42 lines
989 B
C
42 lines
989 B
C
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#pragma once
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#include <cstddef>
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#include <array>
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namespace Pinetime {
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namespace Utility {
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// based on: https://github.com/SHristov92/LinearApproximation/blob/main/Linear.h
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template <typename Key, typename Value, std::size_t Size> class LinearApproximation {
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using Point = struct {
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Key key;
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Value value;
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};
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public:
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LinearApproximation(const std::array<Point, Size>&& sorted_points) : points {sorted_points} {
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}
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Value GetValue(Key key) const {
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if (key <= points[0].key) {
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return points[0].value;
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}
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for (std::size_t i = 1; i < Size; i++) {
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const auto& p = points[i];
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const auto& p_prev = points[i - 1];
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if (key < p.key) {
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return p_prev.value + (key - p_prev.key) * (p.value - p_prev.value) / (p.key - p_prev.key);
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}
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}
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return points[Size - 1].value;
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}
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private:
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std::array<Point, Size> points;
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};
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}
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}
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