Function wrap01

cpp_core/src/symmetry.cpp:15–19

Wrap to [0, 1)

// Wrap to [0, 1)
double wrap01(double x) {
    double y = std::fmod(x, 1.0);
    if (y < 0.0) y += 1.0;
    return y;
}

// Periodic distance
double periodic_delta(double a, double b) {