class WolfSheepPredation(Model):
'''
Wolf-Sheep Predation Model
'''
height = 20
width = 20
initial_sheep = 100
initial_wolves = 50
sheep_reproduce = 0.04
wolf_reproduce = 0.05
wolf_gain_from_food = 20
grass = False
grass_regrowth_time = 30
sheep_gain_from_food = 4
verbose = False # Print-monitoring
def __init__(self,
height=20,
width=20,
initial_sheep=100,
initial_wolves=50,
sheep_reproduce=0.04,
wolf_reproduce=0.05,
wolf_gain_from_food=20,
grass=False,
grass_regrowth_time=30,
sheep_gain_from_food=4):
'''
Create a new Wolf-Sheep model with the given parameters.
Args:
initial_sheep: Number of sheep to start with
initial_wolves: Number of wolves to start with
sheep_reproduce: Probability of each sheep reproducing each step
wolf_reproduce: Probability of each wolf reproducing each step
wolf_gain_from_food: Energy a wolf gains from eating a sheep
grass: Whether to have the sheep eat grass for energy
grass_regrowth_time: How long it takes for a grass patch to regrow
once it is eaten
sheep_gain_from_food: Energy sheep gain from grass, if enabled.
'''
# Set parameters
self.height = height
self.width = width
self.initial_sheep = initial_sheep
self.initial_wolves = initial_wolves
self.sheep_reproduce = sheep_reproduce
self.wolf_reproduce = wolf_reproduce
self.wolf_gain_from_food = wolf_gain_from_food
self.grass = grass
self.grass_regrowth_time = grass_regrowth_time
self.sheep_gain_from_food = sheep_gain_from_food
self.schedule = RandomActivationByBreed(self)
self.grid = MultiGrid(self.height, self.width, torus=True)
self.datacollector = DataCollector({
"Wolves":
lambda m: m.schedule.get_breed_count(Wolf),
"Sheep":
lambda m: m.schedule.get_breed_count(Sheep)
})
# Create sheep:
for i in range(self.initial_sheep):
x = random.randrange(self.width)
y = random.randrange(self.height)
energy = random.randrange(2 * self.sheep_gain_from_food)
sheep = Sheep(self.grid, (x, y), True, energy)
self.grid.place_agent(sheep, (x, y))
self.schedule.add(sheep)
# Create wolves
for i in range(self.initial_wolves):
x = random.randrange(self.width)
y = random.randrange(self.height)
energy = random.randrange(2 * self.wolf_gain_from_food)
wolf = Wolf(self.grid, (x, y), True, energy)
self.grid.place_agent(wolf, (x, y))
self.schedule.add(wolf)
# Create grass patches
if self.grass:
for agent, x, y in self.grid.coord_iter():
fully_grown = random.choice([True, False])
if fully_grown:
countdown = self.grass_regrowth_time
else:
countdown = random.randrange(self.grass_regrowth_time)
patch = GrassPatch(fully_grown, countdown)
self.grid.place_agent(patch, (x, y))
self.schedule.add(patch)
self.running = True
def step(self):
self.schedule.step()
self.datacollector.collect(self)
if self.verbose:
print([
self.schedule.time,
self.schedule.get_breed_count(Wolf),
self.schedule.get_breed_count(Sheep)
])
def run_model(self, step_count=200):
if self.verbose:
print('Initial number wolves: ',
self.schedule.get_breed_count(Wolf))
print('Initial number sheep: ',
self.schedule.get_breed_count(Sheep))
for i in range(step_count):
self.step()
if self.verbose:
print('')
print('Final number wolves: ', self.schedule.get_breed_count(Wolf))
print('Final number sheep: ', self.schedule.get_breed_count(Sheep))
class WolfSheep(Model):
'''
Wolf-Sheep Predation Model
'''
height = 20
width = 20
initial_sheep = 100
initial_wolves = 50
sheep_reproduce = 0.04
wolf_reproduce = 0.05
wolf_gain_from_food = 20
grass = False
grass_regrowth_time = 30
sheep_gain_from_food = 4
verbose = False # Print-monitoring
description = 'A model for simulating wolf and sheep (predator-prey) ecosystem modelling.'
def __init__(self, height=20, width=20,
initial_sheep=100, initial_wolves=50,
sheep_reproduce=0.04, wolf_reproduce=0.05,
wolf_gain_from_food=20,
grass=False, grass_regrowth_time=30, sheep_gain_from_food=4):
'''
Create a new Wolf-Sheep model with the given parameters.
