spectral_decrease.hpp

Go to the documentation of this file.

#ifndef EDSP_SPECTRAL_DECREASE_HPP
#define EDSP_SPECTRAL_DECREASE_HPP

#include <edsp/meta/expects.hpp>

namespace edsp { namespace feature { inline namespace spectral {


    template <typename ForwardIt>
    constexpr auto spectral_decrease(ForwardIt first, ForwardIt last) {
        using input_t       = typename std::iterator_traits<ForwardIt>::value_type;
        auto weighted_sum   = static_cast<input_t>(0);
        auto unweighted_sum = static_cast<input_t>(0);
        for (input_t i = 0, initial = *first; first != last; ++first, ++i) {
            weighted_sum += ((*first) - initial) / i;
            unweighted_sum += *first;
        }
        return weighted_sum / unweighted_sum;

    }

}}}


#endif //EDSP_SPECTRAL_DECREASE_HPP