boundary_types = p,+g
boundary_values = 0,-1
initial_gradients =         0.3,  1.4,  0.4, -0.5,   -2,   +2,  0.4, -0.5,   10,  0.4, -0.5,   -2,   +2,  0.4, -0.5,   10,  0.4, -0.5,   -2,   +2
reflection_path =   (3,4),(5,5),(4,5),(3,6),(3,7),(4,8),(5,8),(6,7),(6,6),(5,5),(4,6),(4,7),(5,8),(6,8),(7,7),(7,6),(6,5),(5,6),(5,7),(6,8),(7,8)  
grid_size = 9
max_radius = 70%