Args:
initial_sheep: Number of sheep to start with
initial_wolves: Number of wolves to start with
sheep_reproduce: Probability of each sheep reproducing each step
wolf_reproduce: Probability of each wolf reproducing each step
wolf_gain_from_food: Energy a wolf gains from eating a sheep
grass: Whether to have the sheep eat grass for energy
grass_regrowth_time: How long it takes for a grass patch to regrow
once it is eaten
sheep_gain_from_food: Energy sheep gain from grass, if enabled.
'''
super().__init__()
# Set parameters
self.height = height
self.width = width
self.initial_sheep = initial_sheep
self.initial_wolves = initial_wolves
self.sheep_reproduce = sheep_reproduce
self.wolf_reproduce = wolf_reproduce
self.wolf_gain_from_food = wolf_gain_from_food
self.grass = grass
self.grass_regrowth_time = grass_regrowth_time
self.sheep_gain_from_food = sheep_gain_from_food
self.schedule = RandomActivationByBreed(self)
self.grid = MultiGrid(self.height, self.width, torus=True)
self.datacollector = DataCollector(
{"Wolves": lambda m: m.schedule.get_breed_count(Wolf),
"Sheep": lambda m: m.schedule.get_breed_count(Sheep)})
# Create sheep:
for i in range(self.initial_sheep):
x = self.random.randrange(self.width)
y = self.random.randrange(self.height)
energy = self.random.randrange(2 * self.sheep_gain_from_food)
sheep = Sheep(self.next_id(), (x, y), self, True, energy)
self.grid.place_agent(sheep, (x, y))
self.schedule.add(sheep)
# Create wolves
for i in range(self.initial_wolves):
x = self.random.randrange(self.width)
y = self.random.randrange(self.height)
energy = self.random.randrange(2 * self.wolf_gain_from_food)
wolf = Wolf(self.next_id(), (x, y), self, True, energy)
self.grid.place_agent(wolf, (x, y))
self.schedule.add(wolf)
# Create grass patches
if self.grass:
for agent, x, y in self.grid.coord_iter():
fully_grown = self.random.choice([True, False])
if fully_grown:
countdown = self.grass_regrowth_time
else:
countdown = self.random.randrange(self.grass_regrowth_time)
patch = GrassPatch(self.next_id(), (x, y), self,
fully_grown, countdown)
self.grid.place_agent(patch, (x, y))
self.schedule.add(patch)
self.running = True
self.datacollector.collect(self)
def step(self):
self.schedule.step()
# collect data
self.datacollector.collect(self)
if self.verbose:
print([self.schedule.time,
self.schedule.get_breed_count(Wolf),
self.schedule.get_breed_count(Sheep)])
def run_model(self, step_count=200):
if self.verbose:
print('Initial number wolves: ',
self.schedule.get_breed_count(Wolf))
print('Initial number sheep: ',
self.schedule.get_breed_count(Sheep))
for i in range(step_count):
self.step()
if self.verbose:
print('')
print('Final number wolves: ',
self.schedule.get_breed_count(Wolf))
print('Final number sheep: ',
self.schedule.get_breed_count(Sheep))
class WolfSheepPredation(Model):
'''
Wolf-Sheep Predation Model
'''
verbose = False # Print-monitoring
def __init__(self, height=20, width=20,
initial_sheep=150, initial_wolves=10,
sheep_reproduce=1, wolf_reproduce=40,
wolf_gain_from_food=15,
grass_regrowth_time=20, sheep_gain_from_food=4):
'''
Create a new Wolf-Sheep model with the given parameters.
