About generate grid map algorithm

[stevenyslins]

Dear all,

Thanks to share this code which I can run it to generate 2D grid map.
I have some question about ros_mono_sub.cc,
Does there have reference that I can refer to grid map algorithm?
Because some of code I cannot understand what it is doing, such as

void updateGridMap
{
	....
    kf_pos_x = kf_location.x*scale_factor;
    kf_pos_z = kf_location.z*scale_factor;

    kf_pos_grid_x = int(floor((kf_pos_x - grid_min_x) * norm_factor_x));
    kf_pos_grid_z = int(floor((kf_pos_z - grid_min_z) * norm_factor_z));

    if (kf_pos_grid_x < 0 || kf_pos_grid_x >= w)
        return;

    if (kf_pos_grid_z < 0 || kf_pos_grid_z >= h)
        return;
}

Thanks for your help.

[abhineet123]

The related report is attached here.
2d-grid-mapping.pdf