"""
sand_model.py
Abelian sand that has avalanches in interesting patterns.
"""
from math import floor
import indra.display_methods as disp
import indra.grid_agent as ga
import indra.grid_env as ge
X = 0
Y = 1
MAX_SAND = 4
FULL_NEIGHBORHOOD = 4
class SandAgent(ga.GridAgent):
"""
An agent that collects sand particles until its stack collapses
onto its neighbors.
"""
def __init__(self, name, goal, cell, sand_amt=0):
super().__init__(name, goal)
self.cell = cell
self.sand_amt = sand_amt
self.ntype = str(self.sand_amt) # we get our color from our sand amount
def act(self):
"""
Our main action goes here, in this case,
tumbling sand onto our neighbors.
"""
if self.sand_amt >= MAX_SAND:
i = 0
for neighbor in self.neighbor_iter(moore=False, save_hood=True, shuffle=True):
i += 1
if self.sand_amt > 0:
neighbor.add_grains(1)
self.sand_amt -= 1
if self.sand_amt > 0 and i < FULL_NEIGHBORHOOD:
for j in range(i, FULL_NEIGHBORHOOD):
"""
If at edge, sand "tumbles off."
"""
if self.sand_amt > 0:
self.sand_amt -= 1
def postact(self):
"""
Here we are going to set our type.
"""
new_type = str(self.sand_amt)
if self.ntype != new_type:
old_type = self.ntype
self.set_type(new_type)
self.env.change_agent_type(self, old_type, new_type)
def add_grains(self, amt):
"""
Get some sand.
"""
self.sand_amt += amt
def to_json(self):
safe_json = super().to_json()
safe_json["sand_amt"] = self.sand_amt
return safe_json
class SandEnv(ge.GridEnv):
"""
An environment for spilling sand all over the place.
"""
def __init__(self, name, width, height, model_nm=None, props=None):
super().__init__(name, width, height, torus=False,
model_nm=model_nm, postact=True, props=props)
self.center_agent = None
self.set_var_color('0', disp.BLACK)
self.set_var_color('1', disp.MAGENTA)
self.set_var_color('2', disp.BLUE)
self.set_var_color('3', disp.CYAN)
self.set_var_color('4', disp.RED)
self.set_var_color('5', disp.YELLOW)
self.set_var_color('6', disp.GREEN)
center_x = floor(self.width // 2)
center_y = floor(self.height // 2)
print("center = %i, %i" % (center_x, center_y))
for cell in self:
(x, y) = cell.coords
agent = SandAgent("Grainy", "Hold sand", cell)
self.add_agent(agent, position=False)
if x == center_x and y == center_y:
self.center_agent = agent
def from_json(self, json_input):
super().from_json(json_input)
self.set_var_color('0', disp.BLACK)
self.set_var_color('1', disp.MAGENTA)
self.set_var_color('2', disp.BLUE)
self.set_var_color('3', disp.CYAN)
self.set_var_color('4', disp.RED)
self.set_var_color('5', disp.YELLOW)
self.set_var_color('6', disp.GREEN)
def step(self, random=True):
super().step(random=random)
self.center_agent.add_grains(1)
def run(self, periods=-1, random=True):
return super().run(periods=periods, random=True)
def restore_agent(self, agent_json):
new_agent = SandAgent(name=agent_json["name"],
goal=agent_json["goal"],
cell=ge.Cell.from_json(agent_json["cell"]),
sand_amt=agent_json["sand_amt"])
(x, y) = new_agent.cell.coords
self.add_agent_from_json(new_agent, agent_json, x=x, y=y)
center_x = floor(self.width // 2)
center_y = floor(self.height // 2)
if x == center_x and y == center_y:
self.center_agent = new_agent
