def flock(self, showing_flockmates):
# NetLogo allows one to specify the units within the Gui widget.
# Here we do it explicitly by multiplying by BLOCK_SPACING().
vision_limit_in_pixels = SimEngine.gui_get('vision') * BLOCK_SPACING()
flockmates = self.agents_in_radius(vision_limit_in_pixels)
if len(flockmates) > 0:
# If showing_flockmates, create links to flockmates if they don't already exist.
if showing_flockmates:
for flockmate in flockmates:
# Don't make a link if it already exists.
if not link_exists(self, flockmate):
Link(self, flockmate, color=Color('skyblue3'))
nearest_neighbor = min(flockmates, key=lambda flockmate: self.distance_to(flockmate))
min_separation = SimEngine.gui_get('minimum separation') * BLOCK_SPACING()
if self.distance_to(nearest_neighbor) < min_separation:
self.separate(nearest_neighbor)
else:
self.align(flockmates)
self.cohere(flockmates)
def adjust_distances(self, velocity_adjustment):
#get from gui what the base distance units
dist_unit = SimEngine.gui_get(('dist_unit'))
#define how many distance units exist per screen
screen_distance_unit = sqrt(SCREEN_PIXEL_WIDTH()**2 +
SCREEN_PIXEL_HEIGHT()**2) / dist_unit
#define initial Veolocity as (0,0), forces act in the x and y directions
repulsive_force: Velocity = Velocity((0, 0))
#for all other agents excluding this instance
for agent in (World.agents - {self}):
#add their respective influence of each other element towards this element, calculate using
#this center pixel, elements center pixel and using defined units (optional repulsove flag)
repulsive_force += self.force_as_dxdy(self.center_pixel,
agent.center_pixel,
screen_distance_unit,
repulsive=True)
# Also consider repulsive force from walls.
repulsive_wall_force: Velocity = Velocity((0, 0))
horizontal_walls = [
Pixel_xy((0, 0)),
Pixel_xy((SCREEN_PIXEL_WIDTH(), 0))
]
x_pixel = Pixel_xy((self.center_pixel.x, 0))
for h_wall_pixel in horizontal_walls:
repulsive_wall_force += self.force_as_dxdy(x_pixel,
h_wall_pixel,
screen_distance_unit,
repulsive=True)
vertical_walls = [
Pixel_xy((0, 0)),
Pixel_xy((0, SCREEN_PIXEL_HEIGHT()))
]
y_pixel = Pixel_xy((0, self.center_pixel.y))
for v_wall_pixel in vertical_walls:
repulsive_wall_force += self.force_as_dxdy(y_pixel,
v_wall_pixel,
screen_distance_unit,
repulsive=True)
#calculate the attractive force generated by all the nodes connected by a link
attractive_force: Velocity = Velocity((0, 0))
for agent in (World.agents - {self}):
if link_exists(self, agent):
attractive_force += self.force_as_dxdy(self.center_pixel,
agent.center_pixel,
screen_distance_unit,
repulsive=False)
#find the final force, find out what velocity adjustment is
net_force = repulsive_force + repulsive_wall_force + attractive_force
normalized_force: Velocity = net_force / max(
[net_force.x, net_force.y, velocity_adjustment])
normalized_force *= 10
#print force values if selected
if SimEngine.gui_get('Print force values'):
print(f'{self}. \n'
f'rep-force {tuple(repulsive_force.round(2))}; \n'
f'rep-wall-force {tuple(repulsive_wall_force.round(2))}; \n'
f'att-force {tuple(attractive_force.round(2))}; \n'
f'net-force {tuple(net_force.round(2))}; \n'
f'normalized_force {tuple(normalized_force.round(2))}; \n\n')
#set the velocity of this object
self.set_velocity(normalized_force)
#take a step
self.forward()
def adjust_distances(self, velocity_adjustment):
dist_unit = 8
screen_distance_unit = sqrt(SCREEN_PIXEL_WIDTH()**2 +
SCREEN_PIXEL_HEIGHT()**2) / dist_unit
repulsive_force: Velocity = Velocity((0, 0))
for agent in (World.agents - {self}):
repulsive_force += self.force_as_dxdy(self.center_pixel,
agent.center_pixel,
screen_distance_unit,
repulsive=True)
