Function concat

source/matplot/util/common.cpp:347–352

    }

    std::vector<double> concat(const std::vector<double> &a,
                               const std::vector<double> &b) {
        std::vector<double> c(a.begin(), a.end());
        c.insert(c.end(), b.begin(), b.end());
        return c;
    }

    std::string fileread(const std::string &filename) {
        std::ifstream t(filename);