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Diffstat (limited to 'FanController/fan_controller/median.c')
| -rw-r--r-- | FanController/fan_controller/median.c | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/FanController/fan_controller/median.c b/FanController/fan_controller/median.c new file mode 100644 index 0000000..03f16d4 --- /dev/null +++ b/FanController/fan_controller/median.c @@ -0,0 +1,131 @@ +/* Autor: Ján Sučan <jan@jansucan.sk> + * + * Zdrojove kody, ich casti a subory z nich vzniknute priamo alebo nepriamo + * (objektove subory, Intel Hex, ...) prosim nepouzivajte komercne, ani ako + * sucast komercnych diel. Vsetky ostatne pripady pouzitia su dovolene. + * + * Please don't use the source codes, their parts and files created from them + * directly or indirectly, (object files, Intel Hex files, ...) for commercial + * purposes, not even as a part of commercial products. All other use cases + * are allowed. + */ + +#include <string.h> + +#include <fan_controller/median.h> +#include <fan_controller/error.h> + +static void median_delete_oldest_sample(median_buffer_t * const buf); + +/** + * @brief Vymazanie najstarsej vzorky z bufferu medianu. + * + * @param buf Ukazovatel na buffer medianu. + */ +void +median_delete_oldest_sample(median_buffer_t * const buf) +{ + // Ziskat index najstarsieho prvku v poli buf->samples + const uint8_t oldest_index = buf->age[0]; + + if (oldest_index >= buf->number_of_elements) { + error(); + } + // Pocet prvkov, ktore sa budu presuvat na prazdne miesto po zmazanom prvku + const uint8_t samples_to_move = buf->number_of_elements - oldest_index - 1; + // Ak je co presuvat, presunie sa + if (samples_to_move > 0) { + memmove(buf->samples + oldest_index, + buf->samples + oldest_index + 1, + samples_to_move * sizeof(buf->samples[0])); + } + + // Zmensi sa pocet ulozenych prvkov + --(buf->number_of_elements); + + // Aktualizovat pozicie presunutych prvkov vo FIFO bufferi + for (uint8_t i = oldest_index; i < (oldest_index + samples_to_move); ++i) { + // Prvky sa posunuli k nizsim indexom + --(buf->age[(buf->samples[i]).age_index]); + } + + // Treba aktualizovat FIFO indexov do buf->samples. Vyhodi sa najstarsi prvok + memmove(buf->age, + buf->age + 1, + buf->number_of_elements * sizeof(buf->samples[0])); + + // Aktualizovat pozicie presunutych prvkov v bufferi vzoriek + for (uint8_t i = 0; i < buf->number_of_elements; ++i) { + // Prvky sa posunuli k nizsim indexom + --(buf->samples[buf->age[i]].age_index); + } +} + +/** + * @brief Inicializacia bufferu medianu. + * + * Buffer medianu sa musi vzdy inicializovat pred prvym pouzitim. + * + * @param buf Ukazovatel na buffer medianu. + * @param capacity Kapacita bufferu, tj. max. pocet vzoriek z ktorych sa bude pocitat median. + */ +void +median_init_buffer(median_buffer_t * const buf, uint8_t capacity) +{ + if ((capacity < MEDIAN_MIN_SAMPLES) ||(capacity > MEDIAN_MAX_SAMPLES)) { + error(); + } + buf->number_of_elements = 0; + buf->capacity = capacity; +} + +/** + * @brief Vlozenie prvku do bufferu pre median. + * + * @param buf Ukazovatel na buffer medianu. + * @param sample Hodnota pre ulozenie do bufferu medianu. + */ +void +median_save_sample(median_buffer_t * const buf, uint16_t sample) +{ + if (buf->number_of_elements >= buf->capacity) { + // Buffer je plny, vymaze sa najtarsi prvok + median_delete_oldest_sample(buf); + } + + // Buffer nie je plny, vzorka sa ulozi na koniec bufferu + buf->samples[buf->number_of_elements].value = sample; + buf->samples[buf->number_of_elements].age_index = buf->number_of_elements; + buf->age[buf->number_of_elements] = buf->number_of_elements; + + // Vzorka sa zaradi na spravne miesto + for (uint8_t j = buf->number_of_elements, i = j - 1; j > 0; --i, --j) { + if (buf->samples[j].value < buf->samples[i].value) { + // Aktualizovat casove znacky + // Vzorka na pozicii i pojde na vyssi index + ++(buf->age[buf->samples[i].age_index]); + // Vzorka na pozicii j pojde na nizsi index + --(buf->age[buf->samples[j].age_index]); + // Vymenit vzorky + median_sample_t t; + t = buf->samples[j]; + buf->samples[j] = buf->samples[i]; + buf->samples[i] = t; + } + } + + // Aktualizovat pocet ulozenych prvkov + ++(buf->number_of_elements); +} + +/** + * @brief Ziskanie medianu z bufferu. + * + * @param buf Ukazovatel na buffer medianu. + * @return Median z doteraz ulozenych hodnot. + */ +uint16_t +median_get(const median_buffer_t * const buf) +{ + return (buf->samples[buf->number_of_elements / 2]).value; +}
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