roots/newton_raphson.cpp

Example to use newton_raphson class.

/*
 * Copyright 2021 MusicScience37 (Kenta Kabashima)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#include "num_collect/roots/newton_raphson.h"
 
#include "../configure_logging.h"
#include "num_collect/logging/logger.h"
#include "num_prob_collect/roots/cubic_root_test_function.h"
 
auto main() -> int {
    configure_logging();
 
    constexpr double target = 3.0;
    auto finder = num_collect::roots::newton_raphson<
        num_prob_collect::roots::cubic_root_test_function>(
        num_prob_collect::roots::cubic_root_test_function(target));
    finder.init(target);
    finder.solve();
 
    const auto logger = num_collect::logging::logger();
    logger.info()("solver:   {:15}", finder.variable());
    const double reference = std::pow(target, 1.0 / 3.0);
    logger.info()("std::pow: {:15}", reference);
 
    return 0;
}