_t * desc); +void aubio_specdesc_slope (aubio_specdesc_t * o, const cvec_t * spec, + fvec_t * desc); +void aubio_specdesc_decrease (aubio_specdesc_t * o, const cvec_t * spec, + fvec_t * desc); +void aubio_specdesc_rolloff (aubio_specdesc_t * o, const cvec_t * spec, + fvec_t * desc); + + +smpl_t cvec_sum (const cvec_t * s); +smpl_t cvec_mean (const cvec_t * s); +smpl_t cvec_centroid (const cvec_t * s); +smpl_t cvec_moment (const cvec_t * s, uint_t moment); + +smpl_t +cvec_sum (const cvec_t * s) +{ + uint_t j; + smpl_t tmp = 0.0; + for (j = 0; j < s->length; j++) { + tmp += s->norm[j]; + } + return tmp; +} + +smpl_t +cvec_mean (const cvec_t * s) +{ + return cvec_sum (s) / (smpl_t) (s->length); +} + +smpl_t +cvec_centroid (const cvec_t * spec) +{ + smpl_t sum = 0., sc = 0.; + uint_t j; + sum = cvec_sum (spec); + if (sum == 0.) { + return 0.; + } else { + for (j = 0; j < spec->length; j++) { + sc += (smpl_t) j *spec->norm[j]; + } + return sc / sum; + } +} + +smpl_t +cvec_moment (const cvec_t * spec, uint_t order) +{ + smpl_t sum = 0., centroid = 0., sc = 0.; + uint_t j; + sum = cvec_sum (spec); + if (sum == 0.) { + return 0.; + } else { + centroid = cvec_centroid (spec); + for (j = 0; j < spec->length; j++) { + sc += (smpl_t) POW(j - centroid, order) * spec->norm[j]; + } + return sc / sum; + } +} + +void +aubio_specdesc_centroid (aubio_specdesc_t * o UNUSED, const cvec_t * spec, + fvec_t * desc) +{ + desc->data[0] = cvec_centroid (spec); +} + +void +aubio_specdesc_spread (aubio_specdesc_t * o UNUSED, const cvec_t * spec, + fvec_t * desc) +{ + desc->data[0] = cvec_moment (spec, 2); +} + +void +aubio_specdesc_skewness (aubio_specdesc_t * o UNUSED, const cvec_t * spec, + fvec_t * desc) +{ + smpl_t spread; + spread = cvec_moment (spec, 2); + if (spread == 0) { + desc->data[0] = 0.; + } else { + desc->data[0] = cvec_moment (spec, 3); + desc->data[0] /= POW ( SQRT (spread), 3); + } +} + +void +aubio_specdesc_kurtosis (aubio_specdesc_t * o UNUSED, const cvec_t * spec, + fvec_t * desc) +{ + smpl_t spread; + spread = cvec_moment (spec, 2); + if (spread == 0) { + desc->data[0] = 0.; + } else { + desc->data[0] = cvec_moment (spec, 4); + desc->data[0] /= SQR (spread); + } +} + +void +aubio_specdesc_slope (aubio_specdesc_t * o UNUSED, const cvec_t * spec, + fvec_t * desc) +{ + uint_t j; + smpl_t norm = 0, sum = 0.; + // compute N * sum(j**2) - sum(j)**2 + for (j = 0; j < spec->length; j++) { + norm += j*j; + } + norm *= spec->length; + // sum_0^N(j) = length * (length + 1) / 2 + norm -= SQR( (spec->length) * (spec->length - 1.) / 2. ); + sum = cvec_sum (spec); + desc->data[0] = 0.; + if (sum == 0.) { + return; + } else { + for (j = 0; j < spec->length; j++) { + desc->data[0] += j * spec->norm[j]; + } + desc->data[0] *= spec->length; + desc->data[0] -= sum * spec->length * (spec->length - 1) / 2.; + desc->data[0] /= norm; + desc->data[0] /= sum; + } +} + +void +aubio_specdesc_decrease (aubio_specdesc_t *o UNUSED, const cvec_t * spec, + fvec_t * desc) +{ + uint_t j; smpl_t sum; + sum = cvec_sum (spec); + desc->data[0] = 0; + if (sum == 0.) { + return; + } else { + sum -= spec->norm[0]; + for (j = 1; j < spec->length; j++) { + desc->data[0] += (spec->norm[j] - spec->norm[0]) / j; + } + desc->data[0] /= sum; + } +} + +void +aubio_specdesc_rolloff (aubio_specdesc_t *o UNUSED, const cvec_t * spec, + fvec_t *desc) +{ + uint_t j; smpl_t cumsum, rollsum; + cumsum = 0.; rollsum = 0.; + for (j = 0; j < spec->length; j++) { + cumsum += SQR (spec->norm[j]); + } + if (cumsum == 0) { + desc->data[0] = 0.; + } else { + cumsum *= 0.95; + j = 0; + while (rollsum < cumsum) { + rollsum += SQR (spec->norm[j]); + j++; + } + desc->data[0] = j; + } +} |