# Also consider repulsive force from walls.
repulsive_wall_force: Velocity = Velocity((0, 0))
horizontal_walls = [
Pixel_xy((0, 0)),
Pixel_xy((SCREEN_PIXEL_WIDTH(), 0))
]
x_pixel = Pixel_xy((self.center_pixel.x, 0))
for h_wall_pixel in horizontal_walls:
repulsive_wall_force += self.force_as_dxdy(x_pixel,
h_wall_pixel,
screen_distance_unit,
repulsive=True)
vertical_walls = [
Pixel_xy((0, 0)),
Pixel_xy((0, SCREEN_PIXEL_HEIGHT()))
]
y_pixel = Pixel_xy((0, self.center_pixel.y))
for v_wall_pixel in vertical_walls:
repulsive_wall_force += self.force_as_dxdy(y_pixel,
v_wall_pixel,
screen_distance_unit,
repulsive=True)
attractive_force: Velocity = Velocity((0, 0))
for agent in (World.agents - {self}):
if link_exists(self, agent):
attractive_force += self.force_as_dxdy(self.center_pixel,
agent.center_pixel,
screen_distance_unit,
repulsive=False)
net_force = repulsive_force + repulsive_wall_force + attractive_force
normalized_force: Velocity = net_force / max(
[net_force.x, net_force.y, velocity_adjustment])
normalized_force *= 10
if SimEngine.gui_get('Print force values'):
print(f'{self}. \n'
f'rep-force {tuple(repulsive_force.round(2))}; \n'
f'rep-wall-force {tuple(repulsive_wall_force.round(2))}; \n'
f'att-force {tuple(attractive_force.round(2))}; \n'
f'net-force {tuple(net_force.round(2))}; \n'
f'normalized_force {tuple(normalized_force.round(2))}; \n\n')
self.set_velocity(normalized_force)
self.forward()
def link_nodes_for_graph(self, graph_type, nbr_nodes, ring_node_list):
"""
Link the nodes to create the requested graph.
Args:
graph_type: The name of the graph type.
nbr_nodes: The total number of nodes the user requested.
(Will be > 0 or this method won't be called.)
ring_node_list: The nodes that have been arranged in a ring.
Will contain either:
nbr_nodes - 1 if graph type is STAR or WHEEL
or nbr_nodes otherwise
Returns: None
Overrides this function from graph_framework.
"""
if graph_type is RANDOM:
link_chance = SimEngine.gui_get(LINK_PROB) / 100.0
not_checked_nodes = set(ring_node_list)
for first_node in ring_node_list:
not_checked_nodes = not_checked_nodes - {first_node}
for second_node in not_checked_nodes:
if random.random() < link_chance and not link_exists(
first_node, second_node):
Link(first_node, second_node)
type = [RING, STAR, WHEEL]
if graph_type in type:
for i in range(len(ring_node_list) - 1):
Link(ring_node_list[i], ring_node_list[i + 1])
Link(ring_node_list[-1], ring_node_list[0])
if graph_type is STAR or graph_type is WHEEL:
# implement shape if asked, needs to be a non static method to implement
# center_node = self.agent_class(shape_name=SimEngine.gui_get(SHAPE))
center_node = self.agent_class()
for node in ring_node_list:
Link(center_node, node)
if graph_type is SMALL_WORLD:
# neighborhood_size = SimEngine.gui_get(NEIGHBORHOOD_SIZE)
# for i, node in ring_node_list:
# for j in range(1, neighborhood_size + 1):
# if not link_exists(node, ring_node_list[(i + j]):
# Link(node, ring_node_list[i + j])
for i in range(len(ring_node_list)):
for j in range(1,
int(SimEngine.gui_get(NEIGHBORHOOD_SIZE)) + 1):
# makes sure to loop back if over list size
# only taking into account undirected links
# make sure to not connect nodes to themselves
if not link_exists(ring_node_list[i], ring_node_list[(i + j) % len(ring_node_list)]) and \
ring_node_list[i] is not ring_node_list[(i + j) % len(ring_node_list)]:
Link(ring_node_list[i],
ring_node_list[(i + j) % len(ring_node_list)])
# rewire chance for each link
# get rewire chance
rewire_chance = SimEngine.gui_get(LINK_PROB) / 100.0
old_links = []
# deep copy the links
for l in self.links:
old_links.append(l)
for l in old_links:
# generate random number to see if it gets rewired
if random.random() < rewire_chance:
# pick the first node in the link
# find all the nodes neigbors
# cosider yourself as a neighbor
neighbors = [l.agent_1]
for n_link in l.agent_1.all_links():
neighbors.append(n_link.other_side(l.agent_1))
# check to see if there exists any agent not considered a neighbor
if len(neighbors) < len(self.agents):
new_neighbor = choice(
list(self.agents - set(neighbors)))
# print(new_neighbor)
# remove the current link
self.links.remove(l)
# create the new link add it to the list of links to ignore
Link(l.agent_1, new_neighbor)
###preferential attachment written by Ricardo
if graph_type is PREF_ATTACHMENT:
#make a link first
Link(ring_node_list[0], ring_node_list[1])
for node in ring_node_list[2:]:
self.pref_attachment(node)