Args:
initial_sheep: Number of sheep to start with
initial_wolves: Number of wolves to start with
sheep_reproduce: Энергия для генерации новой овечки, забираемая у родителей
wolf_reproduce: --//-- волчонка --//--
wolf_gain_from_food: Energy a wolf gains from eating a sheep
grass_regrowth_time: How long it takes for a grass patch to regrow
once it is eaten
sheep_gain_from_food: Energy sheep gain from grass
'''
# Set parameters
self.height = height
self.width = width
self.initial_sheep = initial_sheep
self.initial_wolves = initial_wolves
self.sheep_reproduce = sheep_reproduce
self.wolf_reproduce = wolf_reproduce
self.wolf_gain_from_food = wolf_gain_from_food
self.grass_regrowth_time = grass_regrowth_time
self.sheep_gain_from_food = sheep_gain_from_food
self.schedule = RandomActivationByBreed(self)
self.grid = MultiGrid(self.height, self.width, torus=True)
self.datacollector = DataCollector(
{"Wolves": lambda m: m.schedule.get_breed_count(Wolf),
"Sheep": lambda m: m.schedule.get_breed_count(Sheep)})
# Create sheep:
for i in range(self.initial_sheep):
x = random.randrange(self.width)
y = random.randrange(self.height)
energy = random.randrange(2 * self.sheep_gain_from_food)
sheep = Sheep((x, y), self, True, energy)
self.grid.place_agent(sheep, (x, y))
self.schedule.add(sheep)
# Create wolves
for i in range(self.initial_wolves):
x = random.randrange(self.width)
y = random.randrange(self.height)
energy = random.randrange(2 * self.wolf_gain_from_food)
wolf = Wolf((x, y), self, True, energy)
self.grid.place_agent(wolf, (x, y))
self.schedule.add(wolf)
# Create grass patches
for agent, x, y in self.grid.coord_iter():
fully_grown = random.choice([True, False])
if fully_grown:
countdown = self.grass_regrowth_time
else:
countdown = random.randrange(self.grass_regrowth_time)
patch = GrassPatch((x, y), self, fully_grown, countdown)
self.grid.place_agent(patch, (x, y))
self.schedule.add(patch)
self.running = True
def step(self):
self.schedule.step()
self.datacollector.collect(self)
if self.verbose:
print([self.schedule.time,
self.schedule.get_breed_count(Wolf),
self.schedule.get_breed_count(Sheep)])
def run_model(self, step_count=200):
if self.verbose:
print('Initial number wolves: ',
self.schedule.get_breed_count(Wolf))
print('Initial number sheep: ',
self.schedule.get_breed_count(Sheep))
for i in range(step_count):
self.step()
if self.verbose:
print('')
print('Final number wolves: ',
self.schedule.get_breed_count(Wolf))
print('Final number sheep: ',
self.schedule.get_breed_count(Sheep))
class WolfSheepPredation(Model):
'''
Wolf-Sheep Predation Model
'''
height = 20
width = 20
initial_sheep = 100
initial_wolves = 50
min_initial_age = -1 # set to -1 to indicate newborns, as on first step it will increment and become 0
sheep_initial_age_limit = Sheep.max_age * 0.75
wolf_initial_age_limit = Wolf.max_age * 0.75
sheep_reproduce = 0.04
wolf_reproduce = 0.05
wolf_gain_from_food = 20
grass = False
grass_regrowth_time = 30
sheep_gain_from_food = 4
verbose = False # Print-monitoring
description = 'A model for simulating wolf and sheep (predator-prey) ecosystem modelling.'
def __init__(self, height=20, width=20,
initial_sheep=100, initial_wolves=50,
sheep_reproduce=0.04, wolf_reproduce=0.05,
wolf_gain_from_food=20,
grass=False, grass_regrowth_time=30, sheep_gain_from_food=4,
sheep_initial_age_limit=Sheep.max_age * 0.75, wolf_initial_age_limit=Wolf.max_age * 0.75):
'''
Create a new Wolf-Sheep model with the given parameters.
