trapazoidal.hpp

Go to the documentation of this file.

 
#pragma once
 
#include <functional>
 
#include "NumCpp/Core/Types.hpp"
 
namespace nc::integrate
{
    //============================================================================
    // Method Description:
    inline double trapazoidal(const double                         low,
                              const double                         high,
                              const uint32                         n,
                              const std::function<double(double)>& f) noexcept
    {
        const double width = (high - low) / static_cast<double>(n);
 
        double trapezoidal_integral = 0.;
        for (uint32 step = 0; step < n; ++step)
        {
            const double x1 = low + static_cast<double>(step) * width;
            const double x2 = low + static_cast<double>(step + 1) * width;
 
            trapezoidal_integral += 0.5 * (x2 - x1) * (f(x1) + f(x2));
        }
 
        return trapezoidal_integral;
    }
} // namespace nc::integrate