Fernando Cosentino / MovingAverage

Class for automatic handling of moving averages.

MovingAverage.cpp@0:332104904b69, 2019-03-29 (annotated)

Committer:
fbcosentino
Date:
Fri Mar 29 15:44:58 2019 +0000
Revision:
0:332104904b69
Initial version of a moving average class

Who changed what in which revision?

UserRevisionLine numberNew contents of line
fbcosentino 0:332104904b69 1 #include "MovingAverage.h"
fbcosentino 0:332104904b69 2
fbcosentino 0:332104904b69 3 MovingAverage::MovingAverage(int number_of_samples) {
fbcosentino 0:332104904b69 4 _started = 0;
fbcosentino 0:332104904b69 5 _average = 0.0;
fbcosentino 0:332104904b69 6 _num_samples = number_of_samples;
fbcosentino 0:332104904b69 7 }
fbcosentino 0:332104904b69 8
fbcosentino 0:332104904b69 9 float MovingAverage::filter(float value) {
fbcosentino 0:332104904b69 10 // If this filter has already started, means we have other samples
fbcosentino 0:332104904b69 11 if (_started) {
fbcosentino 0:332104904b69 12 float dropping_value;
fbcosentino 0:332104904b69 13 if (_samples.get(&dropping_value) == 0) { // if no errors
fbcosentino 0:332104904b69 14 // if value == dropping_value, average is kept the same
fbcosentino 0:332104904b69 15 _average = _average + ((value - dropping_value) / _num_samples);
fbcosentino 0:332104904b69 16 _samples.put(value);
fbcosentino 0:332104904b69 17 }
fbcosentino 0:332104904b69 18 }
fbcosentino 0:332104904b69 19 // If we are starting now, this sample is all we have
fbcosentino 0:332104904b69 20 else {
fbcosentino 0:332104904b69 21 // fills the buffer with the initial value
fbcosentino 0:332104904b69 22 for (int i=0; i < _num_samples; i++) _samples.put(value);
fbcosentino 0:332104904b69 23 _started = 1;
fbcosentino 0:332104904b69 24 _average = value; // Average is the initial value.
fbcosentino 0:332104904b69 25 }
fbcosentino 0:332104904b69 26 return _average;
fbcosentino 0:332104904b69 27 }
fbcosentino 0:332104904b69 28
fbcosentino 0:332104904b69 29
fbcosentino 0:332104904b69 30
fbcosentino 0:332104904b69 31 // FIFO HELPER CLASS
fbcosentino 0:332104904b69 32
fbcosentino 0:332104904b69 33 _ma_fifo::_ma_fifo() {
fbcosentino 0:332104904b69 34 head = 0;
fbcosentino 0:332104904b69 35 tail = 0;
fbcosentino 0:332104904b69 36 }
fbcosentino 0:332104904b69 37 int _ma_fifo::available() {
fbcosentino 0:332104904b69 38 return (_MA_FIFO_SIZE + this->head - this->tail) % _MA_FIFO_SIZE;
fbcosentino 0:332104904b69 39 }
fbcosentino 0:332104904b69 40 int _ma_fifo::free() {
fbcosentino 0:332104904b69 41 return (_MA_FIFO_SIZE - 1 - available());
fbcosentino 0:332104904b69 42 }
fbcosentino 0:332104904b69 43 int _ma_fifo::put(float data) {
fbcosentino 0:332104904b69 44 int next;
fbcosentino 0:332104904b69 45 // check if FIFO has room
fbcosentino 0:332104904b69 46 next = (head + 1) % _MA_FIFO_SIZE;
fbcosentino 0:332104904b69 47 if (next == tail) return 1; // fifo full
fbcosentino 0:332104904b69 48
fbcosentino 0:332104904b69 49 buffer[head] = data;
fbcosentino 0:332104904b69 50 head = next;
fbcosentino 0:332104904b69 51 return 0;
fbcosentino 0:332104904b69 52 }
fbcosentino 0:332104904b69 53 int _ma_fifo::get(float * data) {
fbcosentino 0:332104904b69 54 int next;
fbcosentino 0:332104904b69 55 // check if FIFO has data
fbcosentino 0:332104904b69 56 if (head == tail) return 1; // FIFO empty
fbcosentino 0:332104904b69 57
fbcosentino 0:332104904b69 58 next = (tail + 1) % _MA_FIFO_SIZE;
fbcosentino 0:332104904b69 59 *data = buffer[tail];
fbcosentino 0:332104904b69 60 tail = next;
fbcosentino 0:332104904b69 61 return 0;
fbcosentino 0:332104904b69 62 }