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Diffstat (limited to 'src/ipa/raspberrypi/controller/pwl.cpp')
-rw-r--r-- | src/ipa/raspberrypi/controller/pwl.cpp | 246 |
1 files changed, 0 insertions, 246 deletions
diff --git a/src/ipa/raspberrypi/controller/pwl.cpp b/src/ipa/raspberrypi/controller/pwl.cpp deleted file mode 100644 index 130c820b..00000000 --- a/src/ipa/raspberrypi/controller/pwl.cpp +++ /dev/null @@ -1,246 +0,0 @@ -/* SPDX-License-Identifier: BSD-2-Clause */ -/* - * Copyright (C) 2019, Raspberry Pi (Trading) Limited - * - * pwl.cpp - piecewise linear functions - */ - -#include <cassert> -#include <stdexcept> - -#include "pwl.hpp" - -using namespace RPiController; - -void Pwl::Read(boost::property_tree::ptree const ¶ms) -{ - for (auto it = params.begin(); it != params.end(); it++) { - double x = it->second.get_value<double>(); - assert(it == params.begin() || x > points_.back().x); - it++; - double y = it->second.get_value<double>(); - points_.push_back(Point(x, y)); - } - assert(points_.size() >= 2); -} - -void Pwl::Append(double x, double y, const double eps) -{ - if (points_.empty() || points_.back().x + eps < x) - points_.push_back(Point(x, y)); -} - -void Pwl::Prepend(double x, double y, const double eps) -{ - if (points_.empty() || points_.front().x - eps > x) - points_.insert(points_.begin(), Point(x, y)); -} - -Pwl::Interval Pwl::Domain() const -{ - return Interval(points_[0].x, points_[points_.size() - 1].x); -} - -Pwl::Interval Pwl::Range() const -{ - double lo = points_[0].y, hi = lo; - for (auto &p : points_) - lo = std::min(lo, p.y), hi = std::max(hi, p.y); - return Interval(lo, hi); -} - -bool Pwl::Empty() const -{ - return points_.empty(); -} - -double Pwl::Eval(double x, int *span_ptr, bool update_span) const -{ - int span = findSpan(x, span_ptr && *span_ptr != -1 - ? *span_ptr - : points_.size() / 2 - 1); - if (span_ptr && update_span) - *span_ptr = span; - return points_[span].y + - (x - points_[span].x) * (points_[span + 1].y - points_[span].y) / - (points_[span + 1].x - points_[span].x); -} - -int Pwl::findSpan(double x, int span) const -{ - // Pwls are generally small, so linear search may well be faster than - // binary, though could review this if large PWls start turning up. - int last_span = points_.size() - 2; - // some algorithms may call us with span pointing directly at the last - // control point - span = std::max(0, std::min(last_span, span)); - while (span < last_span && x >= points_[span + 1].x) - span++; - while (span && x < points_[span].x) - span--; - return span; -} - -Pwl::PerpType Pwl::Invert(Point const &xy, Point &perp, int &span, - const double eps) const -{ - assert(span >= -1); - bool prev_off_end = false; - for (span = span + 1; span < (int)points_.size() - 1; span++) { - Point span_vec = points_[span + 1] - points_[span]; - double t = ((xy - points_[span]) % span_vec) / span_vec.Len2(); - if (t < -eps) // off the start of this span - { - if (span == 0) { - perp = points_[span]; - return PerpType::Start; - } else if (prev_off_end) { - perp = points_[span]; - return PerpType::Vertex; - } - } else if (t > 1 + eps) // off the end of this span - { - if (span == (int)points_.size() - 2) { - perp = points_[span + 1]; - return PerpType::End; - } - prev_off_end = true; - } else // a true perpendicular - { - perp = points_[span] + span_vec * t; - return PerpType::Perpendicular; - } - } - return PerpType::None; -} - -Pwl Pwl::Inverse(bool *true_inverse, const double eps) const -{ - bool appended = false, prepended = false, neither = false; - Pwl inverse; - - for (Point const &p : points_) { - if (inverse.Empty()) - inverse.Append(p.y, p.x, eps); - else if (std::abs(inverse.points_.back().x - p.y) <= eps || - std::abs(inverse.points_.front().x - p.y) <= eps) - /* do nothing */; - else if (p.y > inverse.points_.back().x) { - inverse.Append(p.y, p.x, eps); - appended = true; - } else if (p.y < inverse.points_.front().x) { - inverse.Prepend(p.y, p.x, eps); - prepended = true; - } else - neither = true; - } - - // This is not a proper inverse if we found ourselves putting points - // onto both ends of the inverse, or if there were points that couldn't - // go on either. - if (true_inverse) - *true_inverse = !(neither || (appended && prepended)); - - return inverse; -} - -Pwl Pwl::Compose(Pwl const &other, const double eps) const -{ - double this_x = points_[0].x, this_y = points_[0].y; - int this_span = 0, other_span = other.findSpan(this_y, 0); - Pwl result({ { this_x, other.Eval(this_y, &other_span, false) } }); - while (this_span != (int)points_.size() - 1) { - double dx = points_[this_span + 1].x - points_[this_span].x, - dy = points_[this_span + 1].y - points_[this_span].y; - if (abs(dy) > eps && - other_span + 1 < (int)other.points_.size() && - points_[this_span + 1].y >= - other.points_[other_span + 1].x + eps) { - // next control point in result will be where this - // function's y reaches the next span in other - this_x = points_[this_span].x + - (other.points_[other_span + 1].x - - points_[this_span].y) * dx / dy; - this_y = other.points_[++other_span].x; - } else if (abs(dy) > eps && other_span > 0 && - points_[this_span + 1].y <= - other.points_[other_span - 1].x - eps) { - // next control point in result will be where this - // function's y reaches the previous span in other - this_x = points_[this_span].x + - (other.points_[other_span + 1].x - - points_[this_span].y) * dx / dy; - this_y = other.points_[--other_span].x; - } else { - // we stay in the same span in other - this_span++; - this_x = points_[this_span].x, - this_y = points_[this_span].y; - } - result.Append(this_x, other.Eval(this_y, &other_span, false), - eps); - } - return result; -} - -void Pwl::Map(std::function<void(double x, double y)> f) const -{ - for (auto &pt : points_) - f(pt.x, pt.y); -} - -void Pwl::Map2(Pwl const &pwl0, Pwl const &pwl1, - std::function<void(double x, double y0, double y1)> f) -{ - int span0 = 0, span1 = 0; - double x = std::min(pwl0.points_[0].x, pwl1.points_[0].x); - f(x, pwl0.Eval(x, &span0, false), pwl1.Eval(x, &span1, false)); - while (span0 < (int)pwl0.points_.size() - 1 || - span1 < (int)pwl1.points_.size() - 1) { - if (span0 == (int)pwl0.points_.size() - 1) - x = pwl1.points_[++span1].x; - else if (span1 == (int)pwl1.points_.size() - 1) - x = pwl0.points_[++span0].x; - else if (pwl0.points_[span0 + 1].x > pwl1.points_[span1 + 1].x) - x = pwl1.points_[++span1].x; - else - x = pwl0.points_[++span0].x; - f(x, pwl0.Eval(x, &span0, false), pwl1.Eval(x, &span1, false)); - } -} - -Pwl Pwl::Combine(Pwl const &pwl0, Pwl const &pwl1, - std::function<double(double x, double y0, double y1)> f, - const double eps) -{ - Pwl result; - Map2(pwl0, pwl1, [&](double x, double y0, double y1) { - result.Append(x, f(x, y0, y1), eps); - }); - return result; -} - -void Pwl::MatchDomain(Interval const &domain, bool clip, const double eps) -{ - int span = 0; - Prepend(domain.start, Eval(clip ? points_[0].x : domain.start, &span), - eps); - span = points_.size() - 2; - Append(domain.end, Eval(clip ? points_.back().x : domain.end, &span), - eps); -} - -Pwl &Pwl::operator*=(double d) -{ - for (auto &pt : points_) - pt.y *= d; - return *this; -} - -void Pwl::Debug(FILE *fp) const -{ - fprintf(fp, "Pwl {\n"); - for (auto &p : points_) - fprintf(fp, "\t(%g, %g)\n", p.x, p.y); - fprintf(fp, "}\n"); -} |