Args:
initial_sheep: Number of sheep to start with
initial_wolves: Number of wolves to start with
sheep_reproduce: Probability of each sheep reproducing each step
wolf_reproduce: Probability of each wolf reproducing each step
wolf_gain_from_food: Energy a wolf gains from eating a sheep
grass: Whether to have the sheep eat grass for energy
grass_regrowth_time: How long it takes for a grass patch to regrow
once it is eaten
sheep_gain_from_food: Energy sheep gain from grass, if enabled.
'''
# Set parameters
self.height = height
self.width = width
self.initial_sheep = initial_sheep
self.initial_wolves = initial_wolves
self.sheep_initial_age_limit = sheep_initial_age_limit
self.wolf_initial_age_limit = wolf_initial_age_limit
self.sheep_reproduce = sheep_reproduce
self.wolf_reproduce = wolf_reproduce
self.reproduces_by_type = dict([
(Sheep.__name__, sheep_reproduce),
(Wolf.__name__, wolf_reproduce),
])
self.wolf_gain_from_food = wolf_gain_from_food
self.grass = grass
self.grass_regrowth_time = grass_regrowth_time
self.sheep_gain_from_food = sheep_gain_from_food
self.schedule = RandomActivationByBreed(self)
self.grid = MultiGrid(self.height, self.width, torus=True)
self.datacollector = DataCollector(
{"Wolves": lambda m: m.schedule.get_breed_count(Wolf),
"Sheep": lambda m: m.schedule.get_breed_count(Sheep)})
self.datacollector_ages = DataCollector(
{"Wolves": lambda m: m.schedule.get_breed_average_age(Wolf),
"Sheep": lambda m: m.schedule.get_breed_average_age(Sheep)})
# Create sheep:
for i in range(self.initial_sheep):
x = random.randrange(self.width)
y = random.randrange(self.height)
energy = random.randrange(2 * self.sheep_gain_from_food)
age = random.randint(self.min_initial_age, sheep_initial_age_limit)
sheep = Sheep((x, y), self, True, energy, age)
self.grid.place_agent(sheep, (x, y))
self.schedule.add(sheep)
# Create wolves
for i in range(self.initial_wolves):
x = random.randrange(self.width)
y = random.randrange(self.height)
energy = random.randrange(2 * self.wolf_gain_from_food)
age = random.randint(self.min_initial_age, wolf_initial_age_limit)
wolf = Wolf((x, y), self, True, energy, age)
self.grid.place_agent(wolf, (x, y))
self.schedule.add(wolf)
# Create grass patches
if self.grass:
for agent, x, y in self.grid.coord_iter():
fully_grown = random.choice([True, False])
if fully_grown:
countdown = self.grass_regrowth_time
else:
countdown = random.randrange(self.grass_regrowth_time)
patch = GrassPatch((x, y), self, fully_grown, countdown)
self.grid.place_agent(patch, (x, y))
self.schedule.add(patch)
self.running = True
self.datacollector.collect(self)
self.datacollector_ages.collect(self)
def step(self):
self.schedule.step()
# collect data
self.datacollector.collect(self)
self.datacollector_ages.collect(self)
if self.verbose:
print([self.schedule.time,
self.schedule.get_breed_count(Wolf),
self.schedule.get_breed_count(Sheep)])
def run_model(self, step_count=200):
if self.verbose:
print('Initial number wolves: ',
self.schedule.get_breed_count(Wolf))
print('Initial number sheep: ',
self.schedule.get_breed_count(Sheep))
for i in range(step_count):
self.step()
if self.verbose:
print('')
print('Final number wolves: ',
self.schedule.get_breed_count(Wolf))
print('Final number sheep: ',
self.schedule.get_breed_count(Sheep))
def can_reproduce(self, agent, seed=None):
"""Indicates whether an agent can reproduce based on the probability for its type.
Arguments:
agent (Sheep|Wolf): agent to check if it can reproduce
seed (int, optional): seed used to retrieve the random number used to determined
if the agent can reproduce. This allows the same check to be called multiple times
for the same agent without having different results
"""
if seed is not None:
random.seed(seed)
return random.random() < self.reproduces_by_type[type(agent).__name__]