chromium/third_party/webrtc/rtc_tools/frame_analyzer/linear_least_squares.cc

/*
 *  Copyright (c) 2018 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#include "rtc_tools/frame_analyzer/linear_least_squares.h"

#include <math.h>

#include <cstdint>
#include <cstdlib>
#include <functional>
#include <numeric>
#include <type_traits>
#include <utility>

#include "rtc_base/checks.h"
#include "rtc_base/logging.h"

namespace webrtc {
namespace test {

Matrix;

namespace {

template <typename R, typename T>
R DotProduct(const std::valarray<T>& a, const std::valarray<T>& b) { … }

// Calculates a^T * b.
template <typename R, typename T>
Matrix<R> MatrixMultiply(const Matrix<T>& a, const Matrix<T>& b) { … }

template <typename T>
Matrix<T> Transpose(const Matrix<T>& matrix) { … }

// Convert valarray from type T to type R.
template <typename R, typename T>
std::valarray<R> ConvertTo(const std::valarray<T>& v) { … }

// Convert valarray Matrix from type T to type R.
template <typename R, typename T>
Matrix<R> ConvertTo(const Matrix<T>& mat) { … }

// Convert from valarray Matrix back to the more conventional std::vector.
template <typename T>
std::vector<std::vector<T>> ToVectorMatrix(const Matrix<T>& m) { … }

// Create a valarray Matrix from a conventional std::vector.
template <typename T>
Matrix<T> FromVectorMatrix(const std::vector<std::vector<T>>& mat) { … }

// Returns `matrix_to_invert`^-1 * `right_hand_matrix`. `matrix_to_invert` must
// have square size.
Matrix<double> GaussianElimination(Matrix<double> matrix_to_invert,
                                   Matrix<double> right_hand_matrix) { … }

}  // namespace

IncrementalLinearLeastSquares::IncrementalLinearLeastSquares() = default;
IncrementalLinearLeastSquares::~IncrementalLinearLeastSquares() = default;

void IncrementalLinearLeastSquares::AddObservations(
    const std::vector<std::vector<uint8_t>>& x,
    const std::vector<std::vector<uint8_t>>& y) { … }

std::vector<std::vector<double>>
IncrementalLinearLeastSquares::GetBestSolution() const { … }

}  // namespace test
}  // namespace webrtc