83 lines
2.0 KiB
C
83 lines
2.0 KiB
C
/**
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* @file mave.c
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* @note Copyright (C) 2011 Richard Cochran <richardcochran@gmail.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include <stdlib.h>
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#include <string.h>
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#include "mave.h"
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#include "filter_private.h"
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struct mave {
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struct filter filter;
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int cnt;
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int len;
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int index;
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tmv_t sum;
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tmv_t *val;
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};
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static void mave_destroy(struct filter *filter)
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{
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struct mave *m = container_of(filter, struct mave, filter);
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free(m->val);
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free(m);
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}
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static tmv_t mave_accumulate(struct filter *filter, tmv_t val)
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{
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struct mave *m = container_of(filter, struct mave, filter);
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m->sum = tmv_sub(m->sum, m->val[m->index]);
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m->val[m->index] = val;
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m->index = (1 + m->index) % m->len;
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m->sum = tmv_add(m->sum, val);
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if (m->cnt < m->len) {
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m->cnt++;
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}
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return tmv_div(m->sum, m->cnt);
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}
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static void mave_reset(struct filter *filter)
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{
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struct mave *m = container_of(filter, struct mave, filter);
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m->cnt = 0;
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m->index = 0;
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m->sum = tmv_zero();
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memset(m->val, 0, m->len * sizeof(*m->val));
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}
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struct filter *mave_create(int length)
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{
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struct mave *m;
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m = calloc(1, sizeof(*m));
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if (!m) {
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return NULL;
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}
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m->filter.destroy = mave_destroy;
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m->filter.sample = mave_accumulate;
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m->filter.reset = mave_reset;
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m->val = calloc(1, length * sizeof(*m->val));
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if (!m->val) {
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free(m);
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return NULL;
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}
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m->len = length;
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return &m->filter;
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}
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