def plurality_value(examples):
"""
Return the most popular target value for this set of examples.
(If target is binary, this is the majority; otherwise plurality).
"""
popular = argmax_random_tie(values[target], key=lambda v: count(target, v, examples))
return DecisionLeaf(popular)
def hill_climbing(self, problem, map_canvas):
""" hill climbing where number of neighbors is taken as user input """
def find_neighbors(state, number_of_neighbors=100):
""" finds neighbors using two_opt method """
neighbors = []
for i in range(number_of_neighbors):
new_state = problem.two_opt(state)
neighbors.append(Node(new_state))
state = new_state
return neighbors
current = Node(problem.initial)
while(1):
neighbors = find_neighbors(current.state, self.no_of_neighbors.get())
neighbor = utils.argmax_random_tie(neighbors, key=lambda node: problem.value(node.state))
map_canvas.delete('poly')
points = []
for city in current.state:
points.append(self.frame_locations[city][0])
points.append(self.frame_locations[city][1])
map_canvas.create_polygon(points, outline='red', width=3, fill='', tag='poly')
neighbor_points = []
for city in neighbor.state:
neighbor_points.append(self.frame_locations[city][0])
neighbor_points.append(self.frame_locations[city][1])
map_canvas.create_polygon(neighbor_points, outline='red', width=1, fill='', tag='poly')
map_canvas.update()
map_canvas.after(self.speed.get())
if problem.value(neighbor.state) > problem.value(current.state):
current.state = neighbor.state
self.cost.set("Cost = " + str('%0.3f' % (-1 * problem.value(current.state))))
def hill_climbing(problem):
current = Node(problem.initial)
while True:
neighbors = current.expand(problem)
if not neighbors:
break
neighbor = argmax_random_tie(neighbors,
key=lambda node: problem.value(node.state))
if problem.value(neighbor.state) <= problem.value(current.state):
break
current = neighbor
return current.state
def hill_climbing(self, problem, map_canvas):
""" hill climbing where number of neighbors is taken as user input """
def find_neighbors(state, number_of_neighbors=100):
""" finds neighbors using two_opt method """
neighbors = []
for i in range(number_of_neighbors):
new_state = problem.two_opt(state)
neighbors.append(Node(new_state))
state = new_state
return neighbors
current = Node(problem.initial)
tiempo_inicial = time()
while (1):
print("kd")
neighbors = find_neighbors(current.state,
self.no_of_neighbors.get())
neighbor = utils.argmax_random_tie(
neighbors, key=lambda node: problem.value(node.state))
map_canvas.delete('poly')
points = []
for city in current.state:
points.append(self.frame_locations[city][0])
points.append(self.frame_locations[city][1])
map_canvas.create_polygon(points,
outline='red',
width=3,
fill='',
tag='poly')
neighbor_points = []
for city in neighbor.state:
neighbor_points.append(self.frame_locations[city][0])
neighbor_points.append(self.frame_locations[city][1])
map_canvas.create_polygon(neighbor_points,
outline='red',
width=1,
fill='',
tag='poly')
map_canvas.update()
map_canvas.after(self.speed.get())
if problem.value(neighbor.state) > problem.value(current.state):
current.state = neighbor.state
self.cost.set("Cost = " +
str('%0.3f' %
(-1 * problem.value(current.state))))
tiempo_final = time()
tiempo_ejecucion = tiempo_final - tiempo_inicial
print('El tiempo de ejecucion fue:', tiempo_ejecucion) #En segundos
def hill_climbing(problem):
"""From the initial node, keep choosing the neighbor with highest value"""
current = Node(problem.initial)
while True:
neighbors = current.expand(problem)
if not neighbors:
break
neighbor = argmax_random_tie(
neighbors, key=lambda node: problem.value(node.state))
if problem.value(neighbor.state) <= problem.value(current.state):
break
current = neighbor
return current.state
def hill_climbing(problem):
"""From the initial node, keep choosing the neighbor with highest value,
stopping when no neighbor is better. [Fig. 4.2]"""
current = Node(problem.initial)
while True:
neighbors = current.expand(problem)
if not neighbors:
break
neighbor = argmax_random_tie(neighbors,
lambda node: problem.value(node.state))
if problem.value(neighbor.state) <= problem.value(current.state):
break
current = neighbor
return current.state
def hill_climbing(problem):
"""From the initial node, keep choosing the neighbor with highest value,
stopping when no neighbor is better. [Figure 4.2]"""
current = Node(problem.initial)
while True:
neighbors = current.expand(problem)
if not neighbors:
break
neighbor = argmax_random_tie(
neighbors, key=lambda node: problem.value(node.state))
if problem.value(neighbor.state) <= problem.value(current.state):
break
current = neighbor
print('.', end='', flush=True)
return current.state
def alphabeta_search(state, game, d=4, cutoff_test=None, eval_fn=None):
"""Search game to determine best action; use alpha-beta pruning.
This version cuts off search and uses an evaluation function."""
player = game.to_move(state)
def max_value(state, alpha, beta, depth):
if cutoff_test(state, depth):
return eval_fn(state)
v = -infinity
succ = game.successors(state)
for (a, s) in succ:
v = max(v, min_value(s, alpha, beta, depth+1))
if v >= beta:
succ.close()
return v
alpha = max(alpha, v)
return v
def min_value(state, alpha, beta, depth):
if cutoff_test(state, depth):
return eval_fn(state)
v = infinity
succ = game.successors(state)
for (a, s) in succ:
v = min(v, max_value(s, alpha, beta, depth+1))
if v <= alpha:
succ.close()
return v
beta = min(beta, v)
return v
# Body of alphabeta_search starts here:
# The default test cuts off at depth d or at a terminal state
cutoff_test = (cutoff_test or
(lambda state,depth: depth>d or game.terminal_test(state)))
eval_fn = eval_fn or (lambda state: game.utility(player, state))
action, state = argmax_random_tie(game.successors(state),
lambda ((a, s)): min_value(s, -infinity,
infinity, 0))
return action
def decision_tree_learning(examples, attributes, parent_examples, classes_list):
#
# Checks if the given examples have the same classification
# examples: [{exampledictionary}, 'class']
# return: pair with (true/false, the classification)
sameclass,classification = is_same(examples)
if len(examples)==0: return Tree(plurality_value(parent_examples))
elif sameclass: return Tree(classification)
elif len(attributes)==0: return Tree(plurality_value(examples))
else:
# create a list of the attribute names (attributes.keys()), calculate the importance of each of
# them, then get the one with highest value
#attributename = argmax(attributes.keys(), lambda ((a)): importance(a, examples, attributes,classes_list))
attributename = argmax_random_tie(attributes.keys(), lambda ((a)): importance(a, examples, attributes,classes_list))
tree = Tree(attributename)
for vk in attributes[attributename]:
exs = []
for example in examples:
exvalues = example[0]
if exvalues[attributename] == vk:
exs.append(example)
newattributes = remove_dict_entry(attributename, attributes) #remove_member(attribute, attibutes)
subtree = decision_tree_learning(exs, newattributes, examples,classes_list)
#subtree = decision_tree_learning(exs, attributes, examples,classes_list)
# make a label by combining attribute name with a spacific
# attribute value
label = str(vk) #{attribute.key:vk}
tree.add_branch(label, subtree)
return tree
def choose_attribute(attrs, examples):
"""Choose the attribute with the highest information gain."""
return argmax_random_tie(attrs,
key=lambda a: information_gain(a, examples))
def choose_attribute(attrs, examples):
"Choose the attribute with the highest information gain."
return argmax_random_tie(attrs,
key=lambda a: information_gain(a, examples))
def plurality_value(examples):
"""Return the most popular target value for this set of examples.
(If target is binary, this is the majority; otherwise plurality.)"""
popular = argmax_random_tie(values[target],
key=lambda v: count(target, v, examples))
return DecisionLeaf(popular)
def plurality_value(examples):
popular = argmax_random_tie(values[target],
key=lambda v: count(target, v, examples))
return DecisionLeaf(popular)
def arbitrate(self):
self.most_desirable = argmax_random_tie(self.evaluators, lambda e: e.calculate_desirability())
self.most_desirable.set_goal()
def arbitrate(self):
self.most_desirable = argmax_random_tie(
self.evaluators, lambda e: e.calculate_desirability())
self.most_desirable.set_goal()
def plurality_value(self, examples):
"""Return the most popular target value for this set of examples."""
return argmax_random_tie(self.values[self.target], key=lambda v: self.count(self.target, v, examples))