Class AverageStat

clover_simulation/src/throttling_camera.cpp:17–99

* Simple statistics-collecting class. */

 * Simple statistics-collecting class.
 */
class AverageStat
{
private:
	/** Currently collected samples. */
	std::deque<double> samples;
	/** Number of samples to store (also, the number of samples considered "adequate") */
	size_t maxSamples;
	/** Currently stored average value */
	double average = 0;
	/** Currently stored standard deviation value */
	double stdev = 0;
	/** Largest standard deviation that is considered adequate */
	double maxStDev;

public:
	AverageStat(size_t numSamples, double validStDev) :
		samples(),
		maxSamples(numSamples),
		maxStDev(validStDev)
	{}

	/**
	 * Add a sample and recalculate average and standard deviation.
	 * 
	 * @param sample New sampled value.
	 * @return New average value.
	 */
	double update(double sample)
	{
		samples.push_back(sample);
		if (samples.size() > maxSamples)
		{
			samples.pop_front();
		}
		average = std::accumulate(samples.begin(), samples.end(), 0.0) / samples.size();
		double stdevSquared = std::accumulate(samples.begin(), samples.end(), 0.0,
			[&](double sum, double xi) {
				return sum + (xi - average) * (xi - average);
			}) / samples.size();
		stdev = std::sqrt(stdevSquared);
		return average;
	}

	/**
	 * Get current average value of all samples.
	 * 
	 * @note This function will return a result even if it is not considered valid.
	 */
	double getAverage() const
	{
		return average;
	}

	/**
	 * Get current standard deviation of all samples.
	 * 
	 * @note This function will return a result even if it is not considered valid.
	 */