/* SPDX-License-Identifier: BSD-2-Clause */ /* * Copyright (C) 2019, Raspberry Pi (Trading) Limited * * histogram.hpp - histogram calculation interface */ #pragma once #include <stdint.h> #include <vector> #include <cassert> // A simple histogram class, for use in particular to find "quantiles" and // averages between "quantiles". namespace RPiController { class Histogram { public: template<typename T> Histogram(T *histogram, int num) { assert(num); cumulative_.reserve(num + 1); cumulative_.push_back(0); for (int i = 0; i < num; i++) cumulative_.push_back(cumulative_.back() + histogram[i]); } uint32_t Bins() const { return cumulative_.size() - 1; } uint64_t Total() const { return cumulative_[cumulative_.size() - 1]; } // Cumulative frequency up to a (fractional) point in a bin. uint64_t CumulativeFreq(double bin) const; // Return the (fractional) bin of the point q (0 <= q <= 1) through the // histogram. Optionally provide limits to help. double Quantile(double q, int first = -1, int last = -1) const; // Return the average histogram bin value between the two quantiles. double InterQuantileMean(double q_lo, double q_hi) const; private: std::vector<uint64_t> cumulative_; }; } // namespace RPiController