number.hpp

#ifndef SINGLER_CLASSIC_MARKERS_NUMBER_HPP
#define SINGLER_CLASSIC_MARKERS_NUMBER_HPP
 
#include <cmath>
#include <cstddef>
 
#include "sanisizer/sanisizer.hpp"
 
namespace singler_classic_markers {
 
inline std::size_t default_number(std::size_t num_labels) {
    if (num_labels == 0) {
        return 0;
    } else {
        return sanisizer::from_float<std::size_t>(std::round(500.0 * std::pow(2.0/3.0, std::log2(static_cast<double>(num_labels)))));
    }
}
 
template<typename Index_>
Index_ get_num_keep(const std::size_t ngroups, const std::optional<std::size_t>& request) {
    std::size_t num_keep;
    if (request.has_value()) {
        num_keep = *request;
    } else {
        num_keep = default_number(ngroups);
    }
    return sanisizer::cap<Index_>(num_keep);
}
}
 
#endif