Implement median filter (#697)

Add median filter to sensors component
This commit is contained in:
Jasper van der Neut - Stulen 2019-08-27 19:39:04 +02:00 committed by Brandon Davidson
parent c5db457700
commit 0fc267dfc7
4 changed files with 86 additions and 0 deletions

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@ -61,6 +61,7 @@ SensorPublishAction = sensor_ns.class_('SensorPublishAction', automation.Action)
# Filters
Filter = sensor_ns.class_('Filter')
MedianFilter = sensor_ns.class_('MedianFilter', Filter)
SlidingWindowMovingAverageFilter = sensor_ns.class_('SlidingWindowMovingAverageFilter', Filter)
ExponentialMovingAverageFilter = sensor_ns.class_('ExponentialMovingAverageFilter', Filter)
LambdaFilter = sensor_ns.class_('LambdaFilter', Filter)
@ -127,6 +128,19 @@ def filter_out_filter_to_code(config, filter_id):
yield cg.new_Pvariable(filter_id, config)
MEDIAN_SCHEMA = cv.All(cv.Schema({
cv.Optional(CONF_WINDOW_SIZE, default=5): cv.positive_not_null_int,
cv.Optional(CONF_SEND_EVERY, default=5): cv.positive_not_null_int,
cv.Optional(CONF_SEND_FIRST_AT, default=1): cv.positive_not_null_int,
}), validate_send_first_at)
@FILTER_REGISTRY.register('median', MedianFilter, MEDIAN_SCHEMA)
def median_filter_to_code(config, filter_id):
yield cg.new_Pvariable(filter_id, config[CONF_WINDOW_SIZE], config[CONF_SEND_EVERY],
config[CONF_SEND_FIRST_AT])
SLIDING_AVERAGE_SCHEMA = cv.All(cv.Schema({
cv.Optional(CONF_WINDOW_SIZE, default=15): cv.positive_not_null_int,
cv.Optional(CONF_SEND_EVERY, default=15): cv.positive_not_null_int,

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@ -39,6 +39,44 @@ uint32_t Filter::calculate_remaining_interval(uint32_t input) {
}
}
// MedianFilter
MedianFilter::MedianFilter(size_t window_size, size_t send_every, size_t send_first_at)
: send_every_(send_every), send_at_(send_every - send_first_at), window_size_(window_size) {}
void MedianFilter::set_send_every(size_t send_every) { this->send_every_ = send_every; }
void MedianFilter::set_window_size(size_t window_size) { this->window_size_ = window_size; }
optional<float> MedianFilter::new_value(float value) {
if (!isnan(value)) {
while (this->queue_.size() >= this->window_size_) {
this->queue_.pop_front();
}
this->queue_.push_back(value);
ESP_LOGVV(TAG, "MedianFilter(%p)::new_value(%f)", this, value);
}
if (++this->send_at_ >= this->send_every_) {
this->send_at_ = 0;
float median = 0.0f;
if (!this->queue_.empty()) {
std::deque<float> median_queue = this->queue_;
sort(median_queue.begin(), median_queue.end());
size_t queue_size = median_queue.size();
if (queue_size % 2) {
median = median_queue[queue_size / 2];
} else {
median = (median_queue[queue_size / 2] + median_queue[(queue_size / 2) - 1]) / 2.0f;
}
}
ESP_LOGVV(TAG, "MedianFilter(%p)::new_value(%f) SENDING", this, median);
return median;
}
return {};
}
uint32_t MedianFilter::expected_interval(uint32_t input) { return input * this->send_every_; }
// SlidingWindowMovingAverageFilter
SlidingWindowMovingAverageFilter::SlidingWindowMovingAverageFilter(size_t window_size, size_t send_every,
size_t send_first_at)

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@ -46,6 +46,36 @@ class Filter {
Sensor *parent_{nullptr};
};
/** Simple median filter.
*
* Takes the median of the last <send_every> values and pushes it out every <send_every>.
*/
class MedianFilter : public Filter {
public:
/** Construct a MedianFilter.
*
* @param window_size The number of values that should be used in median calculation.
* @param send_every After how many sensor values should a new one be pushed out.
* @param send_first_at After how many values to forward the very first value. Defaults to the first value
* on startup being published on the first *raw* value, so with no filter applied. Must be less than or equal to
* send_every.
*/
explicit MedianFilter(size_t window_size, size_t send_every, size_t send_first_at);
optional<float> new_value(float value) override;
void set_send_every(size_t send_every);
void set_window_size(size_t window_size);
uint32_t expected_interval(uint32_t input) override;
protected:
std::deque<float> queue_;
size_t send_every_;
size_t send_at_;
size_t window_size_;
};
/** Simple sliding window moving average filter.
*
* Essentially just takes takes the average of the last window_size values and pushes them out

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@ -191,6 +191,10 @@ sensor:
- 100.0 -> 102.5
- filter_out: 42.0
- filter_out: nan
- median:
window_size: 5
send_every: 5
send_first_at: 3
- sliding_window_moving_average:
window_size: 15
send_every: 15