Function to_positive_radian

source/matplot/util/common.cpp:412–419

    }

    double to_positive_radian(double radian) {
        radian = std::fmod(radian, pi * 2.);
        while (radian < 0) {
            // pretty sure this comparison is valid for doubles and floats
            radian += pi * 2.;
        }
        return radian;
    }

    double vector_radians(double x, double y) {
        return to_positive_radian(atan2(y, x));