    //! Return pixel value, using cubic interpolation and periodic boundary conditions for the X-coordinate.
    Tfloat cubic_atX_p(const float fx, const int y=0, const int z=0, const int c=0) const {
      if (is_empty())
        throw CImgInstanceException(_cimg_instance
                                    "cubic_atX_p(): Empty instance.",
                                    cimg_instance);
      return _cubic_atX_p(fx,y,z,c);
Unknown