min_limit_x:   0max_limit_x:   50min_limit_y:   0max_limit_y:   50npoints_x:     5npoints_y:     5 10,20  7.5,20    5,20  2.5,20   0,20 10,15  7.5,15    5,15  2.5,15   0,15 10,10  7.5,10    5,10  2.5,10   0,10 10, 5  7.5, 5    5, 5  2.5, 5   0, 5 10, 0  7.5, 0    5, 0  2.5, 0   0